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This image from the NASA/ESA Hubble Space Telescope captures the sparkling globular cluster NGC 6569 in the constellation Sagittarius. Hubble explored the heart of this cluster with both its Wide Field Camera 3 and Advanced Camera for Surveys, revealing a glittering hoard of stars in this astronomical treasure trove.
Globular clusters are stable, tightly bound clusters containing tens of thousands to millions of stars, and are associated with all types of galaxies. The intense gravitational attraction of these closely packed clusters of stars means that globular clusters have a regular spherical shape with a densely populated centre — as can be seen in the heart of this star-studded image.
This observation comes from an investigation of globular clusters which lie close to the centre of the Milky Way. These objects have been avoided in previous surveys, as the dust spread throughout the centre of our galaxy blocks light from these globular clusters and alters the colours of the stars residing in them. The last factor is particularly important for astronomers studying stellar evolution, as the colours of stars can give astronomers insights into their ages, compositions, and temperatures.
The astronomers who proposed these observations combined data from Hubble with data from astronomical archives, allowing them to measure the ages of globular clusters including NGC 6569. Their research also provided insights into the structure and density of globular clusters towards the centre of the Milky Way.
Credits: ESA/Hubble & NASA, R. Cohen; CC BY 4.0
Space Science image of the week is this striking perspective view from ESA’s Mars Express. It shows an unnamed but eye-catching impact crater on Mars. This region sits south-west of a dark plain named Mare Serpentis (literally ‘the sea of serpents’), which in turn is located in Noachis Terra (literally ‘the land of Noah’).
Noachis Terra is one of the oldest known regions on the Red Planet, dating back at least 3.9 billion years— in fact, the earliest martian era, the Noachian epoch, is named after it. Noachis Terra is representative of ancient Mars’ surface, which is characteristically peppered with craters that have been preserved for billions of years, although many have degraded over time.
The crater visible on the top right of this image is around 4 km deep and 50 km in diameter. At its very centre is a small depression known as a central pit. These are common in craters on rocky worlds throughout the Solar System, especially on Mars, and are thought to form as icy material explosively vaporises and turns to gas in the heat of the initial crater-forming collision.
The outer walls around the crater are slightly raised above its surroundings. These stacked deposits may have formed during the impact that carved out the crater itself. As a rocky impactor slammed into the surface of Mars it likely compacted the loose and powdery material — small-grained dust and soil dubbed ‘regolith’ — to form a small plateau that has stood the test of time.
Just within the crater walls are channels and valleys threading and weaving down the inner slope — these are thought to have been carved and sculpted by running water. This water, locked up within the soil as groundwater and ice, would have melted as the Sun illuminated the crater walls, driving fluvial erosion processes and sketching thin lines down towards the centre of the crater.
This image was created using data from the Mars Express High Resolution Stereo Camera’s stereo channels (resulting in this oblique perspective) as well as its colour and nadir channels (creating the colour). The data were obtained on 29 July 2015 during orbit 14680. The resolution is approximately 14 m per pixel and the image is centred at 37° East and 35° South.
The image is a perspective view from a series that includes a colour nadir view, a colour-coded digital terrain model and a 3d anaglyph.
Credit:ESA/DLR/FU Berlin, CC BY-SA 3.0 IGO
The star nicknamed Earendel (indicated here with an arrow) is positioned along a ripple in spacetime that gives it extreme magnification, allowing it to emerge into view from its host galaxy, which appears as a red smear across the sky. The whole scene is viewed through the distorted lens created by a massive galaxy cluster in the intervening space, which allows the galaxy's features to be seen, but also warps their appearance—an effect astronomers call gravitational lensing. The red dots on either side of Earendel are one star cluster that is mirrored on either side of the ripple, a result of the gravitational lensing distortion. The entire galaxy, called the Sunrise Arc, appears three times, and knots along its length are more mirrored star clusters. Earendel's unique position right along the line of most extreme magnification allows it to be detected, even though it is not a cluster.
With this observation, 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.
Learn more here.
Credits: NASA, ESA, B. Welch (JHU), D. Coe (STScI), A. Pagan (STScI); CC BY 4.0
This Picture of the Week features two interacting galaxies that are so intertwined, they have a collective name — Arp 91. This delicate galactic dance is taking place over 100 million light-years from Earth, and was captured by the NASA/ESA Hubble Space Telescope. The two galaxies comprising Arp 91 do have their own names: the lower galaxy, which in this image looks like a bright spot, is known as NGC 5953; and the ovoid galaxy to the upper right is NGC 5954. In reality, both of these galaxies are spiral galaxies, but their shapes appear very different because they are orientated differently with respect to Earth.
Arp 91 provides a particularly vivid example of galactic interaction. NGC 5954 is clearly being tugged towards NGC 5953 — it looks like it is extending one spiral arm downwards. It is the immense gravitational attraction of the two galaxies that is causing them to interact. Such gravitational interactions between galaxies are common, and are an important part of galactic evolution. Most astronomers nowadays believe that collisions between spiral galaxies lead to the formation of another type of galaxy, known as elliptical galaxies. These immensely energetic and massive collisions, however, happen on timescales that dwarf a human lifetime — they take place over hundreds of millions of years. So we should not expect Arp 91 to look any different over the course of our lifetimes!
Credits: ESA/Hubble & NASA, J. Dalcanton; CC BY 4.0
Acknowledgement: J. Schmidt
This photograph, taken a short hike from the Geographic South Pole in Antarctica, shows some of the antennas comprising the Super Dual Auroral Radar Network (SuperDARN) array. They are visible here as the chain of antennas and wiring stretching away into the distance. The red lights along the horizon in the background are lights marking the entrances to the Amundsen-Scott research station, which lies a good kilometre distant.
SuperDARN is a network of radar antennas that monitors and explores the geomagnetic effects occurring in the Earth’s upper atmosphere. While some of these antennas are located at the South Pole, the network stretches worldwide and antennas are found in both the northern and southern hemispheres. One such geomagnetic effect is neatly captured here as wispy curtains and streaks of green filling the dark night sky above the antennas themselves: an aurora.
Auroras, informally known as polar lights, form as charged particles from the Sun flow into our region of space, hit the outer boundary of Earth’s magnetic field, and move further inwards to collide with the atoms and molecules in our planet’s atmosphere. The aurora seen here is known as aurora australis, or the southern lights.
Such phenomena form a key component of ‘space weather’, dynamic changes in the Earth’s cosmic environment that are driven by the activity of the Sun. As these can affect the function of both space-borne and ground-based systems and services, it’s crucial to monitor space weather in order to predict and mitigate its adverse effects. ESA does so via the Space Situational Awareness Space Weather Segment, and various science missions such as Cluster and Swarm, along with dedicated Sun-watching satellites to better understand our nearest star as a complete system.
This image was taken by ESA research fellow Daniel Michalik, who wintered at the Amundsen–Scott South Pole Station in Antarctica in 2017. It was taken as a single long exposure with minor contrast and exposure adjustments. At extremely cold temperatures of -60°C, Daniel was required to layer up, use a hot water bottle to keep the camera warm, and to pack his pockets with plentiful spare batteries. The photographer’s stoicism paid off, as the image was shortlisted as a finalist in the Royal Society photography competition in 2017. Another of Daniel’s images, published here, was the overall winner of the ‘Astronomy’ category.
Between 3 and 5 March ESA is highlighting the effects of space weather with the #AuroraHunters SocialSpace event at the other 'end' of the planet, in Tromsø, Norway. Follow the conversation on Twitter to see more great aurora images!
Credits: D. Michalik/NSF/SPT
An energetic outburst from an infant star streaks across this image from the NASA/ESA Hubble Space Telescope. This stellar tantrum — produced by an extremely young star in the earliest phase of formation — consists of an incandescent jet of gas travelling at supersonic speeds. As the jet collides with material surrounding the still-forming star, the shock heats this material and causes it to glow. The result is the colourfully wispy structures, which astronomers refer to as Herbig–Haro objects, billowing across the lower left of this image.
