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This image from ESA’s Mars Express shows a beautiful slice of the Red Planet from the northern polar cap downwards, and highlights cratered, pockmarked swathes of the Terra Sabaea and Arabia Terra regions. It comprises data gathered on 17 June 2019 during orbit 19550.
The ground resolution at the centre of the image is approximately 1 km/pixel and the images are centred at about 44°E/26°N. This image was created using data from the nadir and colour channels of the High Resolution Stereo Camera. The nadir channel is aligned perpendicular to the surface of Mars, as if looking straight down at the surface. North is up.
Credits: ESA/DLR/FU Berlin, CC BY-SA 3.0 IGO
The total solar eclipse of 2 July 2019, composed for viewing with red-green/blue '3D' anaglyph glasses. The image combines the first and last image during totality and has a subtle 3D effect.
Credits: ESA/CESAR
Part of the Laguna San Rafael National Park, located on the Pacific coast of southern Chile, is pictured in this image captured by the Copernicus Sentinel-2 mission.
Covering an area of around 17000 sq km, the park includes the Northern Patagonian Ice Field – a remnant of the Patagonian Ice Sheet that once covered the region. Today, despite the ice field being just a small fraction of its previous size, it is still the second largest continuous mass of ice outside of the polar regions.
The image depicts the west part of the Northern Patagonian Ice Field which has 28 exit glaciers, with the largest two, San Rafael and San Quintín, visible here. San Rafael Glacier, which can be seen in the upper-right of the image, is one of the most actively calving glaciers in the world and the fastest-moving glacier in Patagonia – ‘flowing’ at a speed of around 7.6 km per year.
The glacier calves west towards the Pacific Ocean and into the Laguna San Rafael (Lake San Rafael), visible directly to the left of the glacier. The lake was formed due to the retreat of the glacier after the last ice age, and today is a popular tourist destination, with ships sailing to the lagoon to see ice falling from the glacier.
Directly below lies the San Quintín glacier, the second-largest glacier in the northern ice field. The glacier drains to the west, where hundreds of icebergs can be seen dotted in the lake. Until 1991, the glacier terminated on land, but with its retreat, the basin filled with water and formed the proglacial lake we see today.
Together with its twin, San Rafael, the glaciers have been receding dramatically under the influence of global warming. Satellite data show that some of the glaciers in Patagonia are retreating faster than anywhere in the world. As temperatures rise and glaciers and ice sheets melt, the water eventually runs into the ocean, causing sea level to rise.
According to a report last year, glaciers worldwide have lost over 9000 gigatonnes of ice since 1961 – raising sea level by 27 mm. Rising seas are one of the most distinctive and potentially devastating effects of Earth’s warming climate.
For the last 30 years, a series of satellites have collected global sea level measurements to keep an eye on its rising trend. Scheduled for launch in November 2020, the Copernicus Sentinel-6 Michael Freilich satellite will be the next spacecraft to continue the long-term record of sea-surface height measurements started in 1992.
The satellite will collect the most accurate data on sea level and monitor how it changes over time. The satellite carries a radar altimeter, which works by measuring the time it takes for radar pulses to travel to Earth’s surface and back again to the satellite.
The spacecraft also carries five instruments to help monitor atmospheric conditions that affect the radar signal and to determine the precise position and velocity of the satellite in orbit. Other instruments measure atmospheric temperature and humidity profiles for weather forecasting and the radiation environment around the satellite.
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
These finely-detailed ceramic parts have been 3D printed using simulated lunar regolith as part of an ESA-led investigation into how 3D printing could be used to support a lunar base.
“These parts have the finest print resolution ever achieved with objects made of regolith simulant, demonstrating a high level of print precision and widening the range of uses such items could be put to,” comments ESA materials engineer Advenit Makaya. “If one needs to print tools or machinery parts to replace broken parts on a lunar base, precision in the dimensions and shape of the printed items will be vital.
