The galaxy NGC 4380 looks like a special effect straight out of a science fiction or fantasy film in this Hubble Picture of the Week, swirling like a gaping portal to another dimension.

In the grand scheme of things, though, the galaxy is actually quite ordinary. Spiral galaxies like NGC 4380 are one of the most common types of galaxy in the Universe. These colossal collections of stars, often numbering in the hundreds of billions, are shaped like a flat disc, sometimes with a rounded bulge in the centre. Graceful spiral arms outlined by dark lanes of dust wind around the bulging core, which glows brightly and has the highest concentration of stars in the galaxy.

Credits: ESA/Hubble & NASA, P. Erwin; CC BY 4.0

Keeping a launcher in flight connected with the ground is one of the toughest jobs an antenna can have. Having to contend with high temperatures, vibration and atmospheric slipstream is hard enough, but shifting atmospheric pressure levels as the launcher heads into the vacuum of space (and potentially back again) can risk dangerous electrical discharges called corona – being tested for here.

The antenna design being tested at ESA’s High Power Radio Frequency Laboratory in Valencia, Spain, is one of a quartet that is about to see service on Spain’s Miura 1 sub-orbital micro-launcher, developed by the PLD Space company. But the four antennas are also undergoing a separate test campaign to qualify them for wider future uses.

“There are four different antenna types in all, each being flown in pairs aboard Miura 1,” explains ESA antenna engineer Victoria Iza.

“One is a Global Navigation Satellite Signal antenna, using satellite navigation signals to track the launcher’s position; one is an S-band antenna to transmit telemetry plus C-band and UHF antennas that both serve the security system that will end the flight safely in case of malfunction, operating on a redundant basis.

“Built by Spain’s Anteral company, this quartet of conformal dielectric antennas – each roughly the size of a smartphone and made to fit around the hull of the upper stage – has already been qualified as part of the avionics bay of the Miura 1. But with the number of European small launchers increasing rapidly, supported by ESA’s Boost! programme, the potential is there for these antennas to find wider uses, so they are being put through a separate qualification programme.”

Taking place through ESA’s General Support Technology Programme, helping develop promising new products for space and the open market, the antennas are currently undergoing environmental testing including thermal vacuum where they are exposed to sustained vacuum and temperature extremes – and vibration tests.

These antennas have to sustain harsh thermomechanical environments during launch, orbital flight and eventual return to Earth, so the project has been supported on the ESA side by structures engineer Goncalo Rodrigues and thermal engineer Miguel Copano.

Key stress factors are vibrations propagating from the launch vehicle jet engines, shocks resulting from the fairing and stages separation and the extreme temperatures resulting from aerothermal fluxes and – once in orbit – alternating Sun and cold space exposure.

To check the antennas designs can not only survive but go on operating as intended, the team employed a combination of computer simulations and on-ground test facilities including electro-magnetic shakers, pyro-shock tables and thermal-vacuum chambers.

“Most of the testing has been carried out at the Public University of Navarra, UPNA, but ESA’s High Power Radio Frequency Lab was used for corona discharge testing,” adds Victoria.

“When a radio frequency antenna is surrounded by a vestigial amount of atmosphere – as when a launcher is either leaving or returning to a planetary atmosphere – then there is the potential for this air to become ionised by the radio signal, risking damaging lightning-like discharge.

“The antennas were placed in this glass container so that their surrounding air levels can be changed while the antennas are in operation; the glass does not impede the radio signals. Our full test campaign will conclude soon, hopefully helping the antennas to find fresh markets, not only for launchers – for instance, their demonstrated robustness means they could also be used aboard planetary landers.”

"For Anteral, the development of these antennas is key to our positioning in the small launcher market,” explains Fernando Teberio, Chief Technology Officer of Anteral.

Anteral CEO Itziar Maestrojuan notes: “Thanks to the support from ESA we have been able to fully qualify the antennas that will be used on Miura-1 and hopefully on many other launchers and different applications where reliability is a key parameter.”

Credits: Anteral

Antofagasta, a port city in northern Chile, is featured in this image captured by the Copernicus Sentinel-2 mission.

Located around 1000 km north of Santiago, Antofagasta is the capital of both the Antofagasta Province and Region. The Antofagasta province borders the El Loa and Tocopilla provinces to the north and the Pacific Ocean to the west.

The city stretches approximately 22 km along the coast, snuggled between the ocean and the arid mountains to the east. The largest city in northern Chile, Antofagasta has a population of around 400 000 people. The city’s early growth resulted from the discovery of nitrate deposits in 1866, while today the economy is mainly based on the exploitation of various minerals such as copper and sulphur.

In the right of the image, large, emerald green geometric shapes are visible and are most likely evaporation ponds used in mining operations. These bright colours are in stark contrast with the surrounding desert landscape, which is largely devoid of vegetation, making them easily identifiable from space.

The city of Antofagasta is also a communications centre on the Pan-American Highway, visible as distinctive black lines in the right of the image, and is also linked by rail to the mines, as well as Bolivia and Argentina.

Antofagasta is located within the Atacama Desert which is considered one of the driest places on Earth, as there are some parts of the desert where rainfall has never been recorded. Antofagasta typically has a cold desert climate with abundant sunshine, with January being its warmest month.

This image, captured on 6 January 2021, shows little cloud cover over the city and surrounding area but strong westerly winds have created distinct wave patterns over the ocean – visible all the way from space.

This image was captured by the Copernicus Sentinel-2 mission – a two-satellite mission to supply the coverage and data delivery needed for Europe’s Copernicus programme. Each satellite carries a high-resolution camera that images Earth’s surface in 13 spectral bands. Data from Sentinel-2 can help support ocean applications, monitor changes in urban expansion, land-cover change and agriculture monitoring.

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

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

The Colour and Stereo Surface Imaging System (CaSSIS) onboard the ExoMars Trace Gas Orbiter mission returned this image of an area in Melas Chasma, part of the vast Valles Marineris canyon system on Mars. Valles Marineris stretches for more than 4000 km across the planet’s surface, and plunges more than 7 km deep in places.

The section seen here is about 5 x 6 km in size. It is a colour infrared image (combining the NIR, PAN and BLU filters of CaSSIS), and emphasizes the spectral diversity of landforms and sediments on the surface. It shows details of a blocky deposit on the floor of Melas Chasma that is consistent with an eroded and exposed landslide deposit. Windblown ripples are abundant and interspersed between the blocks.

The CRISM spectrometer on NASA’s Mars Reconnaissance Orbiter revealed a variety of minerals and phases that correlate with the light-toned blocks seen here (for example: nontronite, jarosite, aluminium-rich clays, hydrated silica, and/or an acid-leached clay). The tan-coloured ripples likely contain ferric iron oxides that gives rise to this distinctive colour. There is also evidence of the past presence of water in this region. The bright-white layered materials imply the presence of a hydrated calcium sulphate (possibly gypsum), which is thought to have formed through the ponding and subsequent evaporation of water that may have once occupied portions of the Chasma floor.

The image was taken on 19 October 2020 and featured on the February 2021 cover of Nature Geoscience.

The ExoMars programme is a joint endeavour between ESA and Roscosmos.

Credits: ESA/Roscosmos/CaSSIS, CC BY-SA 3.0 IGO

This NASA/ESA Hubble Space Telescope image contains a veritable mix of different galaxies, some of which belong to the same larger structure: At the middle of the frame sits the galaxy cluster SDSS J1050+0017.

The gigantic mass of this cluster creates the fascinating phenomenon of strong gravitational lensing. The gravity of the cluster bends light coming from behind it in a similar way to how the base of a wine glass bends light. The effects of this lensing can be clearly seen as curved streaks forming a circular shape around the centre of the frame. Astronomers can use these distorted galaxies to calculate the mass of the cluster — including the mass of the dark matter within it — and to peer deeper into the Universe as otherwise possible. Gravitational lensing does not only distorts the views of galaxies, it also enlarge their appearance on the sky and magnifies their light.

Hubble has viewed gravitational lensing many times, and produced truly stunning images. Astronomers even set up a dedicated programme to study different galaxy clusters which show a great number of lensed galaxies: The Frontier Fields programme. This way some of the most distant galaxies in the Universe were found. With each additional cluster being observed some more distant galaxies are added to this list, slowly completing our picture of how galaxies looked and evolved in the early Universe.