Herbig–Haro objects are seen to evolve and change significantly over just a few years. This particular object, called HH34, was previously captured by Hubble between 1994 and 2007, and again in glorious detail in 2015. HH34 resides approximately 1250 light-years from Earth in the Orion Nebula, a large region of star formation visible to the unaided eye. The Orion Nebula is one of the closest sites of widespread star formation to Earth, and as such has been pored over by astronomers in search of insights into how stars and planetary systems are born.
The data in this image are from a set of Hubble observations of four nearby bright jets with the Wide Field Camera 3 taken to help pave the way for future science with the NASA/ESA/CSA James Webb Space Telescope. Webb — which will observe at predominantly infrared wavelengths — will be able to peer into the dusty envelopes surrounding still-forming protostars, revolutionising the study of jets from these young stars. Hubble’s high-resolution images of HH34 and other jets will help astronomers interpret future observations with Webb.
Credits: ESA/Hubble & NASA, B. Nisini; CC BY 4.0
This image from ESA’s Mars Express shows a portion of the Uzboi-Ladon-Morava (ULM) outflow system, which may have once drained up to 9% of the martian surface.
This image comprises data gathered by Mars Express’ High Resolution Stereo Camera (HRSC) on 24 April 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.
The ground resolution is approximately 19 m/pixel and the image is centred at about 329°E/25°S. North is to the right.
Credits: ESA/DLR/FU Berlin, CC BY-SA 3.0 IGO
The Copernicus Sentinel-2 mission takes us over the Pyrenees Mountains in southwest Europe. The mountain range forms a natural border between France and Spain with the small, landlocked country of Andorra sandwiched in between.
Stretching from the shores of the Mediterranean Sea on the east to the Bay of Biscay (Atlantic Ocean) on the west, this international mountain range is 430 km long. The area pictured in this image, captured on 30 January 2022, spans around 120 km from the village of Escallare in the east to Panticosa to the west.
Located in the Spanish province of Huesca in the Posets-Maladeta Natural Park lies Pico de Aneto, the highest mountain peak in the Pyrenees. It rises to an elevation of 3404 m and is also the third-highest mountain in Spain. Click on the circle in the image to take a closer look at Pico de Aneto.
Geological studies have revealed that the Pyrenees Mountains have been around for longer than the Alps, with their sediments first deposited in coastal basins during the Paleozoic and Mesozoic eras. The entire mountain range formed due to the upwelling of large sedimentary rocks by the collision of the Iberian and the Eurasian plate around 100 to 150 million years ago, followed by intense erosion from ice and water.
Snow covers many of the peaks year-round, especially those in the centre-section of the chain. The western Pyrenees typically receive greater precipitation than the eastern Pyrenees owing to moisture blowing in from the Atlantic Ocean. The mountain range is also home to several small glaciers, as well as many mountain lakes and some of the highest waterfalls in Europe including Gavarnie Falls which, at 422 m, is France’s highest waterfall.
Few people live at the Pyrenees’ highest elevations; however, Andorra is nestled among peaks near the eastern end of the chain (not visible in the image). With an area of around 468 sq km, Andorra is the sixth smallest country in Europe.
The Copernicus Sentinel-2 mission is designed to play a key role in mapping differences in land cover to understand the landscape, map how it is used and monitor changes over time. As well as providing detailed information about Earth’s vegetation, it can also systematically map different classes of cover such as forest, grassland, water surfaces and artificial cover like roads and buildings.
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
Catastrophic flooding caused by several hours of heavy rainfall struck the Marche region in central Italy on 15 September 2022. These Copernicus Sentinel-3 image show the area after the torrential rains on 18 September after the event, sediment plumes are very evident all along the Adriatic coast.
Credits: contains modified Copernicus Sentinel data (2022), processed by ESA, CC BY-SA 3.0 IGO
This Copernicus Sentinel-2 image acquired on 11 July 2023 shows unusual emerald green waters in the Bay of Naples, Italy.
According to the Regional Environmental Protection Agency of Campania, where Naples is, this phenomenon has already happened in past summers.
A combination of high sea temperatures and a slower water exchange in the Bay led to a proliferation of phytoplankton. Recent tests on the waters reported a sea temperature of about 29 degrees, lower salinity than average but a higher-than-usual concentration of chlorophyll.
Credits: contains modified Copernicus Sentinel data (2023), processed by ESA, CC BY-SA 3.0 IGO
It is always reassuring to catch that first familiar glimpse of home after a great adventure, but for our space-faring satellites the return visit is brief and of a practical nature: to use the planet’s immense gravity to sling it onto a new trajectory.
These ‘gravity assists’ are fleeting encounters, but enough to change the spacecraft’s speed and direction such that it can eventually enter orbit around another world.
This delicate view of Earth was captured in 2007 on the second of three Earth flybys made by ESA’s comet-chasing Rosetta spacecraft on its ten year journey to Comet 67P/Churyumov-Gerasimenko. The spacecraft also got a boost from Mars to set it on course with its destination.
The first ever interplanetary gravity slingshot took place on 5 February 1974, when NASA’s Mariner 10 flew past Venus en route to flybys of Mercury. The ESA-JAXA BepiColombo mission – whose name is inherited from Giuseppe Colombo who originally proposed to NASA the interplanetary trajectories that would allow Mariner-10 multiple Mercury flybys by using gravity assists at Venus – will make nine flybys of Earth, Venus and Mercury to reach the innermost planet and eventually enter orbit about it.
Similarly, ESA’s upcoming Solar Orbiter mission will use Venus gravity assists to change its inclination to get a better look at the Sun’s poles. And ESA’s Jupiter Icy Moons Explorer will first dive into the inner Solar System to use Earth, Venus and Mars to set course for the gas giant Jupiter.
But Earth remains home to a fleet of satellites busy performing a number of different activities from orbit: while some are peering far away into the cosmos, our Earth Observation missions are watching diligently over our precious planet, taking its ‘pulse’ and helping us to better understand how to care for it. The Sun-illuminated crescent seen around Antarctica in this beautiful image certainly evokes a feeling of fragility and reminds us of our special place in space.
The image was taken by the OSIRIS camera on Rosetta about two hours before closest approach during the 13 November 2007 flyby, when the spacecraft was 75 000 km from Earth. The mission went on to become the first to rendezvous with and land on a comet, and the first to follow and study a comet on its orbit around the Sun.
Credits: ESA ©2005 MPS for OSIRIS Team MPS/UPD/LAM/IAA/RSSD/INTA/ UPM/DASP/IDA
The NASA/ESA Hubble Space Telescope has captured a monster in the making in this observation of the exceptional galaxy cluster eMACS J1353.7+4329, which lies about eight billion light-years from Earth in the constellation Canes Venatici. This disturbed collection of at least two galaxy clusters is in the process of merging together to create a cosmic monster, a single gargantuan cluster acting as a gravitational lens.
Gravitational lensing is a dramatic example of Einstein’s general theory of relativity in action. A celestial body such as a galaxy cluster is sufficiently massive to distort spacetime, which causes the path of light around the object to be visibly bent as if by a vast lens. Gravitational lensing can also magnify distant objects, allowing astronomers to observe objects that would otherwise be too faint and too far away to be detected. It can also distort the images of background galaxies, turning them into streaks of light. The first hints of gravitational lensing are already visible in this image as bright arcs which mingle with the throng of galaxies in eMACS J1353.7+4329.
The data in this image are drawn from an observing proposal called Monsters in the Making, which used two of Hubble’s instruments to observe five exceptional galaxy clusters at multiple wavelengths. These multi-wavelength observations were made possible by Hubble’s Wide Field Camera 3 and Advanced Camera for Surveys. The astronomers behind these observations hope to lay the groundwork for future studies of vast gravitational lenses with next-generation telescopes such as the NASA/ESA/CSA James Webb Space Telescope.
