This oblique perspective view of Nectaris Fossae and Protva Valles on Mars was generated from the digital terrain model and the nadir and colour channels of the High Resolution Stereo Camera on ESA’s Mars Express. A large impact crater features in the bottom left, stretching partially out of frame, with four smaller craters dotted across to its right. Some textures and grooves can be seen in the more distant surface.

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Credits: ESA/DLR/FU Berlin, CC BY-SA 3.0 IGO

Part of the Frisian Islands, a low-lying archipelago just off the coast of northern Europe, is visible in this image captured by the Copernicus Sentinel-2 mission.

The Frisian Islands stretch from the northwest of the Netherlands through Germany to the west of Denmark. Although they are considered a single physical feature, they are divided into West, East and North Frisian Islands – with the North Frisian Islands visible here.

The North Frisian Islands are split between Germany and Denmark. There are four larger islands that make up the archipelago: Sylt, Föhr, Amrum, and Pellworm.

Sylt, the largest of the archipelago, is around 100 sq km and is known for its distinctive shape of its shoreline. Sylt extends in length more than 35 km and, in some places, is only 1 km wide. A sandy beach stretches across the islands’ west coast, however it has begun to erode owing to storm tides. The northernmost island of Germany, it is connected to the mainland by the Hindenburgdamm, an 11 km-long causeway.

The Wadden Sea on the islands’ east side, between Sylt and the mainland, is part of the Schleswig-Holstein Wadden Sea National Park and has been a nature reserve and bird sanctuary since 1935.

The islands of Föhr and Amrum are visible southeast of Sylt. The larger Föhr is called the ‘Green Island’ due to it being sheltered from the storms of the North Sea by its neighbouring islands. The island of Amrum features an extended beach area along its west coast, which faces the open North Sea. The east coast borders to mud flats and tidal creeks of the Wadden Sea.

The three white islands visible below Amrum are the North Frisian Barrier Islands. These sand banks, or shoals, act as a natural breakwater for the smaller islands closer to land. Just east of these lies the island of Pellworm.

North of Sylt lie the Danish islands of Rømø, Mandø, and, lastly, Fanø. In the top-left of the image, a large algal bloom is visible in emerald green. Harmful algal blooms caused by excessive growth of marine algae have occurred in the North Sea in recent years, with satellite data being used to track their growth and spread. These data can then be used to help develop alert systems to mitigate against damaging impacts for tourism and fishing industries.

This image, captured on 1 June 2020, is also featured on the Earth from Space video programme.

Credits: contains modified Copernicus Sentinel data (2020), processed by ESA, CC BY-SA 3.0 IGO

Someone decked the skies with boughs of sprites.

The red jellyfish in the sky is a unique red sprite high above a storm across the southern plains of the United States.

Taken in the early hours of 21 October by outdoor photographer Paul Smith, red sprites, along with blue jets and elves, are elusive electrical discharges in the upper atmosphere that are difficult to study as they occur over thunderstorms and propagate out into space.

“There were some very strong events and many dancing sprites as the storms matured,” says Paul.

“I was so amazed to capture some very bright reflections in the lake I was shooting from. I was out until the early hours of the morning and got home at 5:00, but so worth it!” The photo was taken from Lake Acadia, Oklahoma. Watch a video of the storm here.

Sightings of these elusive high altitude optical phenomena had long been based on hearsay and appeared to be linked with thunderstorms. First camera images of red sprites were obtained about 30 years ago. The scientific community was intrigued and wanted to learn more, leading to the creation of an observatory that is now aboard the International Space Station.

Called the Atmosphere-Space Interactions Monitor, or ASIM, the suite of instruments includes optical cameras and photometers to capture red sprites and other high altitude luminous events as well as lightning. ASIM also carries a Gamma-ray detector to study so-called Terrestrial Gamma-ray Flashes (TGFs).

All these instruments are mounted together outside the European Columbus module and look downwards towards the Earth. The combination of optical and Gamma-ray detectors in the same payload makes it possible to describe the lightning processes that lead to TGF emissions. ASIM provides the highest ever spatial and temporal resolution for the study of electrical activity linked to thunderstorms.

New data from ASIM will improve our understanding of the effect of thunderstorms on the atmosphere and thus contribute to more accurate climate models.

The data ASIM is generating has been made available to the public for the first time and can be consulted at the ASIM Science Data Center. A recent paper was also published in Science magazine.

Though they are difficult to detect due to their faintness and the fact that they disappear within milliseconds, the conditions from Earth were just right to catch these sprites in action.

You can find more of Paul’s work on his website, Facebook, Twitter, and YouTube.

Credits: Paul M. Smith

Observations by the NASA/ESA Hubble Space Telescope recently revealed water vapour in the atmosphere of Ganymede, one of Jupiter’s moons. A new analysis of archival images and spectra has now revealed that water vapour is also present in the atmosphere of Jupiter’s icy moon Europa. The analysis found that a water vapour atmosphere is present only on one hemisphere of the moon. This result advances our understanding of the atmospheric structure of icy moons, and helps lay the groundwork for upcoming science missions which will explore Jupiter’s icy moons.

Europa — one of Jupiter’s 79 moons — is both the sixth closest moon to Jupiter and the sixth largest moon in the Solar System. It is an icy orb larger than the dwarf planet Pluto with a smooth, icy surface scarred by cracks and fissures. The surface of the moon is a bleak environment with an average temperature of −171 °C and only a tenuous atmosphere. However, astronomers suspect that Europa harbours a vast ocean underneath its icy surface, which some scientists speculate could host extraterrestrial life. Now, for the first time, an astronomer has discovered evidence for persistent water vapour in the atmosphere of Europa.

Using a technique that recently resulted in the discovery of water vapour in the atmosphere of Jupiter’s moon Ganymede, an astronomer has found evidence of water in Europa’s trailing hemisphere — the portion of the moon that is always opposite to its direction of motion. The asymmetric distribution of water vapour was predicted by previous studies based on computer simulations, but had not previously been detected observationally.

“The observation of water vapour on Ganymede and on the trailing side of Europa advances our understanding of the atmospheres of icy moons,” commented Lorenz Roth of the KTH Royal Institute of Technology in Stockholm, Sweden, the author of this study. “The detection of a stable H2O abundance on Europa is surprising because the surface temperatures are so low.”

To make this discovery, Roth delved into archival Hubble datasets, selecting ultraviolet observations of Europa from 1999, 2012, 2014 and 2015 while the moon was at various orbital positions. These observations were all taken with one of Hubble’s most versatile instruments — the Space Telescope Imaging Spectrograph (STIS). These ultraviolet STIS observations allowed Roth to determine the abundance of oxygen — one of the constituents of water — in Europa’s atmosphere, and by interpreting the strength of emission at different wavelengths he was able to infer the presence of water vapour.

Previous observations of water vapour on Europa have been associated with transient plumes erupting through the ice, analogous to geysers here on Earth but more than 100 kilometres high. The phenomena seen in these plume studies were apparently transient inhomogeneities or blobs in the atmosphere. The new results, however, show similar amounts of water vapour to be present spread over a larger area in observations spanning from 1999 to 2015. This suggests the long-term presence of a water vapour atmosphere on Europa’s trailing hemisphere. Despite the presence of water vapour on Europa’s trailing hemisphere there is no indication of H2O on the leading hemisphere of Europa.

Space scientists working to understand these icy moons will soon be able to benefit from a close-up view. ESA’s JUpiter ICy moons Explorer (JUICE) mission is being prepared for a tour of Ganymede, Callisto and Europa, Jupiter’s three largest icy moons. JUICE is the first large-class mission in ESA's Cosmic Vision 2015–2025 programme and is expected to launch in 2022 and arrive at Jupiter in 2031. The probe will carry an advanced suite of instruments — the most powerful remote sensing payload ever flown to the outer Solar System — and will spend at least three years making detailed observations of the Jovian system. Europa will also be visited by a NASA mission, Europa Clipper, which will perform a series of flybys of the moon and investigate its habitability, as well as selecting a landing site for a future mission.

“This result lays the groundwork for future science based on upcoming missions to the Jovian moons,” concluded Roth. “The more we can understand about these icy moons before spacecraft like JUICE and Europa Clipper arrive, the better use we can make of our limited observing time within the Jovian system.”

This discovery and the insights from upcoming missions such as JUICE will improve our understanding of potentially habitable environments in the Solar System. Understanding the formation and evolution of Jupiter and its moons also helps astronomers gain insights into Jupiter-like exoplanets around other stars. Combined with observations from space telescopes such as the upcoming NASA/ESA/CSA James Webb Space Telescope, this could help astronomers determine if life could emerge in Jupiter-like exoplanetary systems elsewhere in the universe.

Credits: NASA, ESA, A. Simon (Goddard Space Flight Center), and M. H. Wong (University of California, Berkeley) and the OPAL team.; CC BY 4.0

New observations made with ESA’s X-ray XMM Newton telescope have revealed an “orphan cloud” – an isolated cloud in a galaxy cluster that is the first discovery of its kind.

A lot goes on in a galaxy cluster. There can be anything from tens to thousands of galaxies bound together by gravity. The galaxies themselves have a range of different properties, but typically contain systems with stars and planets, along with the material in between the stars – the interstellar medium. In between the galaxies is more material – tenuous hot gas known as the intercluster medium. And sometimes in all the chaos, some of the interstellar medium can get ripped out of a galaxy and get stranded in an isolated region of the cluster, as this new study reveals.

Unexpected discovery

Abell 1367, also known as the Leo Cluster, is a young cluster that contains around 70 galaxies and is located around 300 million light-years from Earth. In 2017, a small warm gas cloud of unknown origin was discovered in A1367 by the Subaru telescope in Japan. A follow-up X-ray survey to study other aspects of A1367 unexpectedly discovered X-rays emanating from this cloud, revealing that the cloud is actually bigger than the Milky Way.

This is the first time an intercluster clump has been observed in both X-rays and the light that comes from the warm gas. Since the orphan cloud is isolated and not associated with any galaxy, it has likely been floating in the space between galaxies for a long time, making its mere survival surprising.

The discovery of this orphan cloud was made by Chong Ge at the University of Alabama in Huntsville, and colleagues, and the study has been published in Monthly Notices of the Royal Astronomical Society.