Credits: ESA/Hubble & NASA, CC BY 4.0; Acknowledgement: Judy Schmidt

This delicate image showing the intricacies of interstellar bubbles and wisps reveals great turmoil in the W3/W4/W5 complex of molecular clouds and star-forming regions. It was taken by ESA’s Herschel Space Observatory, a trailblazing mission that observed the sky in far-infrared and submillimetre wavelengths between 2009 and 2013.

September has often been the month of memorable moments or milestones for Herschel.

When the satellite was still on Earth, it was in September 2005 that the assembled telescope its first tests.

September 2007 saw the mating of the mission’s ‘brain’ – the payload module with the instruments and the cryostat that would keep them at the required temperature, just above absolute zero – with its ‘heart’, or the service module, that would to keep the spacecraft going.

During the same month, scientists gathered to plan how to get the most of this extraordinary mission from the observing time that would be available.

Finally, the satellite was launched on 14 May 2009. A few months later, it was again in September that the first Herschel science observations were performed – a memorable moment for many astronomers across the world.

Eight years later, as the mission approaches retirement, ESA celebrates the marvellous science that it has achieved and takes stock of the legacy that Herschel leaves behind.

One of the areas where Herschel has made substantial contributions concerns the processes that lead to the formation of stars, surveying a large number of stellar nurseries like the W3/W4/W5 complex in this image.

Read more about Herschel’s unprecedented glimpse into the stellar cradles of our Galaxy and the giant strides that have been taken in our understanding of how stars and their planetary systems come to life.

Among many other exciting findings, Herschel’s observations have also traced the trail of water across the cosmos, and pieced together the evolution of galaxies throughout 14 billion years of the Universe’s history. Follow Herschel Week to read more about these fascinating discoveries and about the legacy that the mission leaves for the future generations of telescopes.

Join ESA to celebrate Herschel Week and share your memorable #HerschelMoments

Credit: ESA/Herschel/NASA/JPL-Caltech; acknowledgement: R. Hurt (JPL-Caltech), CC BY-SA 3.0 IGO

On Asteroid Day, the Copernicus Sentinel-2 mission takes us over the Roter Kamm impact crater in Namibia. The circular shape of the crater rim can be seen in the left of the image, just below the centre.

Zoom in to view this image at its full 10 m resolution.

The Roter Kamm impact crater is located in the Tsau ǁKhaeb National Park, also known as the Sperrgebiet, a diamond mining area in the Namib Desert, in southwest Namibia. According to geologists, the crater was formed by a meteorite around the size of a large vehicle that collided with Earth approximately 5 million years ago.

The crater has a diameter of 2.5 km and is around 130 m deep. It is clearly visible in the midst of the rust-red dunes, with its rims rising some 40 to 90 m above the surrounding plain. Its floors are covered by sand deposits at least 100 m thick.

Meteorites and asteroids have influenced Earth’s development, as seen by the millions of impact craters scarring our world. Each year on 30 June, the worldwide UN-sanctioned Asteroid Day takes place to raise awareness about asteroids and what can be done to protect Earth from possible impact. The day falls on the anniversary of the Tunguska event that took place on 30 June 1908 in Siberia, the most harmful known asteroid related event in recent history.

Over the last two decades, ESA has been performing detection and analysis of asteroids whose orbits bring them close to Earth, known as near-Earth objects (NEOs). There are an estimated 40 000 000 NEOs out there larger than 10 m – the threshold above which damage on the ground could happen.

ESA is also developing the Hera mission, which will be the first to test the effectiveness of asteroid deflection, as it flies to the Didymos binary system that will soon be impacted by NASA’s DART. If an asteroid is detected that is on collision course with Earth, these missions mean we will be more prepared to act.

Follow the latest asteroid news and updates today at 12:00 CEST on Asteroid Day TV. Hosted by award-winning science and space journalist Richard Hollingham, the programme will include features and discussions with leading asteroid experts.

ESA’s Asteroid Day programme is available in six languages, all available to replay

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

Chongqing, the largest municipality in China, is featured in this Copernicus Sentinel-2 image.

Covering an area of over 80 000 sq km, around the size of Austria, Chongqing is located in southwest-central China. Chongqing covers a large area crisscrossed by rivers and mountains. These are the Daba Mountains in the north, the Wu Mountains in the east, the Wuling Mountains in the southeast and the Dalou Mountains in the south.

The city of Chongqing, one of the most important economic centres in China, is known as a ‘mountain city’ owing to its rugged terrain and steep gorges. Chongqing is a major manufacturing and transportation centre, and has become the biggest automobile manufacturing base in China.

The city lies at the confluence of the Yangtze and Jialing rivers, where the clashing colours of the rivers meet. The Yangtze river is visible in brown in the right of the image, while the green waters of the Jialing can be seen in the left. The rivers make Chongqing China's biggest port city in the southwest region.

With a length of 6300 km, the Yangtze is the longest river in both China and Asia and the third longest river in the world. The Jialing River, rises in the Qin Mountains, and joins the Yangtze after a course of around 1190 km.

Copernicus Sentinel-2 is a two-satellite mission. Each satellite carries a high-resolution camera that images Earth’s surface in 13 spectral bands. The mission is mostly used to track changes in the way land is being used and to monitor the health of our vegetation.

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

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

The galaxy depicted in this Picture of the Week is a barred spiral known as NGC 7541, seen here as viewed by the NASA/ESA Hubble Space Telescope, in the constellation of Pisces (The Fishes).

A barred spiral is a galaxy with whirling, pinwheeling, spiral arms, and a bright centre that is intersected by a bar of gas and stars. This bar cuts directly through the galaxy’s central region, and is thought to invigorate the region somewhat, sparking activity and fuelling myriad processes that may otherwise have never occurred or have previously ground to a halt (star formation and active galactic nuclei being key examples). We think bars exist in up to two-thirds of all spiral galaxies, including our own home, the Milky Way.

NGC 7541 is actually observed to have a higher-than-usual star formation rate, adding weight to the theory that spiral bars act as stellar nurseries, corralling and funnelling inwards the material and fuel needed to create and nurture new baby stars. Along with its nearby companion NGC 7537, the galaxy makes up a pair of galaxies located about 110 million light-years away from us.

Credits: ESA/Hubble & NASA, A. Riess et al.; CC BY 4.0

This pair of NASA/ESA Hubble Space Telescope images of comet C/2019 Y4 (ATLAS), taken on April 20 and April 23, 2020, reveal the breakup of the solid nucleus of the comet. Hubble photos identify as many as 30 separate fragments. The comet was approximately 146 million kilometres from Earth when the images were taken. The comet may be a broken off piece of a larger comet that swung by the Sun 5,000 years ago.

The comet has been artificially colored in this view to enhance details for analysis.

In a new study using Hubble’s observations, astronomer Quanzhi Ye of the University of Maryland in College Park, reports that ATLAS is a broken-off piece of that ancient visitor from 5,000 years ago. This is because ATLAS follows the same orbital "railroad track" as that of a comet seen in 1844. This means the two comets are probably siblings from a parent comet that broke apart many centuries earlier. The link between the two comets was first noted by amateur astronomer Maik Meyer.

Credits: NASA, ESA, STScI, Quanzhi Ye (UMD), Alyssa Pagan (STScI); CC BY 4.0

Captured by the Copernicus Sentinel-3 mission on 30 July 2021, this image shows smoke billowing from several fires along the southern coast of Turkey. Turkey has been battling deadly wildfires since last week. Over the weekend, tourists and local residents had to be evacuated from Bodrum and Marmaris, with some fleeing by boat as the flames crept closer to the shoreline. Southeast Europe is currently experiencing extremely high temperatures. Greece is reported to be expecting an all-time European record today of 47°C. The heatwave, the result of a heat dome, has seen temperatures reach above 40°C in many areas, and meteorologists expect the weather will continue this week, making it the most severe heatwave since the 1980s.

Fires have also been raging in Spain, Italy and Greece, some of which have led to the Copernicus Emergency Mapping Service being triggered. The mapping service uses data from satellites to aid response to disasters such as wildfires and floods.

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

A glittering multitude of stars in the globular cluster Terzan 4 fill this image from the NASA/ESA Hubble Space Telescope. Globular clusters are collections of stars bound together by their mutual gravitational attraction, and can contain millions of individual stars. As this image shows, the heart of a globular cluster such as Terzan 4 is a densely packed, crowded field of stars — which makes for spectacular images!

The launch of Hubble in 1990 revolutionised the study of globular clusters. The individual stars in these dense crowds are almost impossible to distinguish from one another with ground-based telescopes, but can be picked apart using space telescopes. Astronomers have taken advantage of Hubble’s crystal-clear vision to study the stars making up globular clusters, as well as how these systems change over time.