[Image Description: A cluster of elliptical galaxies, visible as a dense crowd of oval shapes, each glowing orange around a bright core. Right of the largest, central galaxy, a background galaxy is stretched into two connected, thin arcs by the cluster’s gravity. Various other galaxies are dotted all around, a few being small spirals. A bright star with four long spikes stands out at the right.]
Credits: ESA/Hubble & NASA, H. Ebeling; CC BY 4.0
A powerful combination of tectonic activity and strong winds have joined forces to shape the scenery in this region of Mars.
The image was taken by ESA’s Mars Express on 7 July 2015 and covers part of the Aeolis Mensae region. It straddles the transitional region between the southern hemisphere highlands and the smooth, northern hemisphere lowlands.
Credits: ESA/DLR/FU Berlin, CC BY-SA 3.0 IGO
Full story and high res photo: www.esa.int/spaceinimages/Images/2016/02/Aeolis_Mensae
This Copernicus Sentinel-2 image shows a snow-blanketed Berlin, taken on 31 January 2021.
Tiergarten, one of the city's biggest parks, can be seen in the city center, south of the Spree river.
Credits: contains modified Copernicus Sentinel data (2020), processed by ESA, CC BY-SA 3.0 IGO
Pictured here is the captivating galaxy NGC 2525. Located nearly 70 million light-years from Earth, this galaxy is part of the constellation of Puppis in the southern hemisphere. Together with the Carina and the Vela constellations, it makes up an image of the Argo from ancient greek mythology.
Another kind of monster, a supermassive black hole, lurks at the centre of NGC 2525. Nearly every galaxy contains a supermassive black hole, which can range in mass from hundreds of thousands to billions of times the mass of the Sun.
Hubble has captured a series of images of NGC2525 as part of one of its major investigations; measuring the expansion rate of the Universe, which can help answer fundamental questions about our Universe’s very nature. ESA/Hubble has now published a unique timelapse of this galaxy and it’s fading supernova.
Credits: ESA/Hubble & NASA, A. Riess and the SH0ES team; CC BY 4.0
Acknowledgment: Mahdi Zamani
In this image the NASA/ESA Hubble Space Telescope peers into the spiral galaxy NGC 1317 in the constellation Fornax, more than 50 million light-years from Earth. This galaxy is one of a pair, but NGC 1317’s rowdy larger neighbour NGC 1316 lies outside Hubble’s field of view. Despite the absence here of its neighbouring galaxy, NGC 1317 is accompanied in this image by two objects from very different parts of the Universe. The bright point ringed with a criss-cross pattern is a star from our own galaxy surrounded by diffraction spikes, whereas the redder elongated smudge is a distant galaxy lying far beyond NGC 1317.
The data presented in this image are from a vast observing campaign of hundreds of observations from Hubble’s Wide Field Camera 3 and Advanced Camera for Surveys. Combined with data from the ALMA array in the Atacama desert, these observations help astronomers chart the connections between vast clouds of cold gas and the fiercely hot young stars that form within them. ALMA’s unparalleled sensitivity at long wavelengths identified vast reservoirs of cold gas throughout the local Universe, and Hubble’s sharp vision pinpointed clusters of young stars, as well as measuring their ages and masses.
Often the most exciting astronomical discoveries require this kind of telescope teamwork, with cutting-edge facilities working together and providing astronomers with information across the electromagnetic spectrum. The same applies to future telescopes, with Hubble’s observations laying the groundwork for future science with the NASA/ESA/CSA James Webb Space Telescope.
Credits: ESA/Hubble & NASA, J. Lee and the PHANGS-HST Team; CC BY 4.0
This star-studded image from the NASA/ESA Hubble Space Telescope depicts NGC 6717, which lies more than 20 000 light-years from Earth in the constellation Sagittarius. NGC 6717 is a globular cluster, a roughly spherical collection of stars tightly bound together by gravity. Globular clusters contain more stars in their centres than their outer fringes, as this image aptly demonstrates; the sparsely populated edges of NGC 6717 are in stark contrast to the sparkling collection of stars at its centre.
The centre of the image also contains some interlopers from closer to home. Bright foreground stars close to Earth are surrounded by criss-cross diffraction spikes formed by starlight interacting with the structures supporting Hubble’s secondary mirror.
The area of the night sky which contains the constellation Sagittarius also contains the centre of the Milky Way, which is filled with light-absorbing gas and dust. This absorption of light — which astronomers refer to as extinction — makes studying globular clusters near the Galactic centre a challenging endeavour. To determine the properties of NGC 6717, astronomers relied on a combination of Hubble’s Wide Field Camera 3 and the Advanced Camera for Surveys.
Credits: ESA/Hubble and NASA, A. Sarajedini; CC BY 4.0
With giant storms, powerful winds, aurorae, and extreme temperature and pressure conditions, Jupiter has a lot going on. Now, the NASA/ESA/CSA James Webb Space Telescope has captured new images of the planet. Webb’s Jupiter observations will give scientists even more clues to Jupiter’s inner life.
In this wide-field view, Webb sees Jupiter with its faint rings, which are a million times fainter than the planet, and two tiny moons called Amalthea and Adrastea. The fuzzy spots in the lower background are likely galaxies “photobombing” this Jovian view.
This is a composite image from Webb’s NIRCam instrument (two filters) and was acquired on 27 July 2022.
For a version without annotations, click here.
For the closeup click here.
Credits: NASA, ESA, Jupiter ERS Team; image processing by Ricardo Hueso (UPV/EHU) and Judy Schmidt
Webb's picture of the month December is dominated by NGC 7469, a luminous, face-on spiral galaxy approximately 90 000 light-years in diameter that lies roughly 220 million light-years from Earth in the constellation Pegasus.
This spiral galaxy has recently been studied as part of the Great Observatories All-sky LIRGs Survey (GOALS), which aims to study the physics of star formation, black hole growth, and feedback in four nearby, merging luminous infrared galaxies. Other galaxies studied as part of the survey include previous ESA Webb Pictures of the Month II ZW 096 and IC 1623.
NGC 7469 is home to an active galactic nucleus (AGN), which is an extremely bright central region that is dominated by the light emitted by dust and gas as it falls into the galaxy’s central black hole. This galaxy provides astronomers with the unique opportunity to study the relationship between AGNs and starburst activity because this particular object hosts an AGN that is surrounded by a starburst ring at a distance of a mere 1500 light-years. While NGC 7469 is one of the best studied AGNs in the sky, the compact nature of this system and the presence of a great deal of dust have made it difficult for scientists to achieve both the resolution and sensitivity needed to study this relationship in the infrared. Now, with Webb, astronomers can explore the galaxy’s starburst ring, the central AGN, and the gas and dust in between.
Using Webb’s MIRI, NIRCam and NIRspec instruments to obtain images and spectra of NGC 7469 in unprecedented detail, the GOALS team has uncovered a number of details about the object. This includes very young star-forming clusters never seen before, as well as pockets of very warm, turbulent molecular gas, and direct evidence for the destruction of small dust grains within a few hundred light-years of the nucleus — proving that the AGN is impacting the surrounding interstellar medium. Furthermore, highly ionised, diffuse atomic gas seems to be exiting the nucleus at roughly 6.4 million kilometres per hour — part of a galactic outflow that had previously been identified from the ground, but is now revealed in stunning detail with Webb. With analysis of the rich Webb datasets still underway, additional secrets of this local AGN and starburst laboratory are sure to be revealed.
A prominent feature of this image is the striking six-pointed star that perfectly aligns with the heart of NGC 7469. Unlike the galaxy, this is not a real celestial object, but an imaging artifact known as a diffraction spike, caused by the bright, unresolved AGN. Diffraction spikes are patterns produced as light bends around the sharp edges of a telescope. Webb has three struts, with two angled at 150 degrees from its vertical strut, and its primary mirror is composed of hexagonal segments that each contain edges for light to diffract against. Webb’s struts are designed so that their diffraction spikes partially overlap with those created by the mirrors. Both of these lead to Webb’s complex star pattern.