Along with data from XMM-Newton and Subaru, Chong and colleagues also used the Multi Unit Spectroscopic Explorer (MUSE) on the Very Large Telescope (VLT) to observe the cluster in visible light.

The orphan cloud is the blue umbrella-shaped part of the image. It has been colour-coded to show the X-ray part of the cloud in blue, the warm gas in red, and the visible region in white shows some of the galaxies in the cluster. The part of the cloud that had been discovered in 2017 (in red) overlaps with the X-ray at the bottom of the cloud.

How the cloud became an orphan

It was previously thought that the distribution of material between galaxies is smooth, however more recent X-ray studies have revealed the presence of clumps in clusters. It was theorised that clumps of gas in the clusters were originally the gas that exists between stars in individual galaxies. The intercluster gas acts as a wind that is strong enough to pull the interstellar gas out of the galaxy as the galaxy is moving through the cluster. However, observations showing that intercluster clumps are originally stripped interstellar material have never been made until now. The observation of the warm gas in the clump provides the evidence to show that this orphan cloud originated within a galaxy. Interstellar material is much cooler than intercluster material, and the temperature of the orphan cloud matches that of interstellar gas. The researchers were also able to determine why the orphan cloud has survived for as long as it has. An isolated cloud would be expected to be ripped apart by instabilities caused by velocity and density differences. However, they found that a magnetic field in the cloud would be able to suppress these instabilities.

Searching for the parent galaxy

It is likely that the parent galaxy of the orphan cloud is a massive one as the mass of the X-ray gas in the orphan is substantial. It is possible that the parent might one day be discovered with future observations by following some breadcrumbs. For example, there are traces of the warm gas that extend beyond the orphan cloud that could be used to identify the parent with more data. There are other unsolved mysteries regarding the cloud that could be deciphered with more observations, such as mysterious offset between the brightest X-rays and the brightest light from the warm gas.

A closer inspection of this orphan will also further our understanding of the evolution of stripped interstellar medium at such a great distance from its parent galaxy and will provide a rare laboratory to study other things such as turbulence and heat conduction. This study paves the way for research on intercluster clumps, as future warm gas surveys can now be targeted to search for other orphan clouds.

Credits: Ge et al (2021)

This image, taken with the NASA/ESA Hubble Space Telescope, focuses on an object named UGC 695, which is located 30 million light-years away within the constellation Cetus (The Sea Monster), also known as The Whale.

UGC 695 is a low-surface-brightness (LSB) galaxy. These galaxies are so faint that their brightness is less than the background brightness of Earth’s atmosphere, which makes them tricky to observe. This low brightness is the result of the relatively small number of stars within them — most of the baryonic matter in these galaxies exists in the form of huge clouds of gas and dust. The stars are also distributed over a relatively large area.

LSB galaxies, like dwarf galaxies, have a high fraction of dark matter relative to the number of stars they contain. Astronomers still debate about how LSB galaxies formed in the first place.

Credits: ESA/Hubble & NASA, D. Calzetti; CC BY 4.0

The NASA/ESA Hubble Space Telescope has made its stunning yearly observations of the Solar System’s giant planets, to reveal atmospheric changes.

The NASA/ESA Hubble Space Telescope has completed its annual grand tour of the outer Solar System. This is the realm of the giant planets — Jupiter, Saturn, Uranus, and Neptune — extending as far as 30 times the distance between Earth and the Sun. Unlike the rocky terrestrial planets like Earth and Mars that huddle close to the Sun’s warmth, these far-flung worlds are mostly composed of chilly gaseous soups of hydrogen, helium, ammonia, and methane around a packed, intensely hot, compact core.

Though robotic spacecraft have sent back snapshots of their visits to these four monster planets over the past 50 years, their swirling, colourful atmospheres are constantly changing. Fulfilling the role of a weather forecaster, every time Hubble’s sharp cameras revisit these worlds there are new surprises, offering fresh insights into their wild weather, driven by still largely unknown dynamics taking place under the cloudtops.

Hubble’s snapshots of the outer planets reveal both extreme and subtle changes rapidly taking place in these distant worlds. Hubble’s sharp view gleans insights into the fascinating, dynamic weather patterns and seasons on these gas giants and allows astronomers to investigate the very similar — and very different — variables that contribute to their changing atmospheres.

Jupiter

This year’s Hubble observations of Jupiter track the ever-changing landscape of its turbulent atmosphere, where several new storms are making their mark and the planet’s equator has changed colour yet again.

Hubble’s 4 September photo puts the giant planet’s tumultuous atmosphere on full display. The planet’s equatorial zone is now a deep orange hue, which researchers are calling unusual. While the equator has departed from its traditional white or beige appearance for a few years now, scientists were surprised to find a deeper orange in Hubble’s recent imaging, when they were expecting the zone to cloud up again.

Just above the equator, researchers note the appearance of several new storms, nicknamed “barges.” These elongated, deeply structured red cells can be defined as cyclonic vortices, which vary in appearance. Whilst some of the storms are sharply defined and clear, others are fuzzy and hazy. This difference in appearance is caused by the physical properties within the clouds of the vortices.

Researchers also note that a feature dubbed “Red Spot Jr.” (Oval BA), below the Great Red Spot where Hubble just discovered winds are speeding up, is still a darker beige colour, and is joined by several additional white, cyclonic storms to the south.

Hubble’s crisp views of Jupiter in 2020 was one of the most popular ESA/Hubble photo releases to date.

Saturn

Hubble’s new look at Saturn on 7 September 2021 shows rapid and extreme colour changes in the bands in the planet’s northern hemisphere, where it is now early autumn. The bands have varied throughout Hubble observations in both 2019 and 2020. Hubble’s Saturn image catches the planet following the southern hemisphere’s winter, evident in the lingering blue-ish hue of the south pole.

Uranus

Hubble’s 25 October view of Uranus puts the planet’s bright northern polar hood in the spotlight. It’s springtime in the northern hemisphere and the increase in ultraviolet radiation from the Sun seems to be causing the polar region to brighten. Researchers aren’t sure why. It could be a change in the opacity of atmospheric methane haze, or some variation in the aerosol particles. Curiously, even as the atmospheric hood gets brighter, the sharp southernmost boundary remains at the same latitude. This has been constant over the past several years of Hubble observations of the planet. Perhaps some sort of jetstream is setting up a barrier at that latitude of 43 degrees.

Neptune

In observations taken on 7 September 2021, researchers found that Neptune’s dark spot, which was recently found to have reversed course from moving towards the equator, is still visible in this image, along with a darkened northern hemisphere. There is also a notable dark, elongated circle encompassing Neptune’s south pole. The blue colour of both Neptune and Uranus is a result of the absorption of red light by the planets’ methane-rich atmospheres.

Notes

These new Hubble images form part of yearly maps of the entire planet taken under the Outer Planets Atmospheres Legacy programme, or OPAL. The programme provides yearly Hubble global views of the outer planets to look for changes in their storms, winds, and clouds.

Note: The planets are not shown to scale in this image.

Credits: NASA, ESA, A. Simon (Goddard Space Flight Center), and M.H. Wong (University of California, Berkeley) and the OPAL team; CC BY 4.0

This remarkable spiral galaxy, known as NGC 4651, may look serene and peaceful as it swirls in the vast, silent emptiness of space, but don’t be fooled — it keeps a violent secret. It is believed that this galaxy consumed another smaller galaxy to become the large and beautiful spiral that we observe today.

Although only a telescope like the NASA/ESA Hubble Space Telescope, which captured this image, could give us a picture this clear, NGC 4651 can also be observed with an amateur telescope — so if you have a telescope at home and a star-gazing eye, look out for this glittering carnivorous spiral.

Credits: ESA/Hubble & NASA, D. Leonard; CC BY 4.0

Three views of the same supernova appear in the 2016 image on the left, taken by the NASA/ESA Hubble Space Telescope. But they're gone in the 2019 image. The distant supernova, named Requiem, is embedded in the giant galaxy cluster MACS J0138. The cluster is so massive that its powerful gravity bends and magnifies the light from the supernova, located in a galaxy far behind it. Called gravitational lensing, this phenomenon also splits the supernova's light into multiple mirror images, highlighted by the white circles in the 2016 image.

The multiply imaged supernova disappears in the 2019 image of the same cluster, at right. The snapshot, taken in 2019, helped astronomers confirm the object's pedigree. Supernovae explode and fade away over time. Researchers predict that a rerun of the same supernova will make an appearance in 2037. The predicted location of that fourth image is highlighted by the yellow circle at top left.

The light from Supernova Requiem needed an estimated 10 billion years for its journey, based on the distance of its host galaxy. The light that Hubble captured from the cluster, MACS J0138.0-2155, took about 4 billion years to reach Earth.

The images were taken in near-infrared light by Hubble's Wide Field Camera 3.

Credits: NASA, ESA, Steve A. Rodney (University of South Carolina), Gabriel Brammer (Cosmic Dawn Center/Niels Bohr Institute/University of Copenhagen), Joseph DePasquale (STScI); CC BY 4.0

Cassini ended its 13-year mission at Saturn on 15 September 2017 when it plunged into the gas giant's atmosphere, but the NASA/ESA Hubble Space Telescope is still keeping an eye on the ringed planet.

This is a composite image taken by Hubble on 6 June 2018 showing a fully-illuminated Saturn and its rings, along with six of its 62 known moons. The visible moons are (from left to right) Dione, Enceladus, Tethys, Janus, Epimetheus and Mimas (click here for an annotated version). Dione is the largest moon in the picture, with a diameter of 1123 km, compared to the smallest, oddly-shaped Epimetheus with a diameter around 116 km.

During Cassini’s mission, Enceladus was identified as one of the most intriguing moons, with the discovery of water vapour jets spewing from the surface implying the existence of a subsurface ocean. Icy moons with subsurface oceans could potentially offer the conditions to harbour life, and understanding their origins and properties are essential for furthering our knowledge of the Solar System. ESA's JUpiter ICy moons Explorer (Juice), due to launch in 2022, aims to continue this theme by studying Jupiter's ocean-bearing moons: Ganymede, Europa, and Callisto.

The Hubble image shown here was taken shortly before Saturn's opposition on 27 June, when the Sun, Earth and Saturn were aligned so that the Sun fully illuminated Saturn as seen from Earth. Saturn's closest approach to Earth occurs around the same time as opposition, which makes it appear brighter and larger and allows the planet to be imaged in greater detail.