“They are the work of innovative Austrian company Lithoz, working on 3D printed ceramics.
“Normally their print process is based on materials such as aluminium oxide, zirconium oxide or silicon nitride. What we’ve demonstrated here is that it can also work with raw regolith, which is a collection of various different types of oxides, chiefly silicon oxide but also aluminium, calcium and iron oxides, among others.”
Ground and sieved down to particle size, the regolith grains are mixed with a light-reacting binding agent, laid down layer-by-layer then hardened by exposing them to light. The resulting printed part is then ‘sintered’ in an oven to bake it solid.
Johannes Homa, CEO of Lithoz added: “Thanks to our expertise in the additive manufacturing of ceramics, we were able to achieve these results very quickly. We believe there’s a huge potential in ceramic additive manufacturing for the Moon.”
As a next step, the parts will be tested to check their strength and mechanical properties, with the idea that similar parts could one day be employed to replace parts in a lunar base without requiring replacements from Earth.
This work was carried out as part of the URBAN project, supported through ESA’s Discovery and Preparation Programme.
Credits: ESA–G. Porter, CC BY-SA 3.0 IGO
NGC 4618 was discovered on 9 April 1787 by the German-British astronomer, Wilhelm Herschel, who also discovered Uranus in 1781. Only a year before discovering NGC 4618, Herschel theorised that the “foggy” objects astronomers were seeing in the night sky were likely to be large star clusters located much further away then the individual stars he could easily discern.
Since Herschel proposed his theory, astronomers have come to understand that what he was seeing was a galaxy. NGC 4618, classified as a barred spiral galaxy, has the special distinction amongst other spiral galaxies of only having one arm rotating around the centre of the galaxy.
Located about 21 million light-years from our galaxy in the constellation Canes Venatici, NGC 4618 has a diameter of about one third that of the Milky Way. Together with its neighbour, NGC 4625, it forms an interacting galaxy pair, which means that the two galaxies are close enough to influence each other gravitationally. These interactions may result in the two (or more) galaxies merging together to form a new formation, such as a ring galaxy.
Credits: ESA/Hubble & NASA, I. Karachentsev; CC BY 4.0
ESA’s latest interplanetary mission, Juice, lifted off on an Ariane 5 rocket from Europe’s Spaceport in French 09:14 local time/14:14CEST on 14 April 2023 to begin its eight-year journey to Jupiter, where it will study in detail the gas giant planet’s three large ocean-bearing moons: Ganymede, Callisto and Europa.
Juice – Jupiter Icy Moons Explorer – is humankind’s next bold mission to the outer Solar System. This ambitious mission will characterise Ganymede, Callisto and Europa with a powerful suite of remote sensing, geophysical and in situ instruments to discover more about these compelling destinations as potential habitats for past or present life. Juice will monitor Jupiter’s complex magnetic, radiation and plasma environment in depth and its interplay with the moons, studying the Jupiter system as an archetype for gas giant systems across the Universe.
Following launch, Juice will embark on an eight-year journey to Jupiter, arriving in July 2031 with the aid of momentum and direction gained from four gravity-assist fly-bys of the Earth-Moon system, Venus and, twice, Earth.
Flight VA260 is the final Ariane 5 flight to carry an ESA mission to space.
Find out more about Juice in ESA’s launch kit
Credits: ESA - S. Corvaja
European Commissioner for Internal Market Thierry Breton coming face to the face with the atomic clocks at the heart of Europe’s Galileo satellite navigation system.
On Tuesday 7 September ESA Director General Josef Aschbacher took Commissioner Breton on a tour of ESA’s European Space Technology and Research Centre, ESTEC, at Noordwijk in the Netherlands.
Seen from left to right: Internal Market Cabinet Member Fabrice Comptour; ESA Director General Josef Aschbacher; Commissioner Breton and Andrea Contellessa, heading ESA’s Galileo Space Segment Management Office.