This particular observation comes from astronomers using Hubble to explore Terzan 4 and other globular clusters to understand the shape, density, age, and structure of globular clusters close to the centre of the Milky Way. Unlike globular clusters elsewhere in the sky, these globular clusters have evaded detailed observation because of the clouds of gas and dust swirling around the galactic core. These clouds blot out starlight in a process that astronomers refer to as ‘extinction’, and complicate astronomical observations.

Astronomers took advantage of the sensitivity of two of Hubble’s instruments — the Advanced Camera for Surveys and Wide Field Camera 3 — to overcome the impact of extinction on Terzan 4. By combining Hubble imagery with sophisticated data processing, astronomers were able to determine the ages of galactic globular clusters to within a billion years — a relatively accurate measurement in astronomical terms!

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

Mississippi River, one of the longest rivers in North America, is featured in this multi-temporal radar image captured by the Copernicus Sentinel-1 mission.

The Mississippi River is one of the world’s major river systems in size, habitat diversity and biological productivity. The river flows 3766 km from its source at Lake Itasca through the centre of the continental United States to the Gulf of Mexico.

The area pictured here shows where the Mississippi straddles the states of Louisiana and Mississippi. The image combines three radar acquisitions from the Sentinel-1 mission taken 12 days apart to show changes in crop and land conditions over time. Bright colours in the image come from changes on the ground that have occurred between acquisitions.

Water bodies, including the Mississippi River, visible in the far right, and Catahoula Lake, in the far left, appear black as water surfaces reflect the radar signal away from the satellite. If we take a closer look, we can see cargo ships travelling along the Mississippi. Ships from 7 April 2022 appear in red, those from 19 April appear in green, and those from 1 May appear in blue.

White areas in the image indicate the various types of vegetation that surrounds the river, including the Kisatchie National Forest – the only national forest in Louisiana. The Mississippi is a classic example of a meandering alluvial river with its loops and curls along its path leaving behind meander scars, cutoffs and free-standing ‘oxbow lakes’.

The Mississippi River Basin is home to a variety of agricultural activity. Nutrient-rich soil from sediment deposits through the floodplain supports cropland close to the river and its tributaries. Rectangular fields in the image are cultivated land. The farming of cotton and soybean make up a significant portion of the areas economic production.

Sentinel-1A was the first satellite to be launched for Copernicus – the Earth observation component of the European Union’s space programme. Looking ahead, the upcoming Sentinel-1C satellite scheduled to lift off on ESA’s Vega-C rocket from Europe’s Spaceport in French Guiana in the first half of 2023, will continue the critical task of delivering key radar imagery for a wide range of services, applications and science.

The satellite is now at Thales Alenia Space’s Cannes plant on the French Riviera after it successfully completed all integration tests this summer in Rome, Italy. It will now undergo a final series of tests in Cannes, including radiofrequency performance checks in the facility’s anechoic chamber.

This 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

The spiral arms of the galaxy NGC 7038 wind languidly across this image from the NASA/ESA Hubble Space Telescope. NGC 7038 lies around 220 million light-years from Earth in the southern constellation Indus. This image portrays an especially rich and detailed view of a spiral galaxy, and exposes a huge number of distant stars and galaxies around it. That’s because it’s made from a combined 15 hours worth of Hubble time focused on NGC 7038 and collecting light. So much data indicates that this is a valuable target, and indeed, NGC 7038 has been particularly helpful to astronomers measuring distances at vast cosmic scales.

The distances to astronomical objects are determined using an interconnected chain of measurement techniques called the Cosmic Distance Ladder. Each rung in the ladder is calibrated by earlier steps, based on measurements of objects closer to us. This makes the accuracy of distances at the largest scales dependent on how accurately distances to nearby objects can be determined. Hubble inspected NGC 7038 with its Wide Field Camera 3 to calibrate two of the most common distance measurement techniques: type 1A supernovae and Cepheid variables.

One of Hubble's original science goals was to accurately establish distances to night-sky objects, and over its three decades of operation Hubble’s increasingly precise distance measurements have contributed to one of the most intriguing unsolved problems in astronomy. Distance measurements are used to derive a quantity known as the Hubble constant, which captures how fast the Universe is expanding. As astronomer’s measurements of the Hubble constant have become more precise, their value has become increasingly inconsistent with the value of the Hubble Constant derived from observations of the Big Bang’s afterglow. Astronomers have been unable to explain the mismatch between the two values of the Hubble constant, which suggests that a new discovery in cosmology is waiting to be made.

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

Clustered at the centre of this image are six luminous spots of light, four of them forming a circle around a central pair. Appearances can be deceiving, however, as this formation is not composed of six individual galaxies, but only three: to be precise, a pair of galaxies and one distant quasar. Hubble data also indicates that there is a seventh spot of light in the very center, which is a rare fifth image of the distant quasar. This rare phenomenon is caused by the presence of two galaxies in the foreground that act as a lens.

These galaxies were imaged in spectacular detail by Hubble’s Wide Field Camera 3 (WFC3), which was installed on Hubble in 2009 during Hubble Servicing Mission 4, Hubble’s final servicing mission. The WFC3 was intended to operate until 2014, but 12 years after it was installed it continues to provide both top-quality data and fantastic images, such as this one.

The central pair of galaxies in this image are genuinely two separate galaxies. The four bright points circling them, and the fainter one in the very center, are actually five separate images of a single quasar (known as 2M1310-1714), an extremely luminous but distant object. The reason behind this “seeing quintuple” effect is a phenomenon known as gravitational lensing. Gravitational lensing occurs when a celestial object with an enormous amount of mass — such as a pair of galaxies — causes the fabric of space to warp such that the light travelling through that space from a distant object is bent and magnified sufficiently that humans here on Earth can observe multiple magnified images of the far-away source. The quasar in this image actually lies further away from Earth than the pair of galaxies. The light from the quasar has been bent around the galaxy pair because of their enormous mass, giving the incredible appearance that the galaxy pair are surrounded by four quasars — whereas in reality, a single quasar lies far beyond them!

Credits: ESA/Hubble & NASA, T. Treu; CC BY 4.0

Acknowledgment: J. Schmidt

This image shows an area close to the landing ellipse for NASA’s Mars 2020 Perseverance rover, which is expected to land within Jezero crater on 18 February 2021. Jezero crater was once the site of a lake, and the landing site is centred on an ancient river delta near the rim of the crater. Although the actual landing ellipse is just outside of this image, it was taken as part of an imaging campaign to study the rover's future neighbourhood, in preparation for its arrival.

The image was taken by the CaSSIS camera on the ESA-Roscosmos Exomars Trace Gas Orbiter on 23 April 2020. For scale, the prominent crater left of centre is about 2 km across.

Credits: ESA/Roscosmos/CaSSIS, CC BY-SA 3.0 IGO

The Copernicus Sentinel-2 mission takes us over Malé – the capital and most populous city in the Republic of Maldives.

The Republic of Maldives consist of a chain of around 1200 small coral islands that are grouped into clusters of atolls – scattered across 90 000 sq km of ocean. A number of these little islands can be seen in the image, with the turquoise colours depicting clear, shallow waters dotted by coral reefs which contrasts with the dark colours of the Indian Ocean.

Malé, located at the southern edge of the North Malé Atoll, can be easily spotted in the right of the image. The island is small enough to walk around in approximately one hour, with most sights concentrated on its northern shore. Malé is both a trade and tourist centre, connected with Sri Lanka and India by steamship lines, with several vessels visible in the image.

With a population of more than 200 000 and an area of around eight sq km, Malé is one of the most densely populated cities in the world with the city covering almost the entire island.

With more than 80% of the Maldives’ land standing less than one metre above average sea level, the Maldives has the lowest terrain of any country in the world. This makes the archipelago particularly vulnerable to sea-level rise.

In response to this rising threat, the Maldives is working on enhancing the resilience of the country’s islands, which includes constructing the artificial island of Hulhumale – visible northeast of the airport island of Hulhulé.

The island has been constructed by pumping sand from the seafloor onto a submerged coral platform, that rises around 2 m above sea level. The reclaimed land provides some much-needed space, and will also help meet the industrial and commercial development of the Malé region.

Satellite data have shown that the global ocean has risen, on average, 3 mm a year over the last 25 years. Warming ocean waters, melting glaciers and diminishing ice sheets is making rising sea levels a real threat for low-lying islands such as the Maldives.