In this image the planet’s rings are seen near their maximum tilt towards Earth. Towards the end of Cassini’s mission, the spacecraft made multiple dives through the gap between Saturn and its rings, gathering spectacular data in this previously unchartered territory.

The image also shows a hexagonal atmospheric feature around the north pole, with the remnants of a storm, seen as a string of bright clouds. The hexagon-shaped cloud phenomenon is a stable and persistent feature first seen by the Voyager 1 space probe when it flew past Saturn 1981. In a study published just last week, scientists using Cassini data collected between 2013 and 2017, as the planet approached northern summer, identified a hexagonal vortex above the cloud structure, showing there is still much to learn about the dynamics of Saturn’s atmosphere.

The Hubble observations making up this image were performed as part of the Outer Planet Atmospheres Legacy (OPAL) project, which uses Hubble to observe the outer planets to understand the dynamics and evolution of their complex atmospheres. This was the first time that Saturn was imaged as part of OPAL. This image was first published on 26 July.

Credits: NASA, ESA, A. Simon (GSFC) and the OPAL Team, and J. DePasquale (STScI); CC BY 4.0

This image from the NASA/ESA Hubble Space Telescope shows a pair of quasars (known as J0749+2255) that existed when the Universe was just 3 billion years old. They are embedded inside a pair of colliding galaxies. The quasars are separated by less than the size of a single galaxy. Quasars are powered by voracious, supermassive black holes blasting out ferocious fountains of energy as they engorge themselves on gas, dust, and anything else within their gravitational grasp. The black holes will eventually merge.

This discovery required the combined power of the NASA/ESA Hubble Space Telescope and the W.M. Keck Observatories in Hawaii. Multi-wavelength observations from the International Gemini Observatory in Hawaii, NSF's Karl G. Jansky Very Large Array in New Mexico, and NASA's Chandra X-ray Observatory also contributed to understanding the dynamic duo. And, ESA's Gaia space observatory helped identify this double quasar in the first place.

Hubble shows, unequivocally, that this is indeed a genuine pair of supermassive black holes, rather than two images of the same quasar created by a foreground gravitational lens. And, Hubble shows a tidal feature from the merging of two galaxies, where gravity distorts the shape of the galaxies forming two tails of stars.

However, Hubble's sharp resolution alone isn't good enough to go looking for these dual light beacons. Researchers enlisted Gaia, which launched in 2013, to pinpoint potential double-quasar candidates. Gaia measures the positions, distances, and motions of nearby celestial objects very precisely. But in a novel technique, it can be used to explore the distant universe. Gaia's huge database can be used to search for quasars that mimic the apparent motion of nearby stars. The quasars appear as single objects in the Gaia data because they are so close together. However, Gaia can pick up a subtle, unexpected "jiggle" that mimics an apparent change in position of some of the quasars it observes. In reality, the quasars aren't moving through space in any measurable way. Instead, their jiggle could be evidence of random fluctuations of light as each member of the quasar pair varies in brightness on timescales of days to months, depending on their black hole's feeding schedule. This alternating brightness between the quasar pair is similar to seeing a railroad crossing signal from a distance. As the lights on both sides of the stationary signal alternately flash, the sign gives the illusion of "jiggling."

Because Hubble peers into the distant past, this double quasar no longer exists. Over the intervening 10 billion years, their host galaxies have likely settled into a giant elliptical galaxy, like the ones seen in the local universe today. And, the quasars have merged to become a gargantuan, supermassive black hole at its centre. The nearby giant elliptical galaxy, M87, has a monstrous black hole weighing 6.5 billion times the mass of our Sun. Perhaps this black hole was grown from one or more galaxy mergers over the past billions of years.

[Image description: A close-up image of a dual quasar system is shown. They appear as two large, white blurry circles in the centre of the image.]

Credits: NASA, ESA, Yu-Ching Chen (UIUC), Hsiang-Chih Hwang (IAS), Nadia Zakamska (JHU), Yue Shen (UIUC)

The Copernicus Sentinel-2 mission takes us over northwest Lesotho – a small, land-locked country surrounded entirely by South Africa.

Known for its tall mountains and narrow valleys, Lesotho is the only nation in the world that lies completely above 1000 m in elevation. Lesotho has an area of just 30 000 sq km, around the same size as Belgium, and has a population of around two million.

Around 80% of the country’s population lives in rural areas and more than three quarters of these people are engaged in agriculture – mostly traditional, rainfed cereal production and extensive animal grazing. The country’s agricultural system faces a growing number of issues, including a small portion of the land deemed arable, as well as other climate-related vulnerabilities such as drought, floods and extreme temperatures occurring more frequently.

This composite image was created by combining three separate images from the near-infrared channel from the Copernicus Sentinel-2 mission over a period of nine months.

The first image, captured on 27 November 2020, is assigned to the red channel and represents the onset of the wet summer season; the second from 12 March 2021, represents green, and was captured towards the end of the wet season; and the third from 19 August 2021 covers the blue part of the spectrum, captured during the short, dry season.

All other colours visible in the image are different mixtures of red, green and blue, and vary according to the stage of vegetation growth. A distinct pattern emerges due to topographical differences in this mountainous landscape, such as altitude and slope, which influence local water availability.

Maseru, the capital and largest urban centre of Lesotho, lies directly on the Lesotho— South Africa border. The city is located on the left bank of the Caledon River, also known as the Mohokare River, visible in black.

The Copernicus Sentinel-2 mission is designed to provide images that can be used to distinguish between different crop types as well as data on numerous plant indices, such as leaf area, leaf chlorophyll and leaf water. The mission’s revisit time of just five days, along with the mission’s range of spectral bands, mean that changes in plant health and growth can be more easily monitored.

This image is also featured on the Earth from Space video programme.

Credits: contains modified Copernicus Sentinel data (2020-21), processed by ESA, CC BY-SA 3.0 IGO

NASA’s Orion spacecraft, powered by ESA’s European Service Module, shares a stunning new take on ‘Earth rise’ following the return powered flyby of the Moon.

This image was taken on 5 December, flight day 20, after the spacecraft completed a 3 minute 27 second burn to swing around the Moon and back to Earth.

Just before the burn, Orion made its second and final close approach to the Moon at 17:43 CET (16:43 GMT), passing 130 km above the lunar surface. 

The burn, which used the European Service Module’s main engine, changed the velocity of the spacecraft by about 1054 km/h. It was the final major engine burn of the Artemis I mission. 

Orion is due to splashdown in the Pacific Ocean on 11 December to complete the 25-day Artemis I mission.

“Orion is heading home!” said NASA administrator Bill Nelson. “The lunar flyby enabled the spacecraft to harness the Moon’s gravity and slingshot it back toward Earth for splashdown. Next up, reentry!”

Sadly, but necessarily, the European Service Module’s contribution to Artemis ends 40 minutes before splashdown. Together with the Crew Module Adapter these elements of the Orion spacecraft will detach from the Crew Module and burn up harmlessly in the atmosphere, leaving Orion on its own for the last crucial minutes to splashdown.

Find Artemis I mission updates and flight day logs on ESA’s Orion blog.

Credits: NASA

n mid-July the NASA/ESA Hubble Space Telescope observed Mars, only 13 days before the planet made its closest approach to Earth in 2018. While previous images showed detailed surface features of the planet, this new image is dominated by a gigantic sandstorm enshrouding the entire planet.

Each Martian year, moderately large dust storms cover continent-sized areas and last for weeks at a time. Global dust storms — lasting for weeks or months — tend to happen during the spring and summer in the southern hemisphere, when Mars is closest to the Sun and heating is at a maximum, leading to greater generation of winds.

While spacecraft orbiting Mars can study the storm’s behaviour at lower altitudes, Hubble observations allow astronomers to study changes in the higher atmosphere. The combined observations will help planetary scientists to build a better understanding of how these global storms arise.

Credits:

NASA, ESA, and STScI, CC BY 4.0

Spaceflight affects not only the body but also the mind. Viewing Earth from space day in and out for six months is bound to change a human’s perspective on Earth’s future in our Galaxy.

Living on Earth it is easy to find it rich, vast, and powerful. However, seeing Earth suspended in the void of space with just a thin protective layer shielding all its inhabitants from cosmic radiation, extreme temperatures, and flying projectiles, our mothership suddenly seems so fragile.

This cognitive shift is known as the overview effect that many astronauts report during and after spaceflight. It is an awareness brought on by countless hours of Earth viewing and the photographs taken, like this image captured by ESA astronaut Alexander Gerst from the International Space Station in November 2018, that shows just how thin Earth’s shield, our atmosphere, really is.

It is hard to measure the thickness of our atmosphere, as it becomes thinner with increasing altitude. Though there is no definitive boundary line between it and outer space, atmospheric effects become noticeable when spacecraft reenter Earth at an altitude of 120 km.

Regardless, it is the product of billions of years of biochemical change by the countless organisms able to survive on Earth thanks to this protective layer.

However, should life on Earth continue in its industrial-era tracks, the threats to our planet are internal. Unchecked human consumption of natural resources is causing global temperatures to rise. The resulting change in climate is wreaking havoc on natural habitats and leading to major weather events.

ESA’s Earth observation satellites, along with astronauts from the International Space Station, are witnesses to this global crisis and continue to provide us with data and imagery to inspire action.

This week representatives from almost 200 countries have gathered in Katowice, Poland for the 24th conference of the Parties (COP24) of the United Nations Framework Convention on Climate Change.

One of the most important tasks at the summit is to agree the course of action to implement the 2015 Paris Agreement – and, with the 2°C target now deemed not enough, to coordinate an international effort to halt warming at 1.5°C.

The meeting focuses on a triangle of nature, man and technology, and will investigate how they can be used to reduce climate change and mitigate its effects.

This will take determined and coordinated international effort to help protect our planet. In the meantime, astronauts will continue to share this overview to inspire action.

Credits: ESA/NASA

This image from the NASA/ESA Hubble Space Telescope shows the tattered remnant of a supernova — a titanic explosion marking the end of the life of a dying star. This object — known as DEM L249 — is thought to have been created by a Type 1a supernova during the death throes of a white dwarf. While white dwarfs are usually stable, they can slowly accrue matter if they are part of a binary star system. This accretion of matter continues until the white dwarf reaches a critical mass and undergoes a catastrophic supernova explosion, ejecting a vast amount of material into space in the process.