They looked in at ESTEC’s Navigation Laboratory, which includes the complete navigation module of a Galileo satellite, kept in cleanroom conditions for technical experiments and trouble shooting.
On the left side sits Galileo’s passive hydrogen maser atomic clock, sufficiently accurate that it would lose only one second over three million years. To the right is a rubidium atomic clock, which would only lose three seconds in one million years. Each satellite carries two each of these two clock types for maximum redundancy.
Commissioner Breton also inspected the six Galileo ‘Batch 3’ satellites currently being tested for space at ESTEC’s Test Centre, the largest satellite test facility in Europe. Two of these Galileo satellites are due for launch later this year.
About Galileo
The Galileo system is operated by the EU Agency for the Space Programme, EUSPA, based in Prague. ESA and EUSPA are partnering on respectively the development and operations of Galileo.
ESA is in charge of the design, development, procurement and qualification of Galileo satellites and their associated ground infrastructure on behalf of the European Union, the system’s owner.
Credits: ESA-G. Porter
This image of the young volcanic region of Elysium Planitia on Mars [10.3°N, 159.5°E] was taken on 14 April 2021 by the CaSSIS camera on the ESA-Roscosmos ExoMars Trace Gas Orbiter (TGO).
The two blue parallel trenches in this image, called Cerberus Fossae, were thought to have formed by tectonic processes. They run for almost one thousand km over the volcanic region. In this image, CaSSIS is looking straight down into one of these 2 km-wide fissures.
The floor here is a few hundred metres deep and is filled with coarse-grained sand, likely basaltic in composition, which appears blue in the CaSSIS false-colour composite image. The flat volcanic plains nearby are punctured by small impact craters, which expose possibly the same basaltic materials that we see within Cerberus Fossae.
TGO arrived at Mars in 2016 and began its full science mission in 2018. The spacecraft is not only returning spectacular images, but also providing the best ever inventory of the planet’s atmospheric gases, and mapping the planet’s surface for water-rich locations. It will also provide data relay services for the second ExoMars mission comprising the Rosalind Franklin rover and Kazachok platform, when it arrives on Mars in 2023.
Credits: ESA/Roscosmos/CaSSIS; CC BY-SA 3.0 IGO
At first glance, Saturn’s rings appear to be intersecting themselves in an impossible way. In actuality, this view from the international Cassini spacecraft shows the rings in front of the planet, upon which the shadow of the rings is cast. And because rings like the A ring and Cassini Division, which appear in the foreground, are not entirely opaque, the outline of Saturn and those ring shadows can be seen directly through the rings themselves.
Saturn’s rings have complex and detailed structures, many of which can be seen here. In some cases, the reasons for the gaps and ringlets are known: for example, 28 km wide moon Pan – seen here as a bright speck near the image centre – keeps open the Encke gap. But in other cases, the origins and natures of gaps and ringlets are less well understood.
This view looks toward the sunlit side of the rings from about 14º above the ring plane. The image was taken in visible light with Cassini’s narrow-angle camera on 11 February 2016, and highlighted in a release published 25 April 2016. The view was acquired at a distance of 1.9 million km from Pan and at a Sun–Pan–spacecraft angle of 85º. Image scale is 10 km/pixel.
The Cassini mission is a cooperative project of NASA, ESA and Italy’s ASI space agency. The mission concluded in September 2017.
Credits: NASA/JPL-Caltech/Space Science Institute
Space Science image of the week:
Perhaps you live in a part of the world where you regularly experience snow storms or even dust storms. But for many of us, the weather forms a natural part of everyday conversation – more so when it is somewhat extreme, like a sudden blizzard that renders transport useless or makes you feel highly disoriented as you struggle to fix your sights on recognisable landmarks.
ESA’s Rosetta mission had a similar experience, for more than two years, as it flew alongside Comet 67P/Churyumov–Gerasimenko between 2014 and 2016. It endured the endless impacts of dust grains launched by gaseous outpourings as the comet’s surface ices were warmed by the heat of the Sun, evaporating into space and dragging the dust along.