Following liftoff in November 2020, the Copernicus Sentinel-6 Michael Freilich satellite, the most advanced mission dedicated to measuring sea-level rise, is now fully operational – meaning that its data are available to climate researchers, ocean-weather forecasts and other data users. Learn more about the Sentinel-6 mission here.

This image, also featured on the Earth from Space video programme, was captured by the Copernicus Sentinel-2 mission – a two-satellite mission to supply the coverage and data delivery needed for Europe’s Copernicus programme.

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

At first glance, this image may resemble red ink filtering through water or a crackling stream of electricity, but it is actually a unique view of our cosmic home. It reveals the central plane of the Milky Way as seen by ESA’s Planck satellite and the Atacama Pathfinder Experiment (APEX), which is located at an altitude of around 5100m in the Chilean Andes and operated by the European Southern Observatory.

This image was released in 2016 as the final product of an APEX survey mapping the galactic plane visible from the southern hemisphere at submillimetre wavelengths (between infrared and radio on the electromagnetic spectrum). It complements previous data from ESA’s Planck and Herschel space observatories.

Planck and APEX are an ideal pairing. APEX is best at viewing small patches of sky in great detail while Planck data is ideal for studying areas of sky at the largest scales. It covers the entire sky – no mean feat. The two work together well, and offer a unique perspective on the sky.

This image reveals numerous objects within our galaxy. The bright pockets scattered along the Milky Way’s plane in this view are compact sources of submillimetre radiation: very cold, clumpy, dusty regions that may shed light on myriad topics all the way from how individual stars form to how the entire Universe is structured.

From right to left, notable sources include NGC 6334 (the rightmost bright patch), NGC 6357 (just to the left of NGC 6334), the galactic core itself (the central, most extended, and brightest patch in this image), M8 (the bright lane branching from the plane to the bottom left), and M20 (visible to the upper left of M8). A labelled view can be seen here.

Planck was launched on 14 May 2009 and concluded its mission in October 2013. The telescope returned a wealth of information about the cosmos; its main aim was to study the Cosmic Microwave Background (CMB), the relic radiation from the Big Bang. Among other milestones, Planck produced an all-sky map of the CMB at incredible sensitivity and precision, and took the ‘magnetic fingerprint’ of the Milky Way by exploring the behaviour of certain light emitted by dust within our galaxy.

Its observations are helping scientists to explore and understand how the Universe formed, its composition and contents, and how it has evolved from its birth to present day.

APEX is a collaboration between the Max Planck Institute for Radio Astronomy, the Onsala Space Observatory, and the European Southern Observatory, ESO. The telescope is operated by ESO.

Credits: ESO/ATLASGAL consortium; ESA/Planck

On 12 October 2019, the NASA/ESA Hubble Space Telescope provided astronomers with their best look yet at an interstellar visitor — Comet 2I/Borisov — which is believed to have arrived here from another planetary system elsewhere in our galaxy.

This observation is the sharpest view ever of the interstellar comet. Hubble reveals a central concentration of dust around the solid icy nucleus.

Comet 2I/Borisov is only the second such interstellar object known to have passed through our Solar System. In 2017, the first identified interstellar visitor, an object dubbed ‘Oumuamua, swung within 38 million kilometres of the Sun before racing out of the Solar System.

Learn more.

Credits: NASA, ESA, D. Jewitt (UCLA); CC BY 4.0

This image, captured on 25 March 2020, shows the bottom of the 400 km in diameter Antoniadi impact crater, which is located in the northern hemisphere of Mars in the Syrtis Major Planum region. The blue colour of the image, centred at 21.0°N, 61.2°E, does not represent the real colour of the crater floor but highlights the diversity of the rock composition inside the impact crater.

In the centre of the image are dendritic structures which look like the veins on oak leaves. These structures, evidence of ancient river networks in this region, protrude from the surface, unlike channels, which are usually sunken in the surface. This is because the channels were filled with harder material – possibly lava – and over time the softer rocks surrounding these branching channels have been eroded, leaving an inverted imprint of this ancient river system.

Credits: ESA/ExoMars/CaSSIS

A 1:18 scale model of Juice, ESA’s spacecraft to explore the Jupiter system, is being employed to test its radar antenna.

The working version of the RIME instrument (Radar for Icy Moons Exploration), incorporating a 16-m long version of the straight ‘dipole’ boom seen here under the model spacecraft, will probe up to 9 km deep under the surfaces of the gas giant’s main ‘Galilean’ moons.

The testing took place in ESA’s Hertz (Hybrid European RF and Antenna Test Zone) chamber based at ESA’s ESTEC technical heart in the Netherlands.

Metal walls screen outside radio signals, while spiky foam interior cladding absorbs radio signals internally to create conditions simulating the infinite void of space.

This chamber’s hybrid nature makes it unique: Hertz can assess radio signals from antennas either on a local ‘near-field’ basis or as if the signal has crossed thousands of kilometres of space, allowing it to serve all kinds of satellites and antenna systems.

Watch a video on the testing here.

Credits: ESA-P. de Maagt

Asteroid Ryugu, an ancient space rock roughly 300 million km from Earth, is now home to three Earth-born inhabitants bouncing across its bouldery surface. In the early morning of 3 October 2018, the Mobile Asteroid Surface Scout (MASCOT) gently fell to the asteroid’s surface, joining its Japanese siblings, the MINERVA-II rovers 1-A and 1-B.

This remarkable image was taken during MASCOT’s descent, 3.5 minutes after separation from its parentship and 20 metres from its final resting place. At the top right, MASCOT’s fuzzy shadow can be seen, standing out next to the sharp detail of Ryugu’s puckered surface.

Developed by the German Aerospace Center (DLR) in cooperation with the French space agency CNES, MASCOT was originally thought to have enough power to explore the mile-long rock for just 12 hours. However, the adventurous box delighted its team when it inspected Ryugu’s surface for more than 17 hours, making an extra bounce and sending all the data collected back to the mothership, Hayabusa2.

The Hayabusa2 spacecraft left Earth in December 2014, carrying four small rovers designed to investigate Ryugu’s surface. Each fell freely to the surface under the asteroid’s weak gravity, bouncing on arrival and immediately collecting data on their strange new world.

The spacecraft is expected to return 3 samples to Earth in December 2020 from varying parts of the ancient asteroid. With these specimens, scientists on Earth hope to learn about the composition of carbonaceous asteroids like Ryugu — a type of space rock expected to preserve some of the most pristine materials in the Solar System.

This class of asteroid also has members who at times come too close to Earth for comfort, near-Earth objects (NEOs). It is hoped that Hayabusa’s incredible mission will shed light on these marauding masses which could come in handy if we one day need to defend ourselves from them.

Undoubtedly, Hayabusa’s insights into this giant pile of space rubble will prove useful to the teams involved in ESA’s ambitious proposed mission to test asteroid deflection, Hera— in particular, understanding the low gravity environment of these unique solar system bodies.

Credits: DLR

This image from ESA’s Mars Express shows Nectaris Fossae and Protva Valles, complex geological features found on Mars. Round impact craters are scattered across the frame, and a band of fractured grooves, resembling scratches and scars carved into the rock, stretches from the top left to bottom right.

This image comprises data gathered by Mars Express’ High Resolution Stereo Camera (HRSC) on 23 May 2022. It was created using data from the nadir channel, the field of view aligned perpendicular to the surface of Mars, and the colour channels of the HRSC. It is a ‘true colour’ image, reflecting what would be seen by the human eye if looking at this region of Mars.

North is to the right. The ground resolution is approximately 23 m/pixel and the image is centred at about 27°S/301°E.

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

This gigantic image of the Triangulum Galaxy — also known as Messier 33 — is a composite of about 54 different pointings with Hubble’s Advanced Camera for Surveys. With a staggering size of 34 372 times 19 345 pixels, it is the second-largest image ever released by Hubble. It is only dwarfed by the image of the Andromeda Galaxy, released in 2015

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The mosaic of the Triangulum Galaxy showcases the central region of the galaxy and its inner spiral arms. Millions of stars, hundreds of star clusters and bright nebulae are visible. This image is too large to be easily displayed at full resolution and is best appreciated using the zoom tool

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More info: Hubble takes gigantic image of the Triangulum Galaxy

Credits: NASA, ESA, and M. Durbin, J. Dalcanton, and B. F. Williams (University of Washington); CC BY 4.0

Space Science image of the week:

A young massive star that began life around 25 times more massive than our own Sun is shedding shells of material and fast winds to create this dynamic scene captured by ESA’s XMM-Newton.