DEM L249 lies in the constellation Mensa and is within the Large Magellanic Cloud (LMC), a small satellite galaxy of the Milky Way only 160 000 light-years from Earth. The LMC is an ideal natural laboratory where astronomers can study the births, lives, and deaths of stars, as this region is nearby, oriented towards Earth, and contains relatively little light-absorbing interstellar dust. The data in this image were gathered by Hubble’s Wide Field Camera 3 instrument, and were obtained during a systematic search of the LMC for the surviving companions of white dwarf stars which have gone supernova.

Credits: ESA/Hubble & NASA, Y. Chu; CC BY 4.0

Artist's impression of Heracles landing on the Moon.

ESA is working with the Canadian and Japanese space agencies to prepare the Heracles robotic mission to the Moon in the mid-to-late-2020s. Using the Gateway as a halfway point, a robotic rover will scout the terrain in preparation for the future arrival of astronauts, and deliver lunar samples to Earth.

This mission offers the best and earliest chance to deliver Moon samples to Earth on NASA’s Orion spacecraft.

Goals also include testing new hardware, demonstrating technology and gaining experience in operations while strengthening international partnerships in exploration.

A small lander with a rover inside weighing around 1800 kg in total will land and be monitored by astronauts from the space gateway. An ascent module will take off from the surface and return to the gateway with samples taken by the rover.

Heracles will demonstrate these technologies and prove their value for humans. Later missions will include a pressurised rover driven by astronauts and an ascent module for the crew to return home.

Communications are key, with satellites providing high-speed networks to operate rovers from orbit, including feeding visuals from cameras, control signals to move the cameras, arms and wheels, and transmitting scientific data.

When the ascent module carrying the sample container arrives, the Gateway’s robotic arm will capture and berth it with the outpost’s airlock for unpacking and transfer of the container to Orion and subsequent flight to Earth with returning astronauts.

Heracles is an international programme to use the Gateway to the fullest and deliver samples to scientists on Earth using new technology that is more capable and lighter than previous missions.

Credits: ESA/ATG Medialab

Many people hope to catch a glimpse of these reddish-green swirls of colour floating in the polar skies. Few are as lucky as ESA astronaut Tim Peake, who captured this dazzling display of the aurora Australis from the International Space Station during his mission in 2016.

This stunning display of light splashed across the sky is a product of severe solar wind lashing against Earth’s protective magnetic shield.

But beauty often comes at a price, and the cost of the aurora, popularly known as the Northern or Southern Lights depending on the hemisphere, is constant surveillance of the Sun.

The giver of light and heat and a key enabler of life on our planet, our Sun is also a volatile ball of hot gas 1.3 million times larger than Earth. Though 4.6 billion years old, the Sun keeps on churning, emitting constant streams of electrons, protons and atomic particles, into space.

On its particularly active days, the Sun can throw out a Coronal Mass Ejection or CME, an outburst of colossal clouds of solar plasma that, if colossal enough, could have serious consequences for life on Earth. One such ejection produced a geomagnetic storm powerful enough to cause a nine-hour outage of electricity in Canada in 1989.

Changing conditions in space due to solar activity is known as space weather and some days it ‘rains’ electrons and protons. Geomagnetic storms can affect the vital systems on which our modern societies depend, such as satellites, communication networks or power grids.

So what is ESA doing about space weather?

We cannot control our Sun, but timely alerts – like those to be enabled by ESA’s future Lagrange solar warning mission – will allow civil authorities and commercial actors to take protective measures, helping minimise economic losses and avoid a disaster that could affect all of us. Advance warning of an oncoming solar storm would give operators of satellites, power grids and telecommunication systems time to take protective measures, sometimes as simple as turning off the devices.

Watching the Sun from a unique position in space, the Lagrange satellite will allow monitoring of the potentially hazardous sunspots and high-speed solar wind streams before they come into view from Earth, and detect solar events and their propagation toward our planet with higher accuracy than is possible today.

If you are lucky enough to glimpse the aurora, though beautiful and harmless, remember that they are the product of the cohabitation with an active star that can do real damage to daily life.

Credits: ESA/NASA

My tribute to "The Hubble Space Telescope", one of the most successful scientific endeavors that completely changed our view of the known Universe and our place within it.

Best viewed LARGE!

The image is not at full resolution, but is still best viewed as LARGE as possible. Zoom in and out by clicking on the image (in the gap under the Astrometry identification notes) and pan around. You can also view the image in lightbox mode by clicking HERE.

Original Resolution: 18 000px.

Current Resolution: 8 000px.

About M42, the Great Nebula in Orion:

M42 (NGC 1976) is a diffuse nebula situated in the Milky Way Galaxy, in the constellation of Orion. It is one of the brightest nebulae, and is visible to the naked eye in the night sky. M42 is located at a distance of 1,344 light-years from Earth, and is the closest region of massive star formation.

Why I like to "play around" with scientific data:

This Feynman quote sums it up...

"Feynman, that's pretty interesting, but what's the importance of it? Why are you doing it?'' ``Hah!'' I say. ``There's no importance whatsoever. I'm just doing it for the fun of it.'' - "Surely you're joking, Mr. Feynman'', by Richard P Feynman.

Data source:

The Hubble Legacy Archive (HLA).

The Space Telescope Science Institute (STScI).

hla.stsci.edu/hlaview.html

Processing:

Narrowband Monochrome FITS data in the HST Palette.

Processing and Linear workflow in PixInsight,

and finished in Photoshop.

Image processing by Martin Heigan.

Hubble Palette explanation:

www.astronomymark.com/hubble_palette.htm

Narrowband explanation:

www.swagastro.com/narrowband-information.html

My brief description of the Electromagnetic Spectrum of Light:

www.flickr.com/photos/martin_heigan/22278042895

Hubble Legacy Archive Credit:

Based on observations made with the NASA/ESA Hubble Space Telescope, and obtained from the Hubble Legacy Archive, which is a collaboration between the Space Telescope Science Institute (STScI/NASA), the Space Telescope European Coordinating Facility (ST-ECF/ESA) and the Canadian Astronomy Data Centre (CADC/NRC/CSA).

Flickr Explore:

Explore-2016-12-12

Martin Heigan

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Our galaxy, the Milky Way, is surrounded by about fifty dwarf galaxies. Most of these galaxies are only identifiable through telescopes and have been named after the constellation in which they appear on the sky (for example, Draco, Sculptor or Leo). However, the two most obvious dwarf galaxies are called the Large Magellanic Cloud (LMC) and the Small Magellanic Cloud (SMC), and these are easily visible to the unaided eye. Traditionally these dwarf galaxies have been thought of as satellites in orbit around the Milky Way for many billions of years. Now, however, new data from ESA’s Gaia spacecraft have shown that the majority of the dwarf galaxies are passing the Milky Way for the first time. This forces astronomers to reconsider the history of the Milky Way and how it formed, along with the nature and composition of the dwarf galaxies themselves.

More information.

Credits: ESA/Gaia/DPAC, CC BY-SA 3.0 IGO

A photo of the huge elliptical galaxy M87 [left] is compared to its three-dimensional shape as gleaned from meticulous observations made with the Hubble and Keck telescopes [right]. Because the galaxy is too far away for astronomers to employ stereoscopic vision, they instead followed the motion of stars around the center of M87, like bees around a hive. This created a three-dimensional view of how stars are distributed within the galaxy.

Astronomers picked one of the nearest ellipticals to Earth, M87, located 54 million light-years away in the heart of the vast Virgo cluster of galaxies. By following the motion of stars around the center of M87, like bees around a hive, they’ve measured that the galaxy is potato-shaped. It not only has a long and short axis, which defines an ellipse on a piece of graph paper, but they measured a third axis which helps define the three-dimensionality. The geometric term is: triaxial.

Credits: NASA, ESA, J. Olmsted (STScI), F. Summers (STScI)C. Ma (UC Berkeley); CC BY 4.0

An instrument destined for Jupiter orbit is checked after completing eight days of cryogenic radio-frequency testing at ESA’s ESTEC technical centre in the Netherlands.

The Sub-millimetre Wave Instrument of ESA’s Juice mission will survey the churning atmosphere of Jupiter and the scanty atmospheres of its Galilean moons.

Testing took place in ESA’s custom-built Low-temperature Near-field Terahertz chamber, or Lorentz.

The first chamber of its kind, the 2.8-m diameter Lorentz chamber can perform high-frequency radio-frequency testing in realistic space conditions, combining space-quality vacuum with ultra-low temperatures.

“The successful test of the flight hardware inside Lorentz, follows an intensive commissioning phase.” says ESA antenna engineer Paul Moseley. “This demonstration opens up a wide range of testing possibilities for missions to come.”

Meanwhile the flight model of the SWI instrument’s parent Juice spacecraft has itself reached the ESTEC Test Centre, in preparation for a month long thermal vacuum test campaign.

Credits: ESA-G. Porter

Space Science image of the week:

While one instrument of the NASA/ESA Hubble Space Telescope observed a pair of spiral galaxies for its 27th anniversary last month, another simultaneously observed a nearby patch of the sky to obtain this wide-field view.

These ‘parallel field’ observations increase the telescope’s productivity.

This parallel field shows an area of the sky awash largely with spiral galaxies like our Milky Way. Most of the prominent galaxies look different only because they are tilted at various orientations to our viewpoint – from edge-on to face-on. A few others are interacting or merging.

The image also shows a number of foreground stars in our own galaxy.

More image formats available here.

Credit: NASA, ESA & M. Mutchler (STScI), CC BY 4.0

Sand and dust stirred up by desert storms in north Africa have caused snow in eastern Europe to turn orange, transforming mountainous regions into Mars-like landscapes.

This Copernicus Sentinel-2A image of Libya captured on 22 March shows Saharan dust being blown northwards across the Mediterranean Sea. Lifted into the atmosphere, the dust was carried by the wind and pulled back down to the surface in rain and snow. It reached as far afield as Greece, Romania, Bulgaria and Russia. While the orange-tinted snow baffled skiers, meteorologists say this phenomenon occurs about every five years.

Credits: contains modified Copernicus Sentinel data (2018), processed by ESA ,CC BY-SA 3.0 IGO

This stunning spiral galaxy is Messier 100 in the constellation Coma Berenices, captured here by the NASA/ESA Hubble Space Telescope — not for the first time. Among Hubble’s most striking images of Messier 100 are a pair taken just over a month apart, before and after Servicing Mission 1, which took place 25 years ago in December 1993.