This image was taken two years ago, on 21 January 2016, when Rosetta was flying 79 km from the comet. At this time Rosetta was moving closer following perihelion in the previous August, when the comet was nearer to the Sun and as such at its most active, meaning that Rosetta had to operate from a greater distance for safety.
As can be seen from the image, the comet environment was still extremely chaotic with dust even five months later. The streaks reveal the dust grains as they passed in front of Rosetta’s camera, captured in the 146 second exposure.
Excessive dust in Rosetta’s field of view presented a continual risk for navigation: the craft’s startrackers used a star pattern recognition function to know its orientation with respect to the Sun and Earth. On some occasions flying much closer to the comet, and therefore through denser regions of outflowing gas and dust, the startrackers locked on to dust grains instead of stars, creating pointing errors and in some cases putting the spacecraft in a temporary safe mode.
Despite its dangers, the dust was of high scientific interest: three of Rosetta’s instruments studied tens of thousands of grains between them, collectively analysing their composition, their mass, momentum and velocity, and profiling their 3D structure. Studying the smallest and the most pristine grains ejected is helping scientists to understand the building blocks of comets.
Two years before the image was taken, 20 January 2014, Rosetta was only just waking up from 31 months of deep-space hibernation. It arrived at its destination after 10 years in space in August 2014, and released the lander Philae three months later. Rosetta made unique scientific observations of the comet until reaching its grand finale on 30 September 2016 by descending to the comet’s surface. By the end of the mission, more than a hundred thousand images had been taken by the high-resolution OSIRIS camera (including the one shown here) and the navigation camera, the majority of which are available to browse in the Archive Image Browser.
Credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA
With temperatures soaring and no rain to speak of, Europe is the grip of a heatwave. As well as the havoc that wildfires have caused in countries such as the UK, Sweden and Greece, the current heat is scorching our land and vegetation. These two images from the Copernicus Sentinel-2 mission show agricultural fields around the town of Slagelse in Zealand, Denmark. The image from July 2017 shows lush green fields, but as the image from this July shows, the heat and lack of rain has taken its toll on the health of the vegetation. This year’s summer weather means that the same comparison could be made for many other parts of Europe.
The two Copernicus Sentinel-2 satellites carry high-resolution multispectral optical imagers to monitor changes in vegetation. While the difference in plant health in these two images is clear to see, the mission offers measurements of leaf area index, leaf chlorophyll and leaf water content, which allow for a detailed assessment of plant health.
Credits: contains modified Copernicus Sentinel data (2017–18), processed by ESA, CC BY-SA 3.0 IGO
The European Robotic Arm (ERA) successfully made its first moves in orbit during the 250 spacewalk to upgrade the International Space Station.
Two spacewalkers worked outside the orbiting lab for 7 hours and 42 minutes on 28 April 2022. Russian cosmonauts Oleg Artemyev and Denis Matveev removed thermal blankets and then unlocked the robotic arm.
The duo released the launch locks that held the arm in its folded configuration for the journey to space last year. Inside the Space Station, crewmate Sergey Korsakov monitored the first commanded movements of the robotic arm.
One of the robotic arm’s end effectors moved for the first time shortly after 20:00 CEST (18:00 GMT). The European Robotic Arm translated to another base point in a “walkoff” manoeuvre.
The robotic arm brings new ways of operating automated machines to the orbital complex. ERA has the ability to perform many tasks automatically or semi-automatically, can be directed either from inside or outside the Station, and it can be controlled in real time or preprogrammed.
The International Space Station already has two robotic arms – Canadian and Japanese robots play a crucial role in berthing spacecraft and transferring payloads and astronauts.
ERA is the first robot capable of ‘walking’ around the Russian parts of the orbital complex. It can handle components up to 8000 kg with 5 mm precision, and it will transport astronauts from one working site to another.