The image shows the detailed structure of the Crescent Nebula that shed a shell of material as it expanded into a red giant some 200 000 years ago. Fast winds emitted more recently have now collided with that material, causing the gasses in the bubble to heat up and emit X-rays, seen as blue in the image.

Other features can also be seen, such as the green hue, generated by oxygen atoms, where the star’s wind is interacting with the surrounding interstellar medium.

Density differences in the surrounding material may give rise to the different structures, such as the extended bubble segment to the top right.

The star will likely end its life in a violent supernova explosion.

The Crescent Nebula sits in the constellation of Cygnus about 5000 light-years away, exactly at a location in the sky that has not been accessible to XMM-Newton until recently. Although it has been well studied by other X-ray telescopes, astronomers working on XMM-Newton, which was launched on 10 December 1999, had to wait patiently until the orbit of the satellite was such that this patch of sky moved into its field of view in April 2014.

More information about XMM-Newton’s observation is available in “X-ray emission from the Wolf-Rayet bubble NGC 688. II. XMM-Newton EPIC observations", by J. Toalá et al. (2015).

Credit: ESA/XMM-Newton, J. Toalá & D. Goldman

This image highlights the location of the galaxy JADES-GS-z6 in a portion of an area of the sky known as GOODS-South, which was observed as part of the JWST Advanced Deep Extragalactic Survey, or JADES.

This galaxy, along with others in this region, were part of a Webb study by an international team of astronomers, who observed the chemical signature of carbon-rich dust grains at redshift ~7. This is roughly equivalent to one billion years after the birth of the Universe. Similar observational signatures have been observed in the much more recent Universe, attributed to complex, carbon-based molecules known as polycyclic aromatic hydrocarbons (PAHs). It is not thought likely, however, that PAHs would have developed within the first billion years of cosmic time. Therefore, this observation suggests the exciting possibility that Webb may have observed a different species of carbon-based molecule: possibly minuscule graphite- or diamond-like grains produced by the earliest stars or supernovae. This observation suggests exciting avenues of investigation into both the production of cosmic dust and the earliest stellar populations in our Universe, and was made possible by Webb’s unprecedented sensitivity.

The team’s research indicates that this particular galaxy showed significant dust obscuration and has undergone substantial metal enrichment relative to galaxies with similar mass at the same redshift. The team also believes the galaxy's visible colour gradient may indicate a peculiar geometrical alignment of stars and dust.

In this image, blue, green, and red were assigned to Webb’s NIRCam (Near-Infrared Camera) data at 0.9, 1.15, and 1.5 microns; 2.0, 2.77, and 3.55 microns; and 3.56, 4.1, and 4.44 microns (F090W, F115W, and F150W; F200W, F277W, and F335M; and F356W, F410M, and F444W), respectively.

The galaxy is shown zoomed in on a region measuring roughly 1x1 arcseconds, which is a measure of angular distance on the sky. One arcsecond is equal to 1/3600 of one degree of arc (the full Moon has an angular diameter of about 0.5 degrees). The actual size of an object that covers one arcsecond on the sky depends on its distance from the telescope.

[Image description: The image shows a deep galaxy field, featuring thousands of galaxies of various shapes and sizes. A cutout indicates a particular galaxy, known as JADES-GS-z6, which was a research target for this result. It appears as a blurry smudge of blue, red and green.]

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Credits: ESA/Webb, NASA, ESA, CSA, B. Robertson (UC Santa Cruz), B. Johnson (Center for Astrophysics, Harvard & Smithsonian), S. Tacchella (University of Cambridge, M. Rieke (Univ. of Arizona), D. Eisenstein (Center for Astrophysics, Harvard & Smithsonian), A. Pagan (STScI)

This is a Hubble view of Uranus taken in 2014, seven years after the northern spring equinox when the Sun was shining directly over the planet’s equator, and shows one of the first images from the OPAL programme. Multiple storms with methane ice-crystal clouds appear at mid-northern latitudes above the planet’s cyan-tinted lower atmosphere. Hubble photographed the ring system edge-on in 2007, but the rings are seen starting to open up seven years later in this view. At this time, the planet had multiple small storms and even some faint cloud bands.

[Image description: Uranus is mainly coloured cyan. The planet looks like a flat circle outlined with a pinkish gray limb. Faint, pinkish gray bands and streaks run nearly vertically across Uranus, while splotches of white clouds dot the right half of the planet’s face. The right third of the planet appears mostly white and pinkish gray, as though that part of the atmosphere were thick with clouds.]

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Credits: NASA, ESA, STScI, A. Simon (NASA-GSFC), M. H. Wong (UC Berkeley), J. DePasquale (STScI); CC BY 4.0

This new image from ESA’s Mars Express shows the distinctive and fascinating Mawrth Vallis, one of the most promising locations on Mars in our search for signs of life.

The region is thickly coated in light-toned clays containing silicate minerals; these deposits – some 200 m deep in places – are the most widespread found on Mars, and are obviously visible in these new images. The light clays are overlaid by darker ‘caps’, which can also be clearly seen and are thought to be of volcanic origin. The silicates within these clays are evidence that the surface has been altered by water, hinting at a habitable environment in the past.

The clays are annotated here for clarity, alongside many other fascinating features: craters, highlands, dark volcanic rock units, crater walls and ejecta, lowlands, knobs and mesas.

This image was created from data collected by the Mars Express High Resolution Stereo Camera (HRSC) on 18 February 2023 during orbit 24164. North is to the right, the ground resolution is approximately 18 m/pixel, and the image is centred at about 25°N/339°E.

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

After abundant snowfall on 8 December 2021, here's a rare cloud-free Copernicus Sentinel-2 mission mosaic image of Liguria, Valle D'Aosta, Piedmont, Lombardy and a little portion of Tuscany in Italy.

Monte Rosa can be seen at the top left corner of the image.

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

This Picture of the Week shows a dwarf galaxy named UGC 685. Such galaxies are small and contain just a tiny fraction of the number of stars in a galaxy like the Milky Way. Dwarf galaxies often show a hazy structure, an ill-defined shape, and an appearance somewhat akin to a swarm or cloud of stars — and UGC 685 is no exception to this. Classified as an SAm galaxy — a type of unbarred spiral galaxy — it is located about 15 million light-years from Earth.

These data were gathered under the NASA/ESA Hubble Space Telescope’s LEGUS (Legacy ExtraGalactic UV Survey) Program, the sharpest and most comprehensive ultraviolet survey of star-forming galaxies in the nearby Universe.

LEGUS is imaging 50 spiral and dwarf galaxies in our cosmic neighbourhood in multiple colours using Hubble’s Wide Field Camera 3. The survey is picking apart the structures of these galaxies and resolving their constituent stars, clusters, groups, and other stellar associations. Star formation plays a huge role in shaping its host galaxy; by exploring these targets in detail via both new observations and archival Hubble data, LEGUS will shed light on how stars form and cluster together, how these clusters evolve, how a star’s formation affects its surroundings, and how stars explode at the end of their lives.

Credits: ESA/Hubble & NASA; the LEGUS team, B. Tully, D. Calzetti Acknowledgement(s): Judy Schmidt (Geckzilla); CC BY 4.0

Throughout human history, spectacular auroral eruptions have given rise to fearful beliefs of mythological creatures, have driven folklore and have influenced culture, religion and art.

Today, we know the aurora are the visible manifestations in our atmosphere of space weather, and occur when electrically charged particles from the Sun collide with Earth’s atmosphere. These particles are delivered by the ‘solar wind’ — a constant stream of electrons, protons and heavier ions — emitted by our Sun.

At the remote Concordia research station in Antarctica, a beautiful and harmless display of Aurora Australis or Southern Lights caught ESA-sponsored medical doctor Nadja Albertsen by surprise.

“I turn my gaze away from the horizon and dusk, there is a stripe in the sky that is not the Milky Way, at first just white and cloud-like, but there is no doubt – the green hues are visible and the curtain-like waves in the sky are unmistakable,” as she explains in her latest Concordia blog post.

Concordia is run by the French and Italian polar organisations to collect data for subjects as diverse as glaciology, astronomy and climate science.

For a whole year, Nadja facilitates a number of experiments on the effects of isolation, light deprivation, and extreme temperatures on the human body and mind.

“The aurora is an amazing experience and one that I don’t think anyone gets tired of – even if you live a lifetime with it as a frequent guest,” she adds.

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. Aurora remind us that we live with an active star that can do real damage to daily life.

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. Unpredictable and temperamental, our Sun blasts intense radiation and colossal amounts of energetic material in every direction, creating the ever-changing conditions in space known as ‘space weather’.