Credits: ESA/Webb, NASA & CSA, L. Armus, A. S. Evans
As we eagerly await the return of our Earth from Space programme next Friday, today the Copernicus Sentinel-3 mission shows us a rare, cloud-free view of Iceland captured on 14 August 2020.
The large, white area visible on the island is a national park that encompasses the Vatnajökull Glacier. Covering an area of around 8400 sq km with an average ice thickness of more than 900 m, Vatnajökull is not only classified as the biggest glacier in Iceland, but the biggest in Europe.
The white, circular patch in the centre of the country is Hofsjökull, the country’s third largest glacier and its largest active volcano. The elongated white area west of Hofsjökull is Langjökull, Iceland’s second largest ice cap.
Reykjavík, the capital and largest city of Iceland, is located on the Seltjarnarnes Peninsula, in southwest Iceland. In the top-left of the image, several sea ice swirls can be seen off the coast of Greenland.
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
This image from ESA’s Mars Express shows Utopia Planitia, a plain that fills one of three major basins in the northern hemisphere of Mars – Utopia – and has a diameter of 3 300 km.
This image comprises data gathered by Mars Express’ High Resolution Stereo Camera (HRSC) on 12 July 2021. The colour image 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.
The ground resolution is approximately 19 m/pixel and the images are centred at about 83°E/43°N. North is to the right.
Credits: ESA/DLR/FU Berlin, CC BY-SA 3.0 IGO
The twisting patterns created by the multiple spiral arms of NGC 2835 create the illusion of an eye. This is a fitting description, as this magnificent galaxy resides near the head of the southern constellation of Hydra, the water snake. This stunning barred spiral galaxy, with a width of just over half that of the Milky Way, is brilliantly featured in this image taken by the NASA/ESA Hubble Space Telescope. Although it cannot be seen in this image, a supermassive black hole with a mass millions of times that of our Sun is known to nestle in the very centre of NGC 2835 .
This galaxy was imaged as part of PHANGS-HST, a large galaxy survey with Hubble that aims to study the connections between cold gas and young stars in a variety of galaxies in the local Universe. Within NGC 2835, this cold, dense gas produces large numbers of young stars within large star formation regions. The bright blue areas, commonly observed in the outer spiral arms of many galaxies, show where near-ultraviolet light is being emitted more strongly , indicating recent or ongoing star formation.
Expected to image over 100 000 gas clouds and star-forming regions outside our Milky Way, this survey hopes to uncover and clarify many of the links between cold gas clouds, star formation and the overall shape and morphology of galaxies. This initiative is a collaboration with the international Atacama Large Millimeter/submillimeter Array (ALMA) and the European Southern Observatory's Very Large Telescope's MUSE instrument, through the greater PHANGS program (PI: E. Schinnerer).
Credits: ESA/Hubble & NASA, J. Lee, and the PHANGS-HST Team Acknowledgement: Judy Schmidt (Geckzilla); CC BY 4.0
The NASA/ESA Hubble Space Telescope has determined the size of the largest icy comet nucleus ever seen by astronomers.
This image sequence shows how the nucleus of Comet C/2014 UN271 (Bernardinelli-Bernstein) was isolated from a vast shell of dust and gas surrounding the solid icy nucleus. On the left is a photo of the comet taken by the NASA/ESA Hubble Space Telescope's Wide Field Camera 3 on 8 January 2022. A model of the coma (middle panel) was obtained by means of fitting the surface brightness profile assembled from the observed image on the left. This allowed for the coma to be subtracted, unveiling the point-like glow from the nucleus. Combined with radio telescope data, astronomers arrived at a precise measurement of the nucleus size. That's no small feat from something roughly 4.8 billion kilometres away. Though the nucleus is estimated to be as large as 135 kilometres across, it is so far away it cannot be resolved by Hubble. Its size is derived from its reflectivity as measured by Hubble. The nucleus is estimated to be as black as charcoal. The nucleus area is gleaned from radio observations.
Credits: NASA, ESA, Man-To Hui (Macau University of Science and Technology), David Jewitt (UCLA), Alyssa Pagan (STScI); CC BY 4.0
The port town of Fos-Sur-Mer, in the southern part of Bouches-du-Rhône, France, is featured in this image captured by Copernicus Sentinel-2. It is from here where the first Meteosat Third Generation Imager satellite set sail last week on its journey to Europe’s Spaceport in French Guiana.
Bouches-du-Rhône is the third most populated department in France. With its wild and varied landscape, it borders Vaucluse to the north, Gard to the west and Var to the east (with the Mediterranean Sea visible to the south).
Marseille, the second most populous city in France, has one of the largest container ports in the country. Facing Marseille, the Frioul archipelago is made of four islands: Pomègue, Ratonneau, Tiboulen, and If. In the lower centre of the image lies the Étang de Berre, a brackish water lagoon around 25 km northwest of Marseille.[RP1]
Fos-sur-Mer lies on the Golfe de Fos, an inlet of the Mediterranean’s Gulf of Lion, around 50 km from Marseille. Originally a small fishing village, the port town was transformed in the 1960s with the expansion of Marseille’s port and the construction of a major industrial area. It has since become the centre of Marseille’s traffic and container shipments.
It is from here where the Meteosat Third Generation Imager-1 (MTG-I1) satellite set sail on its 12 day voyage to Europe’s Spaceport in Kourou.
MTG-I1 is the first imaging satellite in the Meteosat Third Generation programme which will improve weather forecasting in both Europe and Africa. Designed as a follow-up to the Meteosat Second Generation series, the MTG programme will ensure the continuity of high-resolution weather monitoring beyond 2040.
It will comprise six satellites: four MTG-I and two sounding satellites, MTG-S.
MTG-I’s Lightning Imager will provide a new capability for European meteorological satellites, ensuring the continuous monitoring of more than 80% of the Earth disc for detecting lightning discharges taking place either between clouds or from cloud and ground.
Once the four-tonne satellite safely arrives in Kourou, final preparations for lift off will take approximately seven weeks. It is scheduled to be launched in December onboard an Ariane 5 rocket.
Follow more updates on the first Meteosat Third Generation satellite by following our Earth Observation Launch Campaign blog or on the MTG-I1 Pre-Launch Diary.
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
Lake Trasimeno, the fourth largest lake in Italy, is featured in this week’s Earth from Space image.
Lake Trasimeno is located in central Italy, around 20 km west of Perugia, and has an area of around 128 sq km. It is shallow, with its maximum depth of approximately 6 m, although the lake’s water level varies depending on meteorological and climatic conditions.
In this Copernicus Sentinel-2 image, captured on 6 August 2022, the lake’s emerald green colour is likely due to the presence of phytoplankton. Streaks in the water, particularly visible in the west, indicate the presence of soil and sediments which have been stirred up by winds. Dark coloured waters in the southern part of the lake indicate a presence of submerged and floating macrophytes (aquatic plants) as well as algae.
Surrounded by hills on three sides, Trasimeno is subject to heavy storms created by winds, especially from the north and west. There are three islets in the lake: Maggiore, Minore and Polvese (the largest). The lake’s shores are sparsely inhabited with only two popular villages: Castiglione del Lago and Passignano sul Trasimeno.
Italy is experiencing its worst drought in 70 years which has affected drinking water supplies, hydroelectric power and agricultural production. High temperatures, hot winds and lack of rainfall are the main causes of drought in the Umbrian region which saw Lake Trasimeno’s drop 1.3 m, reaching the limit of the hydrometric zero in July 2022.
Lake Trasimeno wasn’t the only Italian water body affected by drought this summer, with the Po River hitting record-lows. The Copernicus Sentinel-2 satellites capture high-resolution imagery that provides information about the conditions on Earth, such as water quality, plant life and coastal areas.