Additional spacewalks are planned to continue outfitting the European Robotic Arm.
More information about the European Robotic Arm
Credits: ESA/NASA-M. Maurer CC BY-NC-SA 2.0
In this false-colour image, the CaSSIS camera on the ESA-Roscosmos ExoMars Trace Gas Orbiter captures the sides of the wall of an unnamed crater with a diameter of about 8 km. This crater is located in Mawrth Vallis, and its walls expose the rock record of this region. Mawrth is known to be rich in phyllosilicate clay minerals, which can only form under the presence of liquid water. Because of the presence and variety of these hydrated minerals, Mawrth Vallis is one of the most colourful areas on Mars.
The image was made by combining CaSSIS' blue, red and panchromatic filters.
Credits: ESA/Roscosmos/CaSSIS, CC BY-SA 3.0 IGO
The world’s most powerful space science telescope has opened its primary mirror for the last time on Earth.
As part of the international James Webb Space Telescope’s final tests, the 6.5 meter (21 feet 4 inch) mirror was commanded to fully expand and lock itself into place, just like it would in space. The conclusion of this test represents the team’s final checkpoint in a long series of tests designed to ensure Webb’s 18 hexagonal mirrors are prepared for a long journey in space, and a life of profound discovery. After this, all of Webb’s many movable parts will have confirmed in testing that they can perform their intended operations after being exposed to the expected launch environment.
Making the testing conditions close to what Webb will experience in space helps to ensure the observatory is fully prepared for its science mission one million miles away from Earth.
Commands to unlatch and deploy the side panels of the mirror were relayed from Webb’s testing control room at Northrop Grumman, in Redondo Beach, California. The software instructions sent, and the mechanisms that operated are the same as those used in space. Special gravity offsetting equipment was attached to Webb to simulate the zero-gravity environment in which its complex mechanisms will operate. All of the final thermal blanketing and innovative shielding designed to protect its mirrors and instruments from interference were in place during testing.
Webb is an international partnership between NASA, ESA and CSA. The telescope will launch on an Ariane 5 from Europe's Spaceport in French Guiana.
Credits: NASA/Chris Gunn
Measuring 4.5 metres across, this relatively small antenna in Australia, dubbed NNO-2, will be the first to hear from the soon-to-be-launched Aeolus satellite, the first ever to measure winds on Earth from Space.
Set for liftoff on 21 August 2018, at 22:20 GMT (23:20 CEST), Europe’s wind satellite will be lifted into space on a Vega rocket. Once the pair have reached the required orbital altitude, at about 320 km, the satellite will separate from its carrier, marking the beginning of its free flight journey around our planet.
Aeolus’ first steps after separation will include the automatic unfolding of its solar ‘wings’ and turning its antenna to face Earth to start sending signals. Only then will teams on the ground be able to get any sign from the satellite that all is well.
Until this point, for the first nervous moments after launch — about one hour and ten minutes — mission teams will be patiently waiting for the first message to be captured and transmitted by this small antenna at New Norcia, Australia.
Since 2015, NNO-2 has been pointing to space, listening for signals from rockets and newly launched satellites and transmitting instructions and commands to them from engineers on Earth.
This small and agile dish quickly and precisely locks onto and tracks satellites during their critical first orbits. As part of Estrack, ESA’s global system of ground stations, it provides vital links between satellites in orbit and the flight control teams at ESA’s mission control centre in Darmstadt, Germany.
You can watch the Aeolus launch live here, and follow @esaoperations for updates on the crucial period that follows, as mission teams regain control of the satellite, finally hearing its ‘first words’.
Credits: ESA
The ExoMars mission will see Rosalind Franklin the rover land on the Red Planet in 2023. Rosalind the rover has six wheels and a unique way of moving across the Red Planet. Each wheel pair is suspended on a pivoted bogie so each wheel can be steered and driven independently.