Aurora offer a visual means to study 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.

Follow Nadja’s adventures at Concordia on the blog.

Credits: ESA/IPEV/PNRA/ A. Mancini

Part of the Glacier Bay National Park and Preserve, which lies along the coast of southeast Alaska, is featured in this image captured by the Copernicus Sentinel-2 mission.

Covering over 13 000 sq km of rugged, snow-capped mountains, freshwater lakes, glaciers and deep fjords, Glacier Bay National Park and Preserve is one of the highlights of Alaska’s Inside Passage. As marine waters make up almost one-fifth of the park, Glacier Bay is rich with marine life, including humpback whales, orcas and sea otters. It’s also home to a large population of bears, moose, wolves and mountain goats.

The bay contains some of the world’s most impressive glaciers that descend from the ice-covered St. Elias Range in the east and the Fairweather Range in the west, with a few notable tidewater glaciers extending all the way to the sea.

John Hopkins Glacier, visible in the far left of the image, is the largest tidewater glacier in the region. Muir Glacier, formerly the most famous of the tidewater glaciers, once rose around 80 m above water and was nearly 3 km wide but has now shrunk and receded and no longer reaches the sea.

Glacier Bay is just one of the many areas suffering from the effects of global warming. The bay is expected to become warmer and drier over the next century, with widespread effects including the further shrinking glaciers, reduced sea ice and shoreline erosion.

Monitoring glaciers is often a challenge considering their sheer size, remoteness and rugged terrain they occupy. Satellites, including ESA’s CryoSat mission, with its elite spaceborne sensor – the radar altimeter – allows for the mapping of glaciers in fine detail. In a study published last year in the Cryosphere, scientists utilised data from the CryoSat mission to show how much ice had been lost from mountain glaciers in the Gulf of Alaska.

Today marks the opening of the ‘Earth’s Memory - glaciers witnesses to the climate crisis’ exhibition, that follows the scientific and photographic journey of glaciers around the world, premiering the results of the ‘On the trail of the glaciers’ project directed by Italian photographer Fabiano Ventura. The exhibition, which is being held in the Forte di Bard Museum, Aosta Valley, Italy, offers its visitors the opportunity to witness the effects of global warming through the power of both photography and ESA satellite imagery.

The exhibition focuses on the world’s largest mountain glaciers with 90 photographic comparisons displayed alongside scientific data collected during the team’s expedition to the world’s largest mountain glaciers. It runs until 18 November 2022 and includes images such as the one featured on this week’s Earth from Space programme. More information on the exhibition, which is part of a scientific collaboration between ESA and is sponsored by UNESCO, can be found here.

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

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

Euclid’s Near-Infrared Spectrometer and Photometer (NISP) instrument is dedicated to measuring the amount of light that galaxies emit at each wavelength. It will image the sky in infrared light (900–2000 nm) to measuring the brightness and intensity of light. This image was taken during commissioning of Euclid to check that the focused instrument worked as expected.

Before it reaches the detector, NISP sends incoming light through either a photometry filter or a spectrometry grism. In this image, the light from Euclid’s telescope has passed through the grism, which splits light from every star and galaxy by wavelength. This information can be pulled out and analysed to determine the type of galaxy and what its distance is.

Euclid’s telescope collected light for 100 seconds to enable NISP to create this image. During nominal operation, it is expected to collect light for roughly five times longer, unveiling many more distant galaxies.

Find out more

Credits: ESA/Euclid/Euclid Consortium/NASA, CC BY-SA 3.0 IGO

The NASA/ESA Hubble Space Telescope has established an extraordinary new benchmark: detecting the light of a star that existed within the first billion years after the Universe’s birth in the Big Bang (at a redshift of 6.2) — the most distant individual star ever seen. This sets up a major target for the NASA/ESA/CSA James Webb Space Telescope in its first year

This find is a huge leap back in time compared to the previous single-star record holder; detected by Hubble in 2018. That star existed when the universe was about 4 billion years old, or 30 percent of its current age, at a time that astronomers refer to as “redshift 1.5.” Scientists use the word “redshift” because as the Universe expands, light from distant objects is stretched or “shifted” to longer, redder wavelengths as it travels toward us.

But the newly detected star is so far away that its light has taken 12.9 billion years to reach Earth, appearing to us as it did when the universe was only 7 percent of its current age, at redshift 6.2. The smallest objects previously seen at such a great distance are clusters of stars, embedded inside early galaxies.

Thanks to the rare alignment with the magnifying galaxy cluster, the star Earendel appears directly on, or extremely close to, a ripple in the fabric of space. This ripple, which is known in optics as a “caustic,” provides maximum magnification and brightening. The effect is analogous to the rippled surface of a swimming pool creating patterns of bright light on the bottom of the pool on a sunny day. The ripples on the surface act as lenses and focus sunlight to maximum brightness on the pool floor.

This caustic causes the star Earendel to pop out from the general glow of its home galaxy. Its brightness is magnified a thousandfold or more. At this point astronomers are not able to determine whether Earendel is a binary star, but most massive stars do have at least one smaller companion star.

Astronomers expect that Earendel will remain highly magnified for years to come. It will be observed by the NASA/ESA/CSA James Webb Space Telescope later in 2022. Webb’s high sensitivity to infrared light is needed to learn more about Earendel, because its light is stretched (redshifted) to longer infrared wavelengths by the expansion of the Universe.

Check the annotated version of this image here.

Credits: NASA, ESA, B. Welch (JHU), D. Coe (STScI), A. Pagan (STScI); CC BY 4.0

This large expanse of space captured with the Hubble Space Telescope features the galaxy SDSSJ225506.80+005839.9. Unlike many other extravagant galaxies and stunning nebulae imaged by Hubble, this galaxy does not have a short popular name, and is only known by its long SDSS name, which refers to its coordinates in the sky. This galaxy - visible in the center right portion of the image - and its many wondrous neighbouring galaxies lie in the constellation of Pisces (The Fish). This is a post-starburst galaxy, which is a product of galaxies that have merged within the past billion years. This merger event drove gas to the galaxy's center and created an abundance of new stars, of which the brightest are visible in the remnant galaxy's core. The visible shells and tails surrounding the galaxies are also a result of this merger event. Residing far beyond our own Milky Way, it is almost impossible to glimpse this galaxy without the assistance of Hubble, and, like thousands of similar faint and very distant galaxies, it was only discovered and catalogued in recent years. Many millions of galaxies still await our discovery as we build a wondrous picture of our night sky.

This large expanse of space captured with the Hubble Space Telescope features the galaxy SDSSJ225506.80+005839.9. Unlike many other extravagant galaxies and stunning nebulae imaged by Hubble, this galaxy does not have a short popular name, and is only known by its long SDSS name, which refers to its coordinates in the sky. This galaxy - visible in the center right portion of the image - and its many wondrous neighbouring galaxies lie in the constellation of Pisces (The Fish).

This is a post-starburst galaxy, which is a product of galaxies that have merged within the past billion years. This merger event drove gas to the galaxy's center and created an abundance of new stars, of which the brightest are visible in the remnant galaxy's core. The visible shells and tails surrounding the galaxies are also a result of this merger event.

Residing far beyond our own Milky Way, it is almost impossible to glimpse this galaxy without the assistance of Hubble, and, like thousands of similar faint and very distant galaxies, it was only discovered and catalogued in recent years. Many millions of galaxies still await our discovery as we build a wondrous picture of our night sky.

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

The Shetland Islands, an archipelago in the Northern Isles of Scotland, are featured in this Copernicus Sentinel-2 image.

Lying roughly 100 km north of the Scottish mainland, the Shetland Islands separate the Atlantic Ocean on the west from the North Sea to the east. The archipelago comprises around 100 islands and islets, with fewer than 20 of them inhabited. The islands cover an area of around 1468 sq km and have a rugged coastline approximately 2700 sq km long.

The largest island, known as the Mainland, has an area of around 900 sq km, making it the third-largest Scottish island. The next largest are Yell, Unst and Fetlar, which lie in the north, as well as Bressay and Whalsay, which lie to the east. Lerwick, located on Mainland, is the capital and largest settlement of the archipelago.

The most striking feature in this week’s image, captured on 1 July 2021, is the vivid, turquoise-coloured bloom visible to the east of the islands. This type of bloom is slightly different to the harmful cyanobacteria often visible around the Baltic Sea. In the absence of any known samples being analysed, it is assumed that it is a coccolithophore bloom – a type of microscopic marine algae living in the upper layer of the sea. Like all phytoplankton, coccolithophores contain chlorophyll and have the tendency to multiply rapidly near the surface.