The mountainous terrain of the Umbrian Apennine Mountains surrounds Lake Trasimeno with many agricultural fields dotted around the area. Several other smaller lakes including Lake Montepulciano, Lake Chiusi and Lake Pietrafitta, can be seen south of Lake Trasimeno. Perugia, capital of the Umbria region, is a well-known cultural and artistic centre in Italy known for its chocolate and jazz festivals.
This image is also featured on our weekly Earth from Space video series.
Credits: contains modified Copernicus Sentinel data (2022), processed by ESA, CC BY-SA 3.0 IGO
A magnetic phenomenon known as solar switchbacks has been imaged by the ESA/NASA Solar Orbiter spacecraft for the first time.
The image zooms in on the switchback (blue/white feature extending towards the left) as captured in the solar corona by the Metis instrument on 25 March 2022. The switchback appears to be linked to the active region seen in the central Extreme Ultraviolet Imager image (right).
Click here for annotated version
Credits:ESA & NASA/Solar Orbiter/EUI & Metis Teams and D. Telloni et al. (2022)
This Copernicus Sentinel-2 image, captured on 28 December 2021, shows the location of the Zaap-C offshore platform with many other offshore platforms visible flaring in the area.
Please note that the water vapour columns are very typical on days when flaring is active. It is not the case for the days when the methane fluxes occur (on these days, there is neither flaring nor water vapour).
Credits: contains modified Copernicus Sentinel data (2021), processed by ESA,CC BY-SA 3.0 IGO
Italian ESA astronaut Samantha Cristoforetti poses in the Cupola module of the International Space Station with two 100-day patches to mark her 200th day in space. In 2022, she will return to her ‘home away from home’ for even more days in orbit.
Samantha first flew to the International Space Station on a Soyuz spacecraft in 2014 for a mission known as ‘Futura’. Her second flight follows the second missions of her fellow 2009 astronaut classmates Alexander Gerst in 2018, Luca Parmitano in 2019 and Thomas Pesquet in 2021. It could also see a direct on-Station handover with Matthias Maurer who is scheduled to fly his first mission to the Space Station later this year. The spacecraft Samantha will fly on is not yet confirmed, but could be a SpaceX Crew Dragon or Boeing CST-100 Starliner.
During Futura, Samantha supported an extensive scientific programme of experiments in physical science, biology and human physiology as well as radiation research and technology demonstrations.
She also oversaw the undocking of ESA’s fifth and final Automated Transfer Vehicle (ATV). This marked the end of a successful programme that paved the way for the European Service Modules currently being produced for NASA’s Orion spacecraft that will travel around and to the Moon.
Training for Samantha’s second mission is already underway and has included International Space Station refresher sessions at ESA’s astronaut centre in Cologne, Germany, and NASA’s Johnson Space Center in Houston, Texas.
In the coming months, her schedule will intensify as she brushes up on Space Station systems and procedures and trains for the specific experiments and tasks she will perform in space.
More details of Samantha’s second mission will be announced during a virtual press briefing on Wednesday, 3 March, at 11:00 CET.
ESA is also in the process of recruiting its next class of astronauts. For more on the upcoming selection visit Your Way To Space.
Credits: ESA/NASA
The blue and orange stars of the faint galaxy named NGC 2188 sparkle in this image taken with the NASA/ESA Hubble Space Telescope. Although NGC 2188 appears at first glance to consist solely of a narrow band of stars, it is classified by astronomers as a barred-spiral galaxy. It appears this way from our viewpoint on Earth as the centre and spiral arms of the galaxy are tilted away from us, with only the very narrow outer edge of the galaxy’s disc visible to us. Astronomers liken this occurrence to turning a dinner plate in your hands so you see only its outer edge. The true shape of the galaxy was identified by studying the distribution of the stars in the inner central bulge and outer disc and by observing the stars’ colours.
NGC 2188 is estimated to be just half the size of our Milky Way, at 50 000 light-years across, and it is situated in the northern hemisphere constellation of Columba (The Dove). Named in the late 1500s after Noah’s dove in biblical stories, the small constellation consists of many faint yet beautiful stars and astronomical objects.
Credits: ESA/Hubble & NASA, R. Tully; CC BY 4.0
Skygazers across the Northern Hemisphere are being treated to stunning views of comet NEOWISE as it streaks past Earth. Amateur astrophotographer Javier Manteca got a bonus: the International Space Station and the comet are both seen transiting Madrid in this photo captured 11 July.
Taken at dawn, the picture is a composition of 17 stacked images exposed every 2.5 seconds to form the skyline.
Comet C/2020 F3 NEOWISE is named after NASA’s Near-Earth Object Wide-field Infrared Survey Explorer mission that discovered it in March 2020. The comet completed its perihelion, or closest pass of the Sun, on 3 July and is headed back out of our Solar System, not to return for another 6800 years.
Comets are the icy remnants from the formation of the planets 4.6 billion years ago, prompting scientists to think of them as cosmic time capsules. Comets have distinctive tails caused by dust grains being swept away from the comet’s nucleus.
The comet's flyby of Earth is a rare opportunity to observe and collect data on these cosmic time capsules. Many spacecraft have observed the comet, including the ESA/NASA Solar and Heliospheric Observatory as well as astronauts on board the International Space Station.
ESA’s comet chaser Rosetta trailed comet 67P/Churyumov–Gerasimenko for two years before landing the Philae probe on its surface. The mission amassed a wealth of data that will be studied for years to come.
As comet NEOWISE zooms past Earth at a comfortable (and safe) distance of 103 million kilometres, stargazers can catch more views of the comet through July. Consult Earth and Sky or Astronomy Now for times and positions.
Credits: Javier Manteca
A massive galaxy cluster in the constellation Cetus dominates the centre of this image from the NASA/ESA Hubble Space Telescope. This image is populated with a serene collection of elliptical and spiral galaxies, but galaxies surrounding the central cluster — which is named SPT-CL J0019-2026 — appear stretched into bright arcs, as if distorted by a gargantuan magnifying glass. This cosmic contortion is called gravitational lensing, and it occurs when a massive object like a galaxy cluster has a sufficiently powerful gravitational field to distort and magnify the light from background objects. Gravitational lenses magnify light from objects that would usually be too distant and faint to observe, and so these lenses can extend Hubble’s view even deeper into the Universe.
This observation is part of an ongoing project to fill short gaps in Hubble’s observing schedule by systematically exploring the most massive galaxy clusters in the distant Universe, in the hopes of identifying promising targets for further study with both Hubble and the NASA/ESA/CSA James Webb Space Telescope. This particular galaxy cluster lies at a vast distance of 4.6 billion light years from Earth.
Each year, the Space Telescope Science Institute is inundated with observing proposals for Hubble, in which astronomers suggest targets for observation. Even after selecting only the very best proposals, scheduling observations of all of Hubble’s targets for a year is a formidable task. There is sometimes a small fraction of observing time left unused in Hubble’s schedule, so in its ‘spare time’ the telescope has a collection of objects to explore — including the lensing galaxy cluster shown in this image.
[Image description: A cluster of large galaxies, surrounded by various stars and smaller galaxies on a dark background. The central cluster is mostly made of bright elliptical galaxies that are surrounded by a warm glow. Nearby the cluster is the stretched, distorted arc of a galaxy, gravitationally lensed by the cluster.]
Credits: ESA/Hubble & NASA, H. Ebeling; CC BY 4.0
Believe it or not, this long, luminous streak, speckled with bright blisters and pockets of material, is a spiral galaxy like our Milky Way. But how could that be?
It turns out that we see this galaxy, named NGC 3432, orientated directly edge-on to us from our vantage point here on Earth. The galaxy’s spiral arms and bright core are hidden, and we instead see the thin strip of its very outer reaches. Dark bands of cosmic dust, patches of varying brightness, and pink regions of star formation help with making out the true shape of NGC 3432 — but it’s still somewhat of a challenge! Because observatories such as the NASA/ESA Hubble Space Telescope have seen spiral galaxies at every kind of orientation, astronomers can tell when we happen to have caught one from the side.