The replica ExoMars rover – the Ground Test Model (GTM) – that will be used in the Rover Operations Control Centre to support mission training and operations is completing several driving tests around the Mars Terrain Simulator.
This image shows the GTM driving through rough terrain.
Credits: Thales Alenia Space
This Picture of the Week, taken by the NASA/ESA Hubble Space Telescope, shows the galaxy NGC 4237. Located about 60 million light-years from Earth in the constellation of Coma Berenices (Berenice's Hair), NGC 4237 is classified as a flocculent spiral galaxy. This means that its spiral arms are not clearly distinguishable from each other, as in grand design spiral galaxies, but are instead patchy and discontinuous. This gives the galaxy a fluffy appearance, somewhat resembling cotton wool.
Astronomers studying NGC 4237 were actually more interested in its galactic bulge — its bright central region. By learning more about these bulges, we can explore how spiral galaxies have evolved, and study the growth of the supermassive black holes that lurk at the centres of most spirals. There are indications that the mass of the black hole at the centre of a galaxy is related to the mass of its bulge.
However, this connection is still uncertain, and why these two components should be so strongly correlated is still a mystery — one that astronomers hope to solve by studying galaxies in the nearby Universe, such as NGC 4237.
Credits: ESA/Hubble & NASA, P. Erwin et al.; CC BY 4.0
The galaxy pictured in this Hubble Picture of the Week has an especially evocative name: the Medusa merger.
Often referred to by its somewhat drier New General Catalogue designation of NGC 4194, this was not always one entity, but two. An early galaxy consumed a smaller gas-rich system, throwing out streams of stars and dust out into space. These streams, seen rising from the top of the merger galaxy, resembles the writhing snakes that Medusa, a monster in ancient Greek mythology, famously had on her head in place of hair, lending the object its intriguing name.
The legend of Medusa also held that anyone who saw her face would transform into stone. In this case, you can feast your eyes without fear on the centre of the merging galaxies, a region known as Medusa's eye. All the cool gas pooling here has triggered a burst of star formation, causing it to stand out brightly against the dark cosmic backdrop.
The Medusa merger is located about 130 million light-years away in the constellation of Ursa Major (The Great Bear).
Credits: ESA/Hubble & NASA, A. Adamo; CC BY 4.0
This dark, tangled web is an object named SNR 0454-67.2. It formed in a very violent fashion — it is a supernova remnant, created after a massive star ended its life in a cataclysmic explosion and threw its constituent material out into surrounding space. This created the messy formation we see in this NASA/ESA Hubble Space Telescope image, with threads of red snaking amidst dark, turbulent clouds.
SNR 0454-67.2 is situated in the Large Magellanic Cloud, a dwarf spiral galaxy that lies close to the Milky Way. The remnant is likely the result of a Type Ia supernova explosion; this category of supernovae is formed from the death of a white dwarf star, which grows and grows by siphoning material from a stellar companion until it reaches a critical mass and then explodes.
As they always form via a specific mechanism — when the white dwarf hits a particular mass — these explosions always have a well-known luminosity, and are thus used as markers (standard candles) for scientists to obtain and measure distances throughout the Universe.
Credits: ESA/Hubble, NASA; CC BY 4.0
Ariane 5 VA 260 with Juice ready for launch on the ELA-3 launch pad at Europe's Spaceport in Kourou, French Guiana on 12 April 2023.
Juice – JUpiter ICy moons Explorer – is humankind’s next bold mission to the outer Solar System. This ambitious mission will characterise Ganymede, Callisto and Europa with a powerful suite of remote sensing, geophysical and in situ instruments to discover more about these compelling destinations as potential habitats for past or present life. Juice will monitor Jupiter’s complex magnetic, radiation and plasma environment in depth and its interplay with the moons, studying the Jupiter system as an archetype for gas giant systems across the Universe.
Following launch, Juice will embark on an eight-year journey to Jupiter, arriving in July 2031 with the aid of momentum and direction gained from four gravity-assist fly-bys of the Earth-Moon system, Venus and, twice, Earth.