In large numbers, coccolithophores periodically shed their tiny scales called ‘coccoliths’ into the surrounding waters. These calcium-rich coccoliths turn the normally dark water a bright, milky-turquoise colour. Although invisible to the eye, in large quantities, they are easy to spot in satellite imagery. These types of algae play a huge role in the ocean uptake of atmospheric carbon dioxide, as their shells sink to deeper ocean depths after they die, storing carbon in the process.

This year’s edition of the United Nations climate change conference – COP26 – is taking place in Scotland from 31 October to 12 November. The summit aims to inspire faster and more ambitious action from the international community to achieve the goal of limiting global temperature rise to 1.5°C. As in previous years, ESA has a strong presence at COP26, showcasing how satellite data strengthens our understanding of climate from space. Read more about ESA’s role at COP.

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

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

The James Webb Space Telescope lifted off on an Ariane 5 rocket from Europe’s Spaceport in French Guiana, at 13:20 CET on 25 December on its exciting mission to unlock the secrets of the Universe.

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Credits: ESA/CNES/Arianespace

ESA astronaut Luca Parmitano captured this image of the island of Sicily and shared it on his social media channels saying: "Like a dusting of powdered sugar, fair weather clouds whiten the lands of my youth."

Follow Luca and his Beyond mission on social media on his website and on his blog.

Credits: ESA/NASA - L.Parmitano

This zoomed-in image of Uranus, captured by Webb’s Near-Infrared Camera (NIRCam) on 6 February 2023, reveals stunning views of the planet’s rings. The planet displays a blue hue in this representative-colour image, made by combining data from two filters (F140M, F300M) at 1.4 and 3.0 microns, shown here as blue and orange, respectively.

On the right side of the planet is an area of brightening at the pole facing the Sun, known as a polar cap. This polar cap is unique to Uranus because it is the only planet in the Solar System that is tilted on its side, which causes its extreme seasons. A new aspect of the polar cap revealed by Webb is a subtle brightening near the Uranian north pole.

At the edge of the polar cap lies a bright cloud and a few fainter extended features can be seen just beyond the cap’s edge; a second very bright cloud is seen at the planet’s left limb. Such clouds are typical for Uranus at infrared wavelengths, and are likely connected to storm activity.

Learn more here

[Image description: The planet Uranus on a black background. The planet appears light blue with a large, white patch on the right side. On the edge of that patch at the upper left is a bright white spot. Another white spot is located on the left side of the planet at the 9 o’clock position. Around the planet is a system of nested rings. The rings of Uranus are vertical.]

Credits: NASA, ESA, CSA, STScI, J. DePasquale (STScI)

Hubble’s measurements of today’s expansion rate do not match the rate that was expected based on how the Universe appeared shortly after the Big Bang over 13 billion years ago. Using new data from the NASA/ESA Hubble Space Telescope, astronomers have significantly lowered the possibility that this discrepancy is a fluke.

Learn more about this discovery here

Credits: NASA, ESA. Acknowledgement: Josh Lake; CC BY 4.0

The Copernicus Sentinel-2 mission takes us over El Oued, in northeast Algeria, about 80 km west of the border with Tunisia.

Shown as a dark elongated area in the centre of the image, the town of El Oued lies around an oasis in the northern Sahara, in a region that is otherwise an endless sea of sand.

This false-colour image has been processed using the mission’s near-infrared channel to display vegetation in red, with irrigated vegetation shown in bright red and non-irrigated areas appearing in darker red tones. These vegetated areas stand out clearly in the surrounding gold sand dunes shaped by the wind.

Most of the agricultural fields in the image are circular, indicating that central-pivot irrigation systems are being used. A well, drilled in the centre of each circle, supplies water to rotating sprinklers that spray water in a circular pattern. Each of the circles is around 100 m in diameter. The main crops here include potatoes, onions and tomatoes.

Date palms are also very important for the local economy. They are typically grown using traditional methods inside irregular funnel-shaped fields in the sand. They do not need to be irrigated frequently and can be spotted in dark colours throughout the image, such as around El Oued and to the south of the town of Hassani Abdelkrim, northeast of El Oued.

While providing detailed information about Earth’s vegetation, Copernicus Sentinel-2 plays a key role in mapping differences in land cover to understand how it is used and to track changes over time, so useful for monitoring desertification. The mission also provides measurements of water quality and detects changes in water bodies, supporting sustainable water management – a valuable tool for arid areas where water is scarce.

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

Say cheese.

Amateur astrophotographer Javier Manteca captured the International Space Station as flew in front of the Moon on 5 February.

While most eyes were on the change of command ceremony taking place inside the Space Station ahead of ESA astronaut Luca Parmitano’s return to Earth, Javier set up his gear to track the Station from the small town of Campo Real in Madrid, Spain.

Using a camera attached to a 150/750 telescope recording at 25 frames per second, Javier captured the 690 millisecond transit on video and composed this image made from 17 stacked frames.

For Javier, this was a moment two years in the making. He posted the image to his Twitter and Instagram, where you can find more of his work.

Luca returned to Earth the day after this photo, on 6 February, ending a record-breaking 201 days in space for his Beyond mission.

Highlights of his mission include four complex sorties that earned him the European record for most cumulative hours spent on spacewalks, remotely operating a rover in the Netherlands from space, and being the first Italian European commander of the Station.

Another European milestone was met this week. The Orion spacecraft that will fly around the Moon on the Artemis-1 mission completed thermal-vacuum testing in the world’s largest vacuum chamber at NASA’s Plum Brook Station in Ohio, USA.

ESA’s contribution to the mission is the European Service Module that will power the vehicle as well as provide electricity, water, oxygen and nitrogen and keep the spacecraft at the right temperature and on course.

From 26 December until 9 February, the spacecraft was subjected to environmental temperatures varying from –175°C to 75°C to give it its first taste of space. Read more about it on the ESA Orion blog. The spacecraft will be reconfigured for electromagnetic testing, to begin at the end of the month.

Credits: Javier Manteca

Ferocious bushfires have been sweeping across Australia since September, fuelled by record-breaking temperatures, drought and wind. The country has always experienced fires, but this season has been horrific. A staggering 10 million hectares of land have been burned, at least 24 people have been killed and it has been reported that almost half a billion animals have perished.

The Copernicus Sentinel-2 mission has been used to image the fires. The Sentinel-2 satellites each carry just one instrument – a high-resolution multispectral imager with 13 spectral bands. The smoke, flames and burn scars can be seen clearly in the image shown here, which was captured on 31 December 2019. The large brownish areas depict burned vegetation and provide an idea of the size of the area affected by the fires here – the brown ‘strip’ running through the image has a width of approximately 50 km and stretches for at least 100 km along the Australian east coast.

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

Astronomers using the NASA/ESA Hubble Space Telescope watched a mysterious dark vortex on Neptune abruptly steer away from a likely death on the giant blue planet.

The storm, which is wider than the Atlantic Ocean, was born in the planet's northern hemisphere and discovered by Hubble in 2018. Observations a year later showed that it began drifting southward toward the equator, where such storms are expected to vanish from sight. To the surprise of observers, Hubble spotted the vortex change direction by August 2020, doubling back to the north. Though Hubble has tracked similar dark spots over the past 30 years, this unpredictable atmospheric behaviour is something new to see.

Equally as puzzling, the storm was not alone. Hubble spotted another smaller dark spot in January this year that temporarily appeared near its larger cousin. It might possibly have been a piece of the giant vortex that broke off, drifted away, and then disappeared in subsequent observations.

Credits: NASA, ESA, STScI, M.H. Wong (University of California, Berkeley) and L.A. Sromovsky and P.M. Fry (University of Wisconsin-Madison); CC BY 4.0

By studying the rocks inside impact craters like this one, ESA research fellow Joana S. Oliveira has found that the location of Mercury’s magnetic field has changed over time in surprising ways.

Just like Earth, Mercury has a liquid metallic core, the motions within generating the magnetic field. On Earth, our magnetic north and south poles drift between about 10 and 60 km per year, with our planet’s magnetic field orientation flipping more than 100 times in the course of its 4.5 billion years.

Joana used data from NASA’s MESSENGER mission, which orbited Mercury from 2011-2015, to try to better understand the magnetic history of the innermost planet. The results of the study will help inform investigations to be conducted by the joint ESA/JAXA BepiColombo mission that is on route to the planet, arriving in 2025.