After Hubble was launched, the astronomers and engineers operating the telescope found that the images it returned were fuzzy, as if it were out of focus. In fact, that was exactly what was happening. Hubble’s primary mirror functions like a satellite dish; its curved surface reflects all the light falling on it to a single focal point. However, the mirror suffered from a defect known as a spherical aberration, meaning that the light striking the edges of the mirror was not travelling to the same point as the light from the centre. The result was blurry, unfocused images.

To correct this fault, a team of seven astronauts undertook the first Servicing Mission in December 1993. They installed a device named COSTAR (Corrective Optics Space Telescope Axial Replacement) on Hubble, which took account of this flaw of the mirror and allowed the scientific instruments to correct the images they received. The difference between the photos taken of Messier 100 before and after shows the remarkable effect this had, and the dramatic increase in image quality.

COSTAR was in place on Hubble until Servicing Mission 4, by which time all the original instruments had been replaced. All subsequent instrumentation had corrective optics built in.

This new image of Messier 100 taken with Hubble’s Wide Field Camera 3 (WFC3), demonstrates how much better the latest generation of instruments is compared to the ones installed in Hubble after its launch and after Servicing Mission 1.

Credits: NASA, ESA, CC BY 4.0

The Bering Strait is a sea passage that separates Russia and Alaska. It is usually covered with sea ice at this time of year – but as this image captured by the Copernicus Sentinel-1 mission on 7 March 2019 shows, it is virtually ice-free.

The Bering Strait is a narrow passage - around 80 km wide - connecting the Pacific and Arctic Oceans. The few patches of sea ice are shown in light-blue colours.

The extent of sea ice in the Bering Sea has dropped lower than it has been since written records began in 1850, and is most likely because of warm air and water temperatures. On average, the fluctuating sea ice in this region increases until early April, depending on wind and wave movement.

According to the National Snow & Ice Data Center, between 27 January to 3 March 2019, sea-ice extent decreased from 566 000 sq km to 193 000 sq km. Sea ice was also exceptionally low last year, but it has been reported that this March the extent of sea ice is the lowest in the 40-year satellite record.

To travel between Arctic and Pacific, marine traffic passes through the Bering Strait. Owing to the reduction of ice in the region, traffic has increased significantly.

The Copernicus Sentinel-1 satellites provide images to generate maps of sea-ice conditions for safe passage in the busy Arctic waters, as well as distinguish between thinner, more navigable first-year ice and thicker, more hazardous ice. Each satellite carries an advanced radar instrument to image Earth’s surface through cloud and rain, regardless of whether it is day or night.

Credits: contains modified Copernicus Sentinel data (2019), processed by ESA, CC BY-SA 3.0 IGO

The NASA/ESA Hubble Space Telescope has observed the supernova remnant named 1E 0102.2-7219. Researchers are using Hubble’s imagery of the remnant object to wind back the clock on the expanding remains of this exploded star in the hope of understanding the supernova event that caused it 1700 years ago.

The featured star that exploded long ago belongs to the Small Magellanic Cloud, a satellite galaxy of our Milky Way located roughly 200 000 light-years away. The doomed star left behind an expanding, gaseous corpse — a supernova remnant — known as 1E 0102.2-7219.

Because the gaseous knots in this supernova remnant are moving at different speeds and directions from the supernova explosion, those moving toward Earth are coloured blue in this composition and the ones moving away are shown in red. This new Hubble image shows these ribbons of gas speeding away from the explosion site at an average speed of 3.2 million kilometres per hour. At that speed, you could travel to the Moon and back in 15 minutes.

Researchers have studied the Hubble archive looking for visible-light images of the supernova remnant and they have analysed the data to calculate a more accurate estimate of the age and centre of the supernova blast.

According to their new estimates, light from this blast arrived at Earth 1700 years ago, during the decline of the Roman Empire. This supernova would only have been visible to inhabitants of Earth’s southern hemisphere. Unfortunately, there are no known records of this titanic event. Earlier studies proposed explosion dates of 2000 and 1000 years ago, but this new analysis is believed to be more robust.

To pinpoint when the explosion occurred, researchers studied the tadpole-shaped, oxygen-rich clumps of ejecta flung out by this supernova blast. Ionised oxygen is an excellent tracer because it glows brightest in visible light. By using Hubble’s powerful resolution to identify the 22 fastest moving ejecta clumps, or knots, the researchers determined that these targets were the least likely to have been slowed down by passage through interstellar material. They then traced the knots’ motion backward until the ejecta coalesced at one point, identifying the explosion site. Once that was known, they could calculate how long it took the speedy knots to travel from the explosion centre to their current location.

Hubble also measured the speed of a suspected neutron star — the crushed core of the doomed star — that was ejected from the blast. Based on the researchers’ estimates, it must be moving at more than 3 million kilometres per hour from the centre of the explosion to have arrived at its current position. The suspected neutron star was identified in observations with the European Southern Observatory’s Very Large Telescope in Chile, in combination with data from NASA’s Chandra X-ray Observatory.

Credits: NASA, ESA, and J. Banovetz and D. Milisavljevic (Purdue University); CC BY 4.0

The bright star at the centre of NGC 3132, while prominent when viewed by the NASA/ESA/CSA James Webb Telescope in near-infrared light, plays a supporting role in sculpting the surrounding nebula. A second star, barely visible at lower left along one of the bright star’s diffraction spikes, is the nebula’s source. It has ejected at least eight layers of gas and dust over thousands of years.

But the bright central star visible here has helped ‘stir the pot’, changing the shape of this planetary nebula’s highly intricate rings by creating turbulence. The pair of stars are locked in a tight orbit, which leads the dimmer star to spray ejected material in a range of directions as they orbit one another, resulting in these jagged rings.

Hundreds of straight, brightly-lit lines pierce through the rings of gas and dust. These ‘spotlights’ emanate from the bright star and stream through holes in the nebula like sunlight through gaps in a cloud.

But not all of the starlight can escape. The density of the central region, set off in teal, is reflected by how transparent or opaque it is. Areas that are a deeper teal indicate that the gas and dust are denser — and light is unable to break free.

Data from Webb’s Near-Infrared Camera (NIRCam) were used to make this extremely detailed image. It is teeming with scientific information — and research will begin following its release.

This is not only a crisp image of a planetary nebula — it also shows us objects in the vast expanse of space behind it. The transparent red sections of the planetary nebula — and all the areas outside it — are filled with distant galaxies.

Look for the bright angled line at the upper left. It is not starlight — it is a faraway galaxy seen edge-on. Distant spirals, of many shapes and colours, also dot the scene. Those that are farthest away — or are very dusty — are small and red.

NIRCam was built by a team at the University of Arizona and Lockheed Martin’s Advanced Technology Center.

Get the full array of Webb’s first images and spectra, including downloadable files, here.

Credits: NASA, ESA, CSA, STScI, Webb ERO Production Team

Mount Aso, the largest active volcano in Japan, is featured in this image captured on 1 January 2022 by the Copernicus Sentinel-2 mission.

Located in the Kumamoto Prefecture on the nation’s southernmost major island of Kyushu, Mount Aso rises to an elevation of 1592 m. The Aso Caldera is one of the largest calderas in the world, measuring around 120 km in circumference, 25 km from north to south and 18 km from east to west.

The caldera was formed during four major explosive eruptions from approximately 90 000 to 270 000 years ago. These produced voluminous pyroclastic flows and volcanic ash that covered much of Kyushu region and even extended to the nearby Yamaguchi Prefecture.

The caldera is surrounded by five peaks known collectively as Aso Gogaku: Nekodake, Takadake, Nakadake, Eboshidake, Kishimadake. Nakadake is the only active volcano at the centre of Mount Aso and is the main attraction in the region. The volcano goes through cycles of activity. At its calmest, the crater fills with a lime green lake which gently steams, but as activity increases, the lake boils off and disappears. The volcano has been erupting sporadically for decades, most recently in 2021, which has led to the number of visitors drop in recent years.

Not far from the crater lies Kusasenri: a vast grassland inside the mega crater of Eboshidake. Active just over 20 000 years ago, the crater has been filled with volcanic pumice from other eruptions, with magma still brewing a few kilometres below. Rainwater often accumulates on the plain forming temporary lakes. The pastures are used for cattle raising, dairy farming and horse riding.

One of the nearest populated cities is Aso, visible around 8 km north from the volcano, and has a population of around 26 000 people.

There are 110 active volcanoes in Japan, of which 47 are monitored closely as they have erupted recently or shown worrying signs including seismic activity, ground deformation or emissions of large amounts of smoke.

Satellite data can be used to detect the slight signs of change that may foretell an eruption. Once an eruption begins, optical and radar instruments can capture the various phenomena associated with it, including lava flows, mudslides, ground fissures and earthquakes. Atmospheric sensors on satellites can also identify the gases and aerosols released by the eruption, as well as quantify their wider environmental impact.

The image is also featured on the Earth from Space video programme.

Credits: contains modified Copernicus Sentinel data (2022), processed by ESA, CC BY-SA 3.0 IGO

Summer in the Northern hemisphere has arrived and with it the long, sunny days and hot, sticky nights.

Among barbecues and beach days is Asteroid Day, celebrated each year on 30 June, to raise awareness and educate people about small rocky bodies hurling through space that have the potential to do serious damage to our planet.

Though Earth is peppered with the pot marks of asteroid impacts across millennia, like the Aorounga impact crater in Chad, photographed here by ESA astronaut Tim Peake in 2016 from the International Space Station, we have not experienced a major impact since the Tunguska event in Siberia on 30 June 1908.

An official United Nations day of awareness, Asteroid Day encourages the public to join activities across 192 countries with scientists and specialists to talk asteroids.

For instance, do you know the difference between an asteroid and a meteorite?

A meteorite is a piece of debris that breaks off an asteroid and survives its descent through Earth’s atmosphere.

A meteorite is believed to be the cause of the Aorounga crater several hundred million years ago. Sediment buried the original crater but later eroded, forming these concentric rings.

It is not all bad. Asteroids are also a source of information about our Solar System and a potential new resources.