Flight VA 260 will be the final Ariane 5 flight to carry an ESA mission to space.
Find out more about Juice in ESA’s launch kit
Credits: ESA - S. Corvaja
The Space Launch System (SLS) rocket with the Orion spacecraft aboard lifted off at 07:47 CEST from NASA’s Kennedy Space Center in Florida, USA on 16 November 2022.
The most powerful rocket ever built sent NASA’s Orion spacecraft and ESA’s European Service Module (ESM) to a journey beyond the Moon and back. No crew will be on board Orion this time, and the spacecraft will be controlled by teams on Earth.
ESM provides for all astronauts’ basic needs, such as water, oxygen, nitrogen, temperature control, power and propulsion.
Much like a train engine pulls passenger carriages and supplies power, the European Service Module will take the Orion capsule to its destination and back.
Credits: ESA - S. Corvaja
What stars are made of can tell us about their birthplace and their journey afterwards, and therefore about the history of the Milky Way. With today’s data release, Gaia is bringing us a chemical map of the galaxy.
This all-sky view shows a sample of the Milky Way stars in Gaia’s data release 3. The colour indicates the stellar metallicity. Redder stars are richer in metals.
With Gaia, we see that some stars in our galaxy are made of primordial material, while others like our Sun are made of matter enriched by previous generations of stars. Stars that are closer to the centre and plane of our galaxy are richer in metals than stars at larger distances.
Read more about Gaia's data release 3 here.
Credits: ESA/Gaia/DPAC; CC BY-SA 3.0 IGO
The Meteosat Third Generation Imager-1 (MTG-I1) first image – view of the Mediterranean. The higher resolution of the imaging instrument on MTG-I1 provides information that Meteosat Second Generation (MSG) satellites could not deliver. The information is crucial for understanding the weather and climate. Visible in this ‘zoomed-in’ view of the Mediterranean is turbidity in coastal waters and snow on the Alps, the Apennine Mountains and the Dinaric Alps, as well as more detail about the cloud structures in the image. Some of these features are not visible in the same view taken at almost the same time by the imager on the MSG satellite, or not visible with the same amount of detail. The image was taken by the Flexible Combined Imager on MTG-I1 at 11:50 UTC on 18 March 2023.
Credits: EUMETSAT/ESA
Gaia’s sky mapper image showing the James Webb Space Telescope. The reddish colour is artificial, chosen just for illustrative reasons. The frame shows a few relatively bright stars, several faint stars, a few disturbances – and a spacecraft. It is marked by the green arrow.
Credits: ESA/Gaia/DPAC; CC BY-SA 3.0 IGO
The European Robotic Arm (ERA) successfully made its first moves in orbit during the 250 spacewalk to upgrade the International Space Station.
Two spacewalkers worked outside the orbiting lab for 7 hours and 42 minutes on 28 April 2022. Russian cosmonauts Oleg Artemyev and Denis Matveev removed thermal blankets and then unlocked the robotic arm.
The duo released the launch locks that held the arm in its folded configuration for the journey to space last year. Inside the Space Station, crewmate Sergey Korsakov monitored the first commanded movements of the robotic arm.
One of the robotic arm’s end effectors moved for the first time shortly after 20:00 CEST (18:00 GMT). The European Robotic Arm translated to another base point in a “walkoff” manoeuvre.
The robotic arm brings new ways of operating automated machines to the orbital complex. ERA has the ability to perform many tasks automatically or semi-automatically, can be directed either from inside or outside the Station, and it can be controlled in real time or preprogrammed.
The International Space Station already has two robotic arms – Canadian and Japanese robots play a crucial role in berthing spacecraft and transferring payloads and astronauts.
ERA is the first robot capable of ‘walking’ around the Russian parts of the orbital complex. It can handle components up to 8000 kg with 5 mm precision, and it will transport astronauts from one working site to another.