The galaxy is located in the constellation of Leo Minor (The Lesser Lion). Other telescopes that have had NGC 3432 in their sights include those of the Sloan Digital Sky Survey, the Galaxy Evolution Explorer (GALEX), and the Infrared Astronomical Satellite (IRAS).
Credits: ESA/Hubble & NASA, A. Filippenko, R. Jansen; CC BY 4.0
To celebrate the recent data release from Landsat 9, this week we take a closer look at a part of Washington state – the northwesternmost state of the US – through the lens of Landsat 9.
Data from Landsat 9, which was launched in September 2021, is now publicly available for users and researchers across the world. The satellite will continue the programme’s critical role in monitoring, understanding and managing the land resources needed to sustain human life.
A partnership between NASA and the US Geological Survey, the satellite carries two science instruments, the Operational Land Imager 2 (OLI-2) and the Thermal Infrared Sensor 2 (TIRS-2). The OLI–2 captures observations of the Earth’s surface in visible, near-infrared, and shortwave-infrared bands, and TIRS-2 measures thermal infrared radiation, or heat, emitted from Earth’s surface.
This false-colour image, captured on 12 February 2022 by Landsat 9, has been processed using the satellite’s near-infrared channel. This channel is frequently used to highlight vegetation, which is particularly evident in the lower half of the image. Fields that are currently cultivated can be seen in bright red, while unvegetated areas appear in green and brown. Circular shapes, predominantly in the bottom-left, are centre-pivot irrigation fields – where equipment rotates around a central pivot and crops are watered with sprinklers. Washington is a leading agricultural state, with the top crops being apples, milk, potatoes and wheat.
Columbia River, the largest river in the Pacific Northwest, is visible in the top of the image in black. The river rises in the Rocky Mountains of British Columbia, Canada, flows through Washington and Oregon, before emptying into the Pacific Ocean. The river is one of the world’s greatest sources of hydroelectric power and, with its tributaries, represents a third of the potential hydropower of the United States.
As water absorbs a fair amount of radiation, water bodies, such as the Columbia River, appear black in the image. However certain icy water bodies dotted in the left of the image can be seen in turquoise as ice reflects less in the near-infrared channel than in the visible part of the spectrum.
The Landsat series is part of ESA’s Third-Party Missions programme which consists of almost 50 satellite missions, and also forms part of ESA’s Heritage Space programme.
This image is also featured on the Earth from Space video programme.
Credits: USGS/NASA Landsat/ESA
The Copernicus Sentinel-2 mission takes us over part of the northern coast of the Pilbara region in Western Australia.
As the image shows, the coast is a complex system of deltas, limestone barrier islands, salt ponds and lagoons.
Captured on 5 March 2023 and processed in false-colour, the image offers information on vegetation. The processing involved using the mission’s near-infrared channel to help highlight the distribution, density and health of the vegetation in red. The healthier the plants are, the brighter red they appear.
On the left, tidal channels and mangroves are also visible in red. Mangroves play an important role in preventing erosion and protecting the coastline from waves and storms.
Round islands can be seen in the coastal lagoons. These are in contrast to the rectangular, white and blue ponds of the salt extraction industry in the Onslow Salt Lake to the east. Causeways divide the lake into three zones which help with the evaporation process.
North of the lake lies the coastal city of Onslow, with its airport clearly visible to the south of the city.
In the bottom centre of the image, numerous catchments that collect water after rain are visible in gold – gold partly due to the presence of mud.
Off the coast, a number of islands are scattered in the dark blue Indian Ocean waters. Their red appearance means that they are covered in vegetation. In fact, Pilbara islands are home to various nature reserves. Thevenard Island, the bigger island in the centre top of the image, is important for a wealth of marine wildlife such as sea turtles, dolphins, whales and fish.
Credits: contains modified Copernicus Sentinel data (2023), processed by ESA, CC BY-SA 3.0 IGO
This image shows the orbits of the more than 150 000 asteroids in Gaia’s data release 3, from the inner parts of the Solar System to the Trojan asteroids at the distance of Jupiter, with different colour codes.
The yellow circle at the centre represents the Sun. Blue represents the inner part of the Solar System, where the Near Earth Asteroids, Mars crossers, and terrestrial planets are. The Main Belt, between Mars and Jupter, is green. Jupiter trojans are red.
Credits: ESA/Gaia/DPAC; CC BY-SA 3.0 IGO
Although it looks more like an entity seen through a microscope than a telescope, this rounded object, named NGC 2022, is certainly no alga or tiny, blobby jellyfish. Instead, it is a vast orb of gas in space, cast off by an ageing star. The star is visible in the orb's centre, shining through the gases it formerly held onto for most of its stellar life.
When stars like the Sun grow advanced in age, they expand and glow red. These so-called red giants then begin to lose their outer layers of material into space. More than half of such a star's mass can be shed in this manner, forming a shell of surrounding gas. At the same time, the star's core shrinks and grows hotter, emitting ultraviolet light that causes the expelled gases to glow.
This type of object is called, somewhat confusingly, a planetary nebula, though it has nothing to do with planets. The name derives from the rounded, planet-like appearance of these objects in early telescopes.
NGC 2022 is located in the constellation of Orion (The Hunter).
Credits: ESA/Hubble & NASA, R. Wade; CC BY 4.0
At around 60 million light-years from Earth, the Great Barred Spiral Galaxy NGC 1365 is captured beautifully in this image by the NASA/ESA Hubble Space Telescope. Located in the constellation of Fornax (The Furnace), the blue and fiery orange swirls show us where stars have just formed and the dusty sites of future stellar nurseries.
At the outer edge of the image, enormous star-forming regions within NGC 1365 can be seen. The bright, light-blue regions indicate the presence of hundreds of baby stars that formed from coalescing gas and dust within the galaxy's outer arms.
This Hubble image was captured as part of a joint survey with the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile. The survey will help scientists understand how the diversity of galaxy environments observed in the nearby Universe, including NGC 1365 and previous ESA/Hubble Pictures of the Week such as NGC 2835 and NGC 2775, influence the formation of stars and star clusters. Expected to image over 100 000 gas clouds and star-forming regions beyond our Milky Way, the PHANGS survey is expected to uncover and clarify many of the links between cold gas clouds, star formation and the overall shape and morphology of galaxies.
Credits: ESA/Hubble & NASA, J. Lee and the PHANGS-HST Team; CC BY 4.0
- Acknowledgement: Judy Schmidt (Geckzilla)
This image – combined of many exposures – captures 'totality' during the 2 July 2019 total solar eclipse, the moment that the Moon passes directly in front of the Sun from Earth's perspective, blocking out its light and allowing the Sun's extended atmosphere – the corona – to be seen. The processing of this image highlights the intricate detail of the corona, its structures shaped by the Sun's magnetic field. Some details of the lunar surface can also be seen. The image was created by the ESA-CESAR team observing the eclipse from ESO's La Silla Observatory in Chile, South America.
Credits: ESA/CESAR
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
11 December is International Mountain Day and to commemorate this day, the Copernicus Sentinel-2 satellite flies over Mount Everest, the highest mountain on Earth.
Mount Everest is part of a region known as "third pole", since the high-altitude ice fields in this area contain the largest reserve of freshwater outside the polar regions.
With such a large portion of the world’s population dependent on water from these cold heights, changes in the size and flow of these glaciers can bring serious consequences for society by affecting the amount of water arriving downstream. From the vantage point of space, satellites, such as the Copernicus Sentinels, provide essential information to monitor the changing face of Earth’s glaciers, which are typically in remote regions and therefore difficult to monitor systematically from the ground.