ESA is interested in asteroids for all these reasons. Over the past two decades, ESA has tracked and analysed asteroids that travel close to Earth, known as near-Earth objects or NEOs, of which there are an estimated 10 million larger than 10 m – the threshold above which damage on the ground could happen.

The answer to any potential threat is awareness and preparedness. ESA coordinates observatories and astronomers worldwide through its NEO Coordination Centre, located at ESA’s Centre for Earth Observation in Italy.

Building on this experience, ESA has developed a new type of automated telescope for night-sky surveys called ‘Flyeye’ and is proposing a network of these telescopes on Earth to monitor NEOs for approval by Europe’s space ministers at Space19+ this November.

Also being put forward as part of the Space Safety plans is Europe’s contribution to a pioneering international asteroid deflection experiment for planetary defence: the Hera mission, which is proposed for launch in October 2024.

On the fifth anniversary of Asteroid Day, join the main event via a 24-hour live broadcast streamed from Luxemburg City, in coordination with hundreds of other events all over Europe and the world. Talks will focus on the role of asteroids in the formation of our Solar System and the technological advances to detect, track and study them. Join the conversation online via #AsteroidDay2019.

Credits: ESA/NASA

Imaging Earth from space is a favourite pastime for astronauts on the International space Station. They can set their cameras to automatically snap photos while they work, but often make time to Earth-gaze and take photos of their own.

ESA astronaut Alexander Gerst snapped this photo of Europe at night in September, captioning it, “From space it's pretty clear that Europe belongs together.”

It is also pretty clear that Europe is very well lit at night, perhaps unnecessarily so.

Excessive artificial light is known as light pollution and it is often a problem in urban areas. Many meteor showers have gone unnoticed by urban populations and the average city dweller can make out very few stars and constellations in the synthetic glow.

A more serious consideration of light pollution is energy efficiency. As the world grapples with climate change and cleaner sources of energy, how that energy is put to use is a bright topic.

A citizen science project is hoping to address the problem of light pollution and energy efficiency in cities by creating a map of the world at night.

Cities at Night is an online platform that invites citizens to flip through the half a million photographs of Earth at night taken so far by astronauts from the Space Station to identify cities.

In this regard, humans are much more efficient than computers, which require complicated algorithms to categorise images. The human eye, on the other hand, can quickly differentiate a photograph of a city from that of stars.

The end result of Cities at Night will be map of Earth that is accessible to anyone. Researchers want to use the map to locate energy inefficiencies in urban cities to urge dimming of the lights. This would also reclaim some of the night sky for urban dwellers to enjoy.

Find out how you can help and improve your geography knowledge with the Cities at Night project. With a mind-boggling amount of data about our planet along with the availability of the latest digital technologies, citizen science projects such as these is just one way to help interpret the data and there are countless opportunities for innovation. ESA’s ɸ-week, running this week, explores how data and new technologies such as artificial intelligence and blockchain can benefit business, industry and science to bring benefits to all.

Credits: ESA/NASA

7 March 2022 marks the 20th anniversary of the Advanced Camera for Surveys (ACS) aboard the NASA/ESA Hubble Space Telescope. On 7 March 2002 astronauts installed the ACS during Hubble Servicing Mission 3B, also known as STS-109. With its wide field of view, sharp image quality, and high sensitivity, the ACS delivers many of Hubble’s most impressive images of deep space.

The ACS wavelength range extends from the ultraviolet, through the visible and out to the near-infrared. Its name, the Advanced Camera for Surveys, comes from its particular ability to map large areas of the sky in great detail. The ACS can also perform spectroscopy with a special optical tool called a grism.

Three subinstruments make up the ACS. The Wide Field Channel is a high-efficiency, wide-field, optical and near-infrared camera that is optimised to hunt for galaxies and galaxy clusters in the remote and ancient Universe, at a time when the cosmos was very young. The High Resolution Channel was designed to take extremely detailed (high resolution) pictures of the light from the centres of galaxies with massive black holes, though this is not currently operational, and the Solar Blind Channel blocks visible light to allow faint ultraviolet radiation to be discerned. Amongst other things, it can be used to study weather patterns on other planets and aurorae on Jupiter.

Learn more.

NASA, ESA; CC BY 4.0

For Asteroid Day, the Copernicus Sentinel-2 mission takes us over the Shoemaker Impact Structure (formerly known as Teague Ring) in Western Australia.

Located around 100 km northeast of the small town Wiluna, the Shoemaker Impact Structure was renamed in honour of Eugene Shoemaker, a planetary geologist and pioneer in impact crater studies.

The almost circular shape of the Shoemaker impact site, visible in the bottom-right of the image, is approximately 30 km in diameter and is defined by concentric rings formed in sedimentary rocks (seen in dark brown). The precise age of the impact is unknown, but is estimated to be between 1000 and 600 million years ago – making it Australia’s oldest impact crater.

This false-colour image was processed by selecting spectral bands that can be used for classifying geological features, allowing us to clearly identify the concentric rings in the image. The light blue areas are saline and ephemeral lakes including Nabberu, Teague, Shoemaker and other smaller ponds.

Asteroid Day, the UN-endorsed global awareness campaign is back on 30 June with an exciting 5-hour live broadcast from 18:00 CET. With the help of leading experts, Asteroid Day Co-founder Dr. Brian May and the most engaging voices in science communications from around the world, the five hour programme will bring the solar system’s smallest worlds to vivid life for audiences of all ages and backgrounds. For more information, visit ESA joins Asteroid Day for rocky live broadcast.

Credits: contains modified Copernicus Sentinel data (2021), processed by ESA, CC BY-SA 3.0 IGO

A dramatic triplet of galaxies takes centre stage in this latest Picture of the Week from the NASA/ESA Hubble Space Telescope, which captures a three-way gravitational tug-of-war between interacting galaxies. This system —known as Arp 195— is featured in the Atlas of Peculiar Galaxies, a list which showcases some of the weirder and more wonderful galaxies in the universe.

Observing time with the Hubble Space Telescope is extremely valuable, so astronomers don't want to waste a second. The schedule for Hubble observations is calculated using a computer algorithm which allows the spacecraft to occasionally gather bonus snapshots of data between longer observations. This image of the clashing triplet of galaxies in Arp 195 is one such snapshot. Extra observations such as these do more than provide spectacular images — they also help to identify promising targets to follow up with telescopes such as the upcoming NASA/ESA/CSA James Webb Space Telescope.

Credits: ESA/Hubble & NASA, J. Dalcanton; CC BY 4.0

For this Picture of the Week, the NASA/ESA Hubble Space Telescope turned its powerful eye towards an emission line galaxy called NGC 3749.

When astronomers explore the contents and constituent parts of a galaxy somewhere in the Universe, they use various techniques and tools. One of these is to spread out the incoming light from that galaxy into a spectrum and explore its properties. This is done in much the same way as a glass prism spreads white light into its constituent wavelengths to create a rainbow. By hunting for specific signs of emission from various elements within a galaxy’s spectrum of light — so-called emission lines — or, conversely, the signs of absorption from other elements — so-called absorption lines — astronomers can start to deduce what might be happening within.

If a galaxy’s spectrum shows many absorption lines and few emission lines, this suggests that its star-forming material has been depleted and that its stars are mainly old, while the opposite suggests it might be bursting with star formation and energetic stellar newborns. This technique known as spectroscopy, can tell us about a galaxy’s type and composition, the density and temperature of any emitting gas, the star formation rate, or how massive the galaxy’s central black hole might be.

While not all galaxies display strong emission lines, NGC 3749 does! It lies over 135 million light-years away, and is moderately luminous. The galaxy has been used a “control” in studies of especially active and luminous galaxies — those with centres known as active galactic nuclei, which emit copious amounts of intense radiation. In comparison to these active cousins, NGC 3749 is classified as inactive, and has no known signs of nuclear activity.

Credits: ESA/Hubble & NASA, D. Rosario et al.; CC BY 4.0

ESA’s XMM-Newton has X-rayed this beautiful cosmic creature, known as the Manatee Nebula, pinning down the location of unusual particle acceleration in its ‘head’.

The Manatee Nebula, or W50, is thought to be a large supernova remnant created when a giant star exploded around 30 000 years ago, flinging its shells of gases out across the sky. It is one of the largest such features known, spanning the equivalent size of four full Moons.

Unusually for a supernova remnant, a black hole remains in its core. This central ‘microquasar’, known as SS 433, emits powerful jets of particles travelling at speeds close to a quarter the speed of light that punch through the gassy shells, creating the double-lobed shape.

SS 433 is identified by the red dot in the middle of the image. The X-ray data acquired by XMM-Newton are represented in yellow (soft X-rays), magenta (medium energy X-rays) and cyan (hard X-ray emission), while red is radio and green optical wavelengths imaged by the Very Large Array and the Skinakas Observatory in Greece, respectively. NASA NuSTAR and Chandra data were also used for the study (not shown in this image).

The nebula attracted attention in 2018 when the High-Altitude Water Cherenkov Observatory, which is sensitive to very high energy gamma-ray photons, revealed the presence of highly energetic particles (hundreds of tera electron volts), but could not pinpoint from where within the Manatee the particles were originating.

XMM-Newton was crucial in homing in on the region of particle acceleration in the X-ray jet blasting from the Manatee’s head, which begins about 100 light years away from the microquasar (represented by the magneta and cyan colours towards the left side SS 433) and extends to approximately 300 light years (coinciding with the radio ‘ear’ where the shock terminates).

Samar Safi-Harb of the University of Manitoba, Canada, who led the study, says “thanks to the new XMM-Newton data, supplemented with NuSTAR and Chandra data, we believe the particles are getting accelerated to very high energies in the head of the Manatee through an unusually energetic particle acceleration process. The black hole outflow likely made its way there and has been re-energized to high-energy radiation at that location, perhaps due to shock waves in the expanding gas clouds and enhanced magnetic fields.”

The nebula acts as a nearby laboratory for exploring a wide range of astrophysical phenomena associated with the outflows of many galactic and extragalactic sources and will be subject to further investigation. Furthermore, follow-up studies by ESA’s future Athena X-ray observatory will provide even more sensitive details about the inner workings of this curious cosmic Manatee.

The paper Hard X-ray emission from the eastern jet of SS 433 powering the W50 ‘Manatee’ nebula: Evidence for particle re-acceleration has been accepted for publication in the Astrophysical Journal, and is also available via arXiv.