Scientists use rocks to study how planets’ magnetic fields evolve. Volcanic rocks created from cooling lava, or rocks that have become molten in large impact events are particularly useful tools. As the rocks cool, any magnetic materials contained with them aligns with the current field, preserving the direction and position of the planet’s magnetic field like a snapshot in time.

Joana and her colleagues used spacecraft observations from five craters with magnetic irregularities. One of the craters, named Rustaveli and found in the northern hemisphere, is pictured here. The craters were suspected to have formed during a time with a different core magnetic field orientation than that of today. The researchers modeled Mercury’s ancient magnetic field based on the crater data to estimate the potential locations for the poles in the past.

They found them to be far from the current position, and could have changed throughout time. They expected the poles to be clustering at two points closer to Mercury’s rotational axis at the geographic north and south of the planet. However, the poles were randomly distributed and were all found in the southern hemisphere. The ancient poles do not align with Mercury’s current magnetic north pole or geographic south, indicating the planet’s dipolar magnetic field has moved. The results also suggest the planet may have shifted along its axis, in an event called a true polar wander, where the geographic locations of the north and south poles change.

While it is not unusual for a planet’s field to change, the new results reinforce the idea that Mercury’s magnetic evolution was very unlike Earth’s. The dual scientific orbiters of the BepiColombo mission will gather unique magnetic field data and potentially narrow the study’s conclusions, while also helping us to place our own planet’s magnetic evolution in context.

The new research is published in the AGU Journal of Geophysical Research.

Read a review of the article on the AGU blog.

Find out more about ESA’s research fellowships (the next application deadline is 1 October).

Credits: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

It might be considered cheating, as this picture was taken over two Moons ago, but this Moonrise seen from the International Space Station deserves extra attention - and so, we are submitting this image for NASA’s Moon Snap.

Taken by ESA astronaut Samantha Cristoforetti from orbit during her Minerva mission, it is a sight rarely seen: Earth’s natural satellite appearing over the horizon above the always-distinctive Nile delta at night -- taken from 400 km above our planet. The brighter dot in the middle is the planet Venus.

The Moon is the only place that has been seen by every human being on our planet, but only around 600 astronauts have seen the Moon from Earth orbit. NASA’s Moon snap project is inviting people all over the world to share their Moon art to be featured during the launch coverage of the Artemis I mission, the first human-rated spacecraft to fly to the Moon in over fifty years.

This image does not need to be featured on the day of the Artemis launch; ESA’s European Service Module will be featured heavily already as the powerhouse that will drive the Orion spacecraft to the Moon and back. Samantha is circling our planet around 400 km above, but Orion will travel over 1250 times farther afield, more than half a million kilometres from its launchpad at NASA’s Kennedy Space Center in Florida, USA.

Join the celebrations as humankind explores farther and submit your art for NASA Moon snap, and watch the Artemis I launch, the first launch opportunity is on 29 August 2022. Follow Samantha and her Minerva mission for more amazing pictures from space.

Credits: ESA/NASA-S. Cristoforetti

The Copernicus Sentinel-3 mission captured this image of the Mediterranean hurricane, or ‘Medicane,’ crossing the Ionian Sea and approaching Greece yesterday 17 September at 10:48 CEST. Medicane Ianos, set to make landfall over Greece today, is expected to bring hurricane-force winds and heavy rain.

Medicanes are similar in form to hurricanes and typhoons, but can form over cooler waters. While hurricanes move east to west, medicanes move from west to east.

Sentinel-3 is a two-satellite mission to supply the coverage and data delivery needed for Europe’s Copernicus environmental monitoring programme. Each satellite’s instrument package includes an optical sensor to monitor changes in the colour of Earth’s surfaces.

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

ESA astronauts Alexander Gerst and Samantha Cristoforetti stand in a Norwegian fjord escorted by a waning crescent Moon. The pair is fully equipped for their first field expedition on lunar geology, as part of an intensive training week with ESA’s PANGAEA course.

Alexander and Samantha are wearing a digitally enhanced geology toolkit: a belt with a microscope, a spectrometer and a chest rig with a tablet to record their movements and document their findings. The astronauts also carry a rock hammer, a magnifying lens, sampling bags, a magnet and cue cards to help them identify rocks for science.

The duo was about to embark on a hunt to locate rare Earth rocks similar to those found in the heavily cratered highlands of the Moon – anorthosites. These rocks are billions of years old and originated from deep within the Earth. Anorthosites have been carved by Arctic glaciers in the mountains surrounding the small fishing village of Nusfjord.

Top European planetary scientists follow the astronauts closely to fill any knowledge gaps the might have about lunar science. The trainees have gained an extensive set of geological knowledge and skills, and are trained to work with scientists and explore autonomously as if they were exploring the surface of the Moon.

Alexander and Samantha are also supported by a series of tools and an app, a sort of ‘space tablet’ called the Electronic Field Book that helps them identify and record minerals and rocks, interact with a remote science team and collect the promising samples.

The digital tool is tested in each PANGAEA edition to support lunar exploration with future NASA Artemis missions in mind.

Follow their lunar steps on ESA’s PANGAEA blog, Twitter and Flickr.

Credits: ESA–V. Crobu

ESA astronaut Luca Parmitano captured this image of Greece from the International Space Station and shared it on his social media channels saying: "Crib of history and mother of culture, land of ancient heroes and explorers - a flight over Greece. We’re sending our greetings from the peak of science and technology."

Follow Luca and his Beyond mission on social media on his website and on his blog.

Credits: ESA/NASA-L.Parmitano

When astronomers use the NASA/ESA Hubble Space Telescope to study the deep sky, asteroids from our Solar System can leave their marks on the captured pictures of far-away galaxies or nebulae. But rather than be annoyed at the imprinted trails in Hubble images, astronomers realised they could use them to find out more about the asteroids themselves.

To do this, a team of ESA astronomers and software engineers started the Hubble Asteroid Hunter citizen science project in June, enlisting the public to help them find asteroids observed by chance in Hubble archival images. Through this project, over 1900 volunteers have identified more than 300 000 asteroid trails in nearly 11 000 images in only 1.5 months, completing the project with swiftness and enthusiasm that exceeded the team’s expectations.

Astronomy-enthusiast Melina Thévenot from Germany was one of the project’s keen volunteers. While analysing Hubble data, she found an asteroid trail on the foreground of a 2005 image of the Crab Nebula, one of the night sky's most famous objects.

Inspired by this impressive combination, Melina decided to process the original Hubble image combining views taken in blue, green and red filters, to create the stunning colour scene portrayed here. The faint trail of 2001 SE101, a main-belt asteroid discovered by the ground-based LINEAR survey in 2001, appears as a curved streak that crosses the image from bottom left to top right, near the nebula’s centre.

The Crab Nebula, also known as Messier 1 or M1, was the first object recorded by French astronomer Charles Messier in his famous catalogue of deep-sky objects. It is the expanding remnant of a bright supernova explosion observed by astronomers in 1054. Aside from the swirling cloud of gas and dust, the explosion left behind a rapidly rotating neutron star at the centre of the nebula, also visible in this image as the leftmost star in the bright pair at the centre of the picture.

While the chance alignment of a relatively nearby object – the asteroid – with the distant nebula is fascinating, it is not completely unexpected. In fact, the Crab Nebula, which has been observed by Hubble on nearly 300 occasions, fortuitously lies close to the ecliptic – the orbital plane where most asteroids reside in the Solar System – so it was only a matter of time before one of them ‘photobombed’ an observation of this iconic supernova remnant.

Now that volunteers have perused the platform to spot and mark asteroid trails, it is astronomers’ turn to get to work. Knowing the date and time when the Hubble images were taken, they can use the trails marked in the pictures to infer asteroids’ positions and velocities. This means they can determine the orbits and future trajectories of known and previously unknown asteroids with greater precision than before.

This knowledge is especially important for near-Earth objects: precisely determining the orbits of these asteroids can help protect our planet from possible impacts.

Meanwhile, the ESA team is planning to add new data to the Hubble Asteroid Hunter project soon, so users will have another chance to inspect Hubble images in search of passing asteroids. Stay tuned!

This stunning scene and the Hubble Asteroid Hunter project were made possible thanks to Zooniverse, the world’s largest citizen-science platform. The project was initiated by ESA research fellow Sandor Kruk, graduate student Max Mahlke, software engineers Elena Racero and Fabrizio Giordano from the ESAC Science Data Centre (ESDC) near Madrid, Spain, and Bruno Merín, head of the ESDC.

Credits: ESA/Hubble & NASA, M. Thévenot (@AstroMelina); CC BY 4.0