Credits: contains modified Copernicus Sentinel data (2021), processed by ESA, CC BY-SA 3.0 IGO
On 11 March 2022, the James Webb Space Telescope (Webb) team completed the stage of mirror alignment known as "fine phasing". Although there are months to go before Webb ultimately delivers its new view of the cosmos, achieving this milestone means the team is confident that Webb’s first-of-its-kind optical system is working as well as possible.
At this key stage in the commissioning of Webb’s Optical Telescope Element, every optical parameter that has been checked and tested is performing at, or above, expectations. The team also found no critical issues and no measurable contamination or blockages to Webb’s optical path: the observatory is able to successfully gather light from distant objects and deliver it to its instruments without issue. At this stage of Webb’s mirror alignment, each of the primary mirror segments has been adjusted to produce one unified image of the same star using only Webb’s primary imager, the Near-Infrared Camera (NIRCam), and NIRCam has been fully aligned to the observatory's mirrors.
While the purpose of this image was to focus on the bright star at the centre (called 2MASS J17554042+6551277) for alignment evaluation, Webb's optics and NIRCam are so sensitive that galaxies and stars in the background also show up. This image uses a red filter to optimise visual contrast.
Credits: NASA/STScI
This eerie coloured orb is nothing less than the life-giver of the Solar System. It is the Sun, the prodigious nuclear reactor that sits at the heart of our planetary system and supplies our world with all the light and heat needed for us to exist.
This image was taken by SOHO's (Solar & Heliospheric Observatory) extreme-ultraviolet telescope. This telescope is sensitive to four wavelengths of extreme-ultraviolet light, and the three shortest were used to build this image. Each wavelength has been colour-coded to highlight the different temperatures of gas in the Sun.
Credit: SOHO (ESA & NASA)
Read more about the colours in this image here.
Resting on the tail of the Great Bear in the constellation of Ursa Major, lies NGC 5585, a spiral galaxy that is more than it appears.
The many stars, and dust and gas clouds that make up NGC 5585, shown here in this Hubble image, contribute only a small fraction of the total mass of the galaxy. As in many galaxies, this discrepancy can be explained by the abundant yet seemingly invisible presence of dark matter.
The stellar disc of the galaxy extends over 35 000 light-years across. When compared with galaxies of a similar shape and size, NGC 5585 stands out by having a notably different composition: Contributing to the total mass of the galaxy, it contains a far higher proportion of dark matter.
Hotspots of star formation can be seen along the galaxy’s faint spiral arms. These regions shine a brilliant blue, contrasting strikingly against the ever-black background of space.
Credits: ESA/Hubble & NASA, R. Tully; CC BY 4.0
Acknowledgement: Gagandeep Anand
This NASA/ESA Hubble Space Telescope image of the asteroid Dimorphos was taken on 19 December 2022, nearly four months after the asteroid was impacted by NASA’s DART (Double Asteroid Redirection Test) mission. Hubble’s sensitivity reveals a few dozen boulders knocked off the asteroid by the force of the collision. These are among the faintest objects Hubble has ever photographed inside the Solar System. The ejected boulders range in size from 1 m to 6.7 m across, based on Hubble photometry. They are drifting away from the asteroid at around 1 km per hour. The discovery yields invaluable insights into the behaviour of a small asteroid when it is hit by a projectile for the purpose of altering its trajectory.
[Image Description: The bright white object at lower left is the asteroid Dimorphos. It has a blue dust tail extending diagonally to the upper right. A cluster of blue dots surrounds the asteroid. These are boulders that were knocked off the asteroid when, on 26 September 2022, NASA deliberately slammed the half-tonne DART impactor spacecraft into the asteroid as a test of what it would take to deflect some future asteroid from hitting Earth. Hubble photographed the slow-moving boulders in December 2022.]
Credits: NASA, ESA, D. Jewitt (UCLA); CC BY 4.0
An odd-shaped formation of gas and dust at the centre of the Milky Way, captured by the far-infrared cameras on board ESA’s Herschel space observatory. The nearly continuous strip of dense and cold clumps of material forms an infinity symbol, or sideways 8, that is a few hundred light years across. In this image, the strip twists around an invisible axis running roughly from the top left to the bottom right.
The infinity-shaped loop, estimated to have a whopping 30 million solar masses, is made up of dense gas and dust at a temperature of just 15 degrees above absolute zero. Displayed in yellow in the image, it contrasts with warmer, less dense gas and dust from the centre of the Galaxy that appears inside the strip and is coloured in blue. Surrounding the loop is cool gas, painted in red-brownish tones.
The ring and its surroundings harbour a number of star-forming regions and young stars, which stand out in bright-blue colour in the image. The area is part of the Central Molecular Zone, a region at the centre of the Milky Way permeated with molecular clouds, which are ideal sites for star formation.
The Galactic Centre is located almost 30,000 light years away from the Sun, in the direction of the Sagittarius constellation. It is a complex and dynamic place, with emission nebulae and supernova remnants – in addition to star-forming molecular clouds – surrounding the supermassive black hole that sits at our Galaxy’s core. The gas and dust in this region appears mostly dark when viewed through an optical telescope, but it can be seen clearly with Herschel’s instruments.
This image was captured by the Herschel’s PACS (Photodetector Array Camera and Spectrometer) and SPIRE (Spectral and Photometric Imaging REceiver) far-infrared cameras, and it was first published in 2011. Obtained as part of Hi-GAL, the Herschel infrared Galactic Plane Survey, it combines observations at three different wavelengths: 70 microns (blue), 160 microns (green) and 250 microns (red).
Herschel was an ESA space observatory active from 2009 to 2013. At the time of its launch, it had the largest telescope ever sent into space.
Credits: ESA / NASA / JPL-Caltech / Hi-GAL
Space Science image of the week:
Thanks to a quirk of our cosmos, the Moon’s average distance from Earth is just right for it to appear as the same size in the sky as the significantly larger Sun. Once in a while the Moon slides directly between Earth and the Sun such that it appears to cover our star completely, temporarily blocking out its light and creating a total solar eclipse for those along the narrow path cast by the Moon’s shadow.
Next week, on 21 August, observers situated along a 115 km-wide swath stretching from Oregon to South Carolina in the US will be on this path of totality, with peak totality occurring at 18:26 GMT (check here for detailed timings). For up to 2 minutes 40 seconds, observers at a given location will be bathed in an eerie twilight in the middle of the day.
It is not possible to view totality from Europe, although those in the westernmost region may see a partial eclipse before the Sun drops below the horizon at sunset.
A team of astronomers from ESA will be studying the eclipse from the USA and, like many others, hoping that skies will be clear so that they can capture the phenomena visible only during eclipses. These include beads of light shining through gaps in the lunar terrain, and the glittering ‘diamond ring’ effect as the last and first slither of sunlight glints through immediately before and after totality.
They will also aim to image the Sun’s extended atmosphere, the corona, which is visible to the naked eye only during totality when the rest of the Sun’s light is blocked out.
Observations of the corona are business as usual for the ESA/NASA Solar and Heliospheric Observatory, SOHO, which can use a special filter to block the Sun’s light. During Earth’s total eclipse, SOHO will provide important context of the corona and Sun’s activity from its viewpoint in space.
Outside of the path of totality observers will experience a partial eclipse – seeing the Moon appear to take a bite out of the Sun’s disc. This is similar to what our Proba-2 satellite will see – an example is shown in the image presented here, which was taken during the annular eclipse earlier this year. It shows the turbulent solar disc and swirling corona at extreme-ultraviolet wavelengths.
In fact, Proba-2 will see a series of partial eclipses from Earth orbit. Proba-2 orbits Earth about 14.5 times per day, and thanks to the constant change in viewing angle, will dip in and out of the Moon’s shadow several times during the solar eclipse.
In addition, astronauts aboard the International Space Station, including ESA’s Paolo Nespoli, should also be able to see some aspects of the eclipse. From their unique vantage point, they will view partial eclipses and also hope to capture the Moon’s shadow on the surface of our planet.