Credits: S. Safi-Harb et al (2022)

The NASA/ESA/CSA James Webb Space Telescope has captured one of the first medium-deep wide-field images of the cosmos, featuring a region of the sky known as the North Ecliptic Pole. The image, which accompanies a paper published in the Astronomical Journal, is from the Prime Extragalactic Areas for Reionization and Lensing Science (PEARLS) GTO program.

“Medium-deep” refers to the faintest objects that can be seen in this image, which are about 29th magnitude (1 billion times fainter than what can be seen with the unaided eye), while “wide-field” refers to the total area that will be covered by the program, about one-twelfth the area of the full moon. The image is composed of eight different colors of near-infrared light captured by Webb’s Near-Infrared Camera (NIRCam), augmented with three colors of ultraviolet and visible light from the NASA/ESA Hubble Space Telescope. This beautiful color image unveils in unprecedented detail and to exquisite depth a universe full of galaxies to the furthest reaches, many of which were previously unseen by Hubble or the largest ground-based telescopes, as well as an assortment of stars within our own Milky Way galaxy. The NIRCam observations will be combined with spectra obtained with Webb’s Near-Infrared Imager and Slitless Spectrograph (NIRISS), allowing the team to search for faint objects with spectral emission lines, which can be used to estimate their distances more accurately.

​​A swath of sky measuring 2% of the area covered by the full moon was imaged here with NIRCam instrument in eight filters and with Hubble’s Advanced Camera for Surveys (ACS) and Wide-Field Camera 3 (WFC3) in three filters that together span the 0.25 – 5-micron wavelength range. This image represents a portion of the full PEARLS field, which will be about four times larger. Thousands of galaxies over an enormous range in distance and time are seen in exquisite detail, many for the first time. Light from the most distant galaxies has traveled almost 13.5 billion years to reach us. Because this image is a combination of multiple exposures, some stars show additional diffraction spikes.

This representative-color image was created using Hubble filters F275W (purple), F435W (blue), and F606W (blue); and Webb filters F090W (cyan), F115W (green), F150W (green), F200W (green), F277W (yellow), F356W (yellow), F410M (orange), and F444W (red).

[Image Description: This image shows a medium-deep field of countless galaxies that appear throughout the field. Callouts are used to highlight three specific galaxies.]

Credits: NASA, ESA, CSA, A. Pagan (STScI) & R. Jansen (ASU); CC BY 4.0

This Picture of the Week, taken by the NASA/ESA Hubble Space Telescope, shows a close-up view of a galaxy named NGC 2770. NGC 2770 is intriguing, as over time it has hosted four different observed supernovae (not visible here).

Supernovae form in a few different ways, but always involve a dying star. These stars become unbalanced, lose control, and explode violently, briefly shining as brightly as an entire galaxy before slowly fading away.

One of the four supernovae observed within this galaxy, SN 2015bh, is especially interesting. This particular supernova initially had its identity called into question. When it was first discovered in 2015, astronomers classified SN 2015bh as a supernova imposter, believing it to be not an exploding star but simply an unpredictable outburst from a massive star in its final phase of life. Thankfully, astronomers eventually discovered the truth and the object was given its correct classification as a Type II supernova, resulting from the death of a star between eight and 50 times the mass of the Sun.

Credits: ESA/Hubble & NASA, A. Filippenko; CC BY 4.0

On 10 December, ESA’s XMM-Newton X-ray space observatory is celebrating its 20th launch anniversary. In those two decades, the observatory has supplied a constant stream of outstanding science. One area that the mission has excelled in is the science of black holes, having had a profound effect on our understanding of these cosmic enigmas.

Black holes are celestial objects so dense that nothing, not even light, can escape their pull. In this artist’s impression, the weird shapes of light around the black hole are what computer simulations predict will happen in the vicinity of its intense gravitational field.

Although neither XMM-Newton nor any other telescope can actually see black holes in this detail, the mission’s data and observations have provided a great source of information about these mysterious gravitational traps. In particular, XMM-Newton has been particularly good at isolating the X-rays given out by high-temperature, ionised atoms of iron as they swirl towards doom in the black hole.

The X-rays given out from the iron contain information about the geometry and dynamics of the black hole. In 2013, XMM-Newton was used to measure such emission in order to study the rotation rate of the supermassive black hole at the centre of the spiral galaxy NGC 1365.

Supermassive black holes, with masses between millions and billions of times the mass of our Sun, are thought to lurk in the centre of almost every large galaxy in the Universe. Their rotation rate is important because it can give away important details about the history of their host galaxy.

A fast rotating black hole is fed by a uniform stream of matter falling together, or by galaxies merging with one another, whereas a slowly rotating black hole is buffeted from all sides by small clumps of matter hitting it. In the case of NGC 1365, XMM-Newton showed that the black hole was rotating quickly and so the galaxy probably grew steadily over time, or merged with others.

More recently, XMM-Newton discovered mysterious flashes from the black hole at the centre of another galaxy called GSN 069. These flares took place every nine hours or so, raising the brightness of the X-ray emission by a factor of 100. These eruptions are thought to be coming from the matter caught in the black hole’s gravitational grip or from a less massive black hole circling the more massive one.

As XMM-Newton continues into its third decade, black holes and the galaxies they are found in will continue to be a priority target.

More about XMM-Newton’s first two decades in space:

XMM-Newton at 20: The fascinating X-ray Universe

XMM-Newton at 20: The large-scale Universe

XMM-Newton at 20: Taking care of the science operations

More about XMM-Newton

Credits: ESA/XMM-Newton/I. de la Calle

One of four partial solar eclipses observed by Proba-2 on 2 July from its viewpoint in space. Click here to watch a movie.

The image was taken by Proba-2’s SWAP imager, which images the Sun in ultraviolet light revealing the turbulent nature of the Sun's surface and corona – the Sun's extended atmosphere – stretching into space.

In this image a lot of bright dots and streaks can be seen. This is because the satellite was passing through the South Atlantic Anomaly. In this region the spacecraft is exposed to higher levels of radiation, with an increased flux of energetic particles falling on the satellite's detector.

Credits: ESA/Royal Observatory of Belgium

The densely packed globular cluster NGC 6325 glistens in this image from the NASA/ESA Hubble Space Telescope. This concentrated group of stars lies around 26 000 light years from Earth in the constellation Ophiuchus.

Globular clusters like NGC 6325 are tightly bound collections of stars with anywhere from tens of thousands to millions of members. They can be found in all types of galaxies, and act as natural laboratories for astronomers studying star formation. This is because the constituent stars of globular clusters tend to form at roughly the same time and with similar initial composition, meaning that astronomers can use them to fine-tune their theories of how stars evolve.

Astronomers inspected this particular cluster not to understand star formation, but to search for a hidden monster. Though it might look peaceful, astronomers suspect this cluster could contain an intermediate-mass black hole that is subtly affecting the motion of surrounding stars. Previous research found that the distribution of stars in some highly concentrated globular clusters — those with stars packed relatively tightly together — was slightly different from what astronomers expected.

This discrepancy suggested that at least some of these densely packed globular clusters — including perhaps NGC 6325 — could have a black hole lurking at the centre. To explore this hypothesis further, astronomers turned to Hubble’s Wide Field Camera 3 to observe a larger sample of densely populated globular clusters, which included this star-studded image of NGC 6325. Additional data from Hubble’s Advanced Camera for Surveys were also incorporated into this image.

[Image Description: A dense cluster of bright stars. The core of the cluster is to the left and has a distinct group of blue stars. Surrounding the core are a multitude of stars in warmer colours. These stars are very numerous near the core and become more and more sparse, and more small and distant, out to the sides of the image. A few larger stars also stand in the foreground near the edges of the image.]

Credits: ESA/Hubble & NASA, E. Noyola, R. Cohen; CC BY 4.0

The pair of strange, luminescent creatures at play in this image are actually galaxies — realms of millions upon millions of stars.

This galactic duo is known as UGC 2369. The galaxies are interacting, meaning that their mutual gravitational attraction is pulling them closer and closer together and distorting their shapes in the process. A tenuous bridge of gas, dust, and stars can be seen connecting the two galaxies,, during which they pulled material out into space across the diminishing divide between them.

Interaction with others is a common event in the history of most galaxies. For larger galaxies like the Milky Way, the majority of these interactions involve significantly smaller so-called dwarf galaxies. But every few aeons, a more momentous event can occur. For our home galaxy, the next big event will take place in about four billion years, when it will collide with its bigger neighbour, the Andromeda Galaxy. Over time, the two galaxies will likely merge into one — already nicknamed Milkomeda.

Credits: ESA/Hubble & NASA, A. Evans; CC BY 4.0

Retro meets retrofit: The Novespace Air Zero G aircraft is seen here next to Douglas the 1962 VW Transporter. The two are in Paderborn, Germany for the 76th ESA Parabolic Flight Campaign.

The refitted A310 Air Zero G aircraft flies in parabolas that offer teams from various research institutes and universities altered states of gravity to perform experiments and technology demonstrations. Experiments span many disciplines including complex fluidics and human physiology, and this campaign is no exception.

Running from 25 June to 1 July, the 76th campaign features an experiment studying the effect of gravity on hydrodynamics to better protect spacecraft and science instruments from the temperature fluctuations in space; a study on how immune cells flow under the stress of spaceflight; an experiment studying spinal stiffness under microgravity to mitigate lumbar pain for both astronauts and patients on Earth, to name a few.

A typical parabolic flight campaign involves three flights and requires a week of on-site preparation. Each flight offers 31 periods of weightlessness. The aircraft can also fly in arcs that provide lunar or martian gravity levels by adjusting the angle of attack of the wings. Each flight of this particular campaign will split the gravity states, flying one third of parabolas at martian-G, one third at lunar-G, and one third at zero-G.

The aircraft flies close to maximum speed and pulls the nose up to a 45° angle, then cuts the power to fall over the top of the curve. Whilst falling freely the passengers and experiments experience around 20 seconds of microgravity, until the plane is angled 45° nose-down, before pulling out of the dive to level off with normal flight.

These “pull up” and “pull out” manoeuvres before and after the weightless period increase gravity inside the plane up to 2g, but that is just part of the ride, repeated every three minutes for almost two hours.

The campaign is the fourth to take place under Covid-19 restrictions. Despite measures loosening across Europe, participants and coordinators adapted to safety measures: PCR tests were required to enter Germany, as well as rapid antigen or RT LAMP tests each day for every participant. Facilities on the ground as well as on board are adapted to allow for social distancing and cleanliness requirements. Surgical masks are worn at all times, and movement is restricted during the flights.

University students can also take part in a parabolic flight campaign thanks to the ESA Education Office’s Fly Your Thesis! programme. Masters and PhD students can propose their experiment, and upon selection, will be supported in preparing their experiment for the campaign by ESA Academy, ESA and Novespace experts. The 2022 Call for Proposals is now open.

Credits: ESA-N. Melville

ESA astronaut Alexander Gerst took this image of Hurriacane Florence on 12 September 2018, 400 km high from the International Space Station. He commented:

"Watch out, America! Hurricane Florence is so enormous, we could only capture her with a super wide angle lens from the International Space Station, 400 km directly above the eye. Get prepared on the East Coast, this is a no-kidding nightmare coming for you."

Alexander is on his second six-month Space Station mission. Follow him and the Horizons mission on social media on his website and on his blog.

Credits: ESA/NASA–A. Gerst

Space Science image of the week:

Now being fitted with its state-of-the-art instruments, ESA’s Solar Orbiter is set to provide new views of our star, in particular providing close-up observations of the Sun’s poles.

Following its launch in February 2019 and three-year journey using gravity swingbys at Earth and Venus, Solar Orbiter will operate from an elliptical orbit around the Sun. At its closest it will approach our star within 42 million kilometres, closer than planet Mercury.

An artist’s impression of Solar Orbiter in front of the stormy Sun is depicted here. The image of the Sun is based on one taken by NASA’s Solar Dynamics Observatory. It captures the beginning of a solar eruption that took place on 7 June 2011. At lower right, dark filaments of plasma arc away from the Sun. During this particular event, it watched the plasma lift off, then rain back down to create ‘hot spots’ that glowed in ultraviolet light.

Solar Orbiter’s over-arching mission goals are to examine how the Sun creates and controls the heliosphere, the extended atmosphere of the Sun in which we reside, and the effects of solar activity on it. The spacecraft will combine in situ and remote sensing observations close to the Sun to gain new information about solar activity and how eruptions produce energetic particles, what drives the solar wind and the coronal magnetic field, and how the Sun’s internal dynamo works.

Its 10 scientific instruments are in the final stages of being added to the spacecraft before extensive tests to prepare it for the 2019 launch from Cape Canaveral, USA.

Solar Orbiter is an ESA-led mission with NASA participation.

Credit: ESA/ATG medialab; Sun: NASA/SDO/ P. Testa (CfA)

Located around 5000 light-years away in the constellation of Cygnus (The Swan), Abell 78 is an unusual type of planetary nebula.

After exhausting the nuclear fuel in their cores, stars with a mass of around 0.8 to 8 times the mass of our Sun collapse to form dense and hot white dwarf stars. As this process occurs, the dying star will throw off its outer layers of material, forming an elaborate cloud of gas and dust known as a planetary nebula. This phenomenon is not uncommon, and planetary nebulae are a popular focus for astrophotographers because of their often beautiful and complex shapes. However, a few like Abell 78 are the result of a so-called “born again” star.

Although the core of the star has stopped burning hydrogen and helium, a thermonuclear runaway at its surface ejects material at high speeds. This ejecta shocks and sweeps up the material of the old nebula, producing the filaments and irregular shell around the central star seen in this Picture of the Week, which features data from Hubble’s Wide Field Camera 3 and PANSTARSS.

Credits: ESA/Hubble & NASA, M. Guerrero; CC BY 4.0

Acknowledgement: Judy Schmidt

The stars are in constant motion. To the human eye this movement – known as proper motion – is imperceptible, but Gaia is measuring it with more and more precision. The trails on this image show how 40 000 stars, all located within 100 parsecs (326 light years) of the Solar System, will move across the sky in the next 400 thousand years. These proper motions are released as part of the Gaia Early Data Release 3 (Gaia EDR3). They are twice as precise as the proper motions released in the previous Gaia DR2. The increase in precision is because Gaia has now measured the stars more times and over a longer interval of time. This represents a major improvement in Gaia EDR3 with respect to Gaia DR2.

Read more

Credits: ESA/Gaia/DPAC; CC BY-SA 3.0 IGO. Acknowledgement: A. Brown, S. Jordan, T. Roegiers, X. Luri, E. Masana, T. Prusti and A. Moitinho.

This observation from the NASA/ESA/CSA James Webb Space Telescope features the massive galaxy cluster RX J2129. Due to Gravitational lensing, this observation contains three different images of the same supernova-hosting galaxy. Gravitational lensing occurs when a massive celestial body causes a sufficient curvature of spacetime to bend the path of light travelling past or through it, almost like a vast lens. In this case, the lens is the galaxy cluster RX J2129, located around 3.2 billion light-years from Earth in the constellation Aquarius. Gravitational lensing can cause background objects to appear strangely distorted, as can be seen by the concentric arcs of light in the upper right of this image.

Astronomers discovered the supernova in the triply-lensed background galaxy using observations from the NASA/ESA Hubble Space Telescope, and they suspected that they had found a very distant Type Ia supernova. These supernovae always produce a fairly consistent luminosity — at the same distance, one looks as bright as any other — which makes them particularly helpful to astronomers. As their distance from Earth is proportional to how dim they appear in the night sky, objects with known brightness can be used as 'standard candles' to measure astronomical distances.

The almost uniform luminosity of a Type Ia supernova could also allow astronomers to understand how strongly the galaxy cluster RX J2129 is magnifying background objects, and therefore how massive the galaxy cluster is. As well as distorting the images of background objects, gravitational lenses can cause distant objects to appear much brighter than they would otherwise. If the gravitational lens magnifies something with a known brightness, such as a Type Ia supernova, then astronomers can use this to measure the ‘prescription’ of the gravitational lens.

This observation was captured by Webb's Near-InfraRed Camera to measure the brightness of the lensed supernova. As part of the same programme, NIRSpec spectroscopy of the supernova was also obtained, which will allow comparison of this distant supernova to Type Ia supernovae in the nearby Universe. This is an important way to verify that one of astronomers’ tried-and-tested methods of measuring vast distances works as expected.

[Image description: Stars and galaxies, mostly reddish in colour, are scattered across a dark background. In the foreground upper-right corner, a large elliptical galaxy is surrounded by many smaller similar galaxies in a cluster. These galaxies have bright centres and a diffuse white glow around them. The large galaxy has distorted images and arcs around it.]

Credits: ESA/Webb, NASA & CSA, P. Kelly

After four months of darkness, the Sun finally rises on 11 August at Concordia research station in Antarctica. The crew are understandably reverent.

ESA-sponsored medical doctor Stijn Thoolen (left) and engineer Wenceslas Marie-Sainte (right) are part of the 12-member crew spending an entire year at Concordia. For nine months they are holding down the base in one of the most isolated, confined and extreme environments on Earth, with no way in or out of the station.

They run experiments in human physiology and biology, atmospheric physics, meteorology and astronomy, among other disciplines, as well as maintain the base – one of only three to run year-round on the Antarctic Peninsula.

Four months of complete darkness is quite the challenge, one researchers are very interested in studying from a physiological and psychological point of view. From questionnaires to blood and stool samples, the crew are poked and prodded to understand how better to prepare humans for deep space travel.

Social dynamics are also of interest to researchers during the period of darkness. Stress brought on by lack of sunlight, changing sleep patterns, fatigue and moodiness can affect the group. The crew are especially encouraged to take on group activities and get creative to combat the isolation of the winter.

The first sunrise is always a remarkable moment, signalling the home stretch of their Antarctic residency. From now on the winter crew will start preparing for summer and the return of scientists that arrive for the warmer months starting in November. The base is cleaned thoroughly, machinery is serviced, tents are erected and heated, and the runway is cleared of snow. Extensive work is required to welcome the new arrivals back to the base at the end of the world.

Follow the adventures in science and socialisation at Concordia on the blog.

Credits: ESA/IPEV/PNRA–S. Thoolen

Fuerteventura and Lanzarote, part of the Canary Islands lying in the North Atlantic Ocean, are featured in this false-colour image captured by the Copernicus Sentinel-2 mission.

The Canary Islands are a group of ocean island volcanoes that were formed by volcanic activity millions of years ago. The Spanish region and archipelago is located around 100 km off the north coast of Africa and 1000 km from the Iberian Peninsula. The eight main islands are (in order of largest to smallest in area) Tenerife, Fuerteventura, Gran Canaria, Lanzarote, La Palma, La Gomera, El Hierro and La Graciosa. The archipelago also includes many smaller islands and islets.

Lanzarote, the easternmost of the Canary Islands, is visible in the top-right of the image. With over 150 000 inhabitants, it is the third most populous Canary Island, after Tenerife and Gran Canaria. It covers an area of 845 sq km, making it the fourth-largest of the islands in the archipelago.

Lanzarote has a long history of eruptions and is often referred to as the ‘Island of the 1000 volcanoes’, yet it is actually the least mountainous Canarian Island. The highest mountain is the volcano Peñas del Chache near Haría in the northern part of the island, which is 670 m above sea level. The Timanfaya National Park can be seen in the southwest part of the island and is entirely made up of volcanic soil.

Fuerteventura Island, the second largest of the Canaries, lies southwest of Lanzarote, across the Bocaina Strait. Its total area is 1731 sq km and the island is around 110 km long and no more than 30 km wide. Fuerteventura is the oldest island in the Canary Archipelago, having risen between 12 and 20 million years ago owing largely to volcanic activity.

The island is fairly flat and has a desert landscape of sand and stones as well as long beaches. The centre of the island is made up of a wide, elongated valley and, from north to south, is dissected by a series of extinct, eroded volcanoes. The west coast is dotted with rugged cliffs and small bays.

To the northeast of Fuerteventura, separated by the 15 m deep strait El Río, lies the island of Isla de Lobos. The only six sq km island is home to a 127 m high extinct volcano.

This image, also featured on the Earth from Space video programme, was captured on 24 September 2021 by Copernicus Sentinel-2 – a two-satellite mission to supply the coverage and data delivery needed for Europe’s Copernicus programme. The image was processed by selecting spectral bands that can be used for classifying geological features.

contains modified Copernicus Sentinel data (2021), processed by ESA, CC BY-SA 3.0 IGO