Follow ESA’s ground-based activities via cesar.esa.int and join the conversation on Twitter with #eclipse2017 and #solareclipse. We’ll keep you posted on our activities – from ground and space – via @esascience.
Remember: never look directly at the Sun, even when partially eclipsed, without proper eye protection such as special solar eclipse glasses, or you risk permanent eye damage.
Credit: ESA/Royal Observatory of Belgium
During spring and summer, as the air warms up and the sun beats down on the Greenland Ice Sheet, melt ponds pop up. Melt ponds are vast pools of open water that form on both sea ice and ice sheets and are visible as turquoise-blue pools of water in this Copernicus Sentinel-2 image.
When snow and ice melts atop glaciers, water flows in channels and streams and collects in depressions on the surface. These melt ponds can speed up the melting of the surrounding ice since they greatly reduce the ice’s ability to reflect sunlight. This can create a positive feedback where an increasing number of melt ponds absorb more heat which causes ice cover to melt even faster. In this image, captured on 29 August 2022, melt ponds in the province of Avannaata can be easily spotted from space as they are usually much darker than the surrounding ice. In some ponds, chunks of ice float atop the pond’s waters.
The bay visible here is Sugar Loaf Bay (an indentation of the northeast Baffin Bay) in the Upernavik Archipelago. The archipelago extends from the northwest coast of Sigguup Nunaa peninsula to the southern end of Melville Bay.
The Greenland Ice Sheet is the largest ice mass in the northern hemisphere. It extends 2220 km north-south with an average thickness of around 1500 m and spans 1100 km at its widest point.
As most of the northern hemisphere baked under a prolonged heatwave this summer, Greenland has been hit with an unusual late-season heatwave and melt event in early September – the kind of melt that usually occurs in the middle of summer.
The first day of September typically marks the end of the Greenland melt season, as the sun moves lower in the sky with temperatures usually cooling. However, at the beginning of September 2022, temperatures began to rise again when a strong air pressure region parked at the southeast edge of Greenland and drew warmer air northwards across Baffin Bay and the west coast of Greenland.
This led to meltwater runoff, the amount of surface water entering the ocean, to increase with its extensive melting contributing to global sea level rise – which impacts the millions of people living in coastal communities.
In a recent paper published in Nature Climate Change, scientists found that major sea-level rise from the melting of the Greenland ice cap is now ‘inevitable’ even if the burning of fossil fuels were to halt overnight. Using satellite observations of Greenland ice loss and ice cap from 2000 to 2019, the team found the losses will lead to a minimum rise of 27 cm regardless of climate change.
Earth observation satellites are key to monitoring ice as they carry instruments that measure changes in the thickness of the ice sheets, fluctuations in the speed of the outlet glaciers and even small changes in Earth’s gravity field caused by melting ice as well as sea-level rise.
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
Data from more than 1.8 billion stars has been used to create this map of the entire sky. It shows the total brightness and colour of stars observed by ESA’s Gaia satellite and released as part of Gaia’s Early Data Release 3 (Gaia EDR3).
Brighter regions represent denser concentrations of bright stars, while darker regions correspond to patches of the sky where fewer and fainter stars are observed. The colour of the image is obtained by combining the total amount of light with the amount of blue and red light recorded by Gaia in each patch of the sky.
The bright horizontal structure that dominates the image is the plane of our Milky Way galaxy. It is actually a flattened disc seen edge-on that contains most of the galaxy’s stars. In the middle of the image, the Galactic centre appears bright, and thronged with stars.
Darker regions across the Galactic plane correspond to foreground clouds of interstellar gas and dust, which absorb the light of more distant stars. Many of these clouds conceal stellar nurseries where new generations of stars are currently being born.
Dotted across the image are also many globular and open clusters, as well as entire galaxies beyond our own. The two bright objects in the lower right of the image are the Large and Small Magellanic Clouds, two dwarf galaxies orbiting the Milky Way.
Gaia EDR3 was made public on 3 December 2020 and includes the position and brightness of more than 1.8 billion stars, the parallax and proper motion of almost 1.5 billion stars, and the colour of more than 1.5 billion stars. It also includes more than 1.6 million extragalactic sources.
A complementary image showing Gaia's density map of the stars is available here.
Gaia's all-sky colour view is also available in equirectangular projection (suitable for full-dome presentations) here.
Credits: ESA/Gaia/DPAC; CC BY-SA 3.0 IGO. Acknowledgement: A. Moitinho and M. Barros
ESA astronaut Thomas Pesquet snapped this image of Normandy from the International Space Station during his second long-duration mission known as Alpha. He posted it on social media saying "The Space Station always travels from West to East, which is great for taking pictures of my birthplace Normandy. A perfect frame to start the Earth pictures of #MissionAlpha "
Thomas was launched to the International Space Station for his second mission, Alpha, on 23 April 2021. He will spend six months living and working on the orbital outpost where he will support more than 200 international experiments in space.
Follow Thomas and his Mission Alpha on his blog.
Credits: ESA/NASA–T. Pesquet
This image shows the irregular galaxy NGC 6822, which was observed by the Near-InfraRed Camera (NIRCam) and Mid-InfraRed Instrument (MIRI) mounted on the NASA/ESA/CSA James Webb Space Telescope. As their names suggest, NIRCam and MIRI probe different parts of the electromagnetic spectrum. This allows the instruments to observe different components of the same galaxy, with MIRI especially sensitive to its gas-rich regions (the yellow swirls in this image) and NIRCam suitable for observing its densely packed field of stars.
NGC 6822 lies about 1.5 million light-years away, and is the Milky Way’s nearest galactic neighbour that is not one of its satellites. It has a very low metallicity, meaning that it contains very low proportions of elements that are not hydrogen and helium. Metallicity is an absolutely key concept in astronomy, in part because elements other than hydrogen and helium are largely produced by stars over their lifetimes. Therefore, in the very early Universe (before the first generation of stars had been born, lived and died) everything had very low metallicity. This makes contemporary low-metallicity objects (like NGC 6822) objects of interest for understanding how processes such as the evolution of stars and the life cycle of interstellar dust likely occurred in the early Universe. This was the motivation for these observations of NGC 6822 with Webb: to better understand how stars form and how dust evolves in low-metallicity environments.
The study of NGC 6822 has an interesting history that long predates modern investigations with Webb. It was first discovered by E. E. Barnard, who presented his discovery in a very brief paper in 1884 in The Sidereal Messenger: a short-lived but important American monthly astronomical journal that was published between 1882 and 1891. As with many astronomical objects that appeared diffuse with telescopes of the time, NGC 6822 was miscategorised as an "exceedingly faint nebula".
Over the next few years, a series of confusions arose around NGC 6822 over its apparent size, brightness, and even what kind of object it was, because astronomers at the time did not properly account for how different the same object might look with different telescopes. Edwin Hubble, namesake of the NASA/ESA Hubble Space telescope, went on to study NGC 6822 in depth and published a far more detailed paper of his own in 1925. This work was exceptionally important for humanity’s evolving understanding of the Universe, because, in Hubble’s own words: "N.G.C. 6822, [was] the first object definitely assigned to a region outside the galactic system". This paper contributed to solving the debate that was raging amongst astronomers about the extent of the Universe at the time by demonstrating that there were astronomical objects that lay beyond the Milky Way. The study of this galaxy was notably continued by Susan Keyser, who was the first woman to receive a PhD in astronomy from Caltech. Her 1966 thesis remained the most thorough investigation of this galaxy until the 2000s. Now, the study of this key local galaxy is being continued by Webb.
[Image Description: A dense field of stars with clouds of gas and dust billowing across it. The clouds are patchy and wispy, dense and glowing parts obscuring the centre of the image. Bright galaxies with various shapes and sizes shine through the gas and stars. Some of the star images are a bit larger than the rest, with visible diffraction spikes; two foreground stars are bright in the lower-right corner.]
Credits: ESA