Additional spacewalks are planned to continue outfitting the European Robotic Arm.
More information about the European Robotic Arm
Credits: ESA/NASA-M. Maurer CC BY-NC-SA 2.0
Last week marked five years since ESA’s Rosetta probe arrived at its target, a comet named 67P/Churyumov-Gerasimenko (or 67P/C-G). Tomorrow, 13 August, it will be four years since the comet, escorted by Rosetta, reached its perihelion – the closest point to the Sun along its orbit. This image, gathered by Rosetta a couple of months after perihelion, when the comet activity was still very intense, depicts the nucleus of the comet with an unusual companion: a chunk of orbiting debris (circled).
Comet 67P/C-G is a dusty object. As it neared its closest approach to the Sun in late July and August 2015, instruments on Rosetta recorded a huge amount of dust enshrouding the comet. This is tied to the comet’s proximity to our parent star, its heat causing the comet’s nucleus to release gases into space, lifting the dust along. Spectacular jets were also observed, blasting more dust away from the comet. This disturbed, ejected material forms the ‘coma’, the gaseous envelope encasing the comet’s nucleus, and can create a beautiful and distinctive tail.
A single image from Rosetta’s OSIRIS instrument can contain hundreds of dust particles and grains surrounding the 4 km-wide comet nucleus. Sometimes, even larger chunks of material left the surface of 67P/C-G – as shown here.
The sizeable chunk in this view was spotted a few months ago by astrophotographer Jacint Roger from Spain, who mined the Rosetta archive, processed some of the data, and posted the finished images on Twitter as an animated GIF. He spotted the orbiting object in a sequence of images taken by Rosetta’s OSIRIS narrow-angle camera on 21 October 2015. At that time, the spacecraft was at over 400 km away from 67P/C-G’s centre. The animated sequence is available for download here.
Scientists at ESA and in the OSIRIS instrument team are now looking into this large piece of cometary debris in greater detail. Dubbed a ‘Churymoon’ by researcher Julia Marín-Yaseli de la Parra, the chunk appears to span just under 4 m in diameter.
Modelling of the Rosetta images indicates that this object spent the first 12 hours after its ejection in an orbital path around 67P/C-G at a distance of between 2.4 and 3.9 km from the comet’s centre. Afterwards, the chunk crossed a portion of the coma, which appears very bright in the images, making it difficult to follow its path precisely; however, later observations on the opposite side of the coma confirm a detection consistent with the orbit of the chunk, providing an indication of its motion around the comet until 23 October 2015.
Scientists have been studying and tracking debris around 67P/C-G since Rosetta’s arrival in 2014. The object pictured in this view is likely the largest chunk detected around the comet, and will be subject to further investigations.
Comet 67P/C-G is currently in the outer Solar System, between the orbits of Mars and Jupiter, and will have its next perihelion in late 2021.
Credits: ESA/Rosetta/MPS/OSIRIS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA/J. Roger (CC BY 4.0)
ESA’s Hertz radio frequency test chamber will be playing a supporting role in a forthcoming production at the Dutch National Opera in Amsterdam.
The cavernous foam-lined space – located in ESA’s ESTEC technical centre in the Netherlands – was filmed by a team from filming company WE ARE WILL, along with a neighbouring clean room, to serve as a futuristic backdrop to the events on stage.
In next year’s Upload, a father and daughter travel to a very special clinic. The parent wants to give up his physical body and have his mind uploaded into a digital version of himself, to try and escape past trauma and achieve immortality. But why did he make this choice, and how will this change his relationship with his daughter?
“The show is a hybrid of styles, set well into the future,” explains Michel Van der Aa, composer and director of the opera.
“Hertz was one of the first places I thought of to suggest that setting, from a magazine photo in my ideas folder. The locations will be seen on stage largely as filmed, projected onto layers of screens like a box around the performers, to represent their physical surroundings.
‘Hertz is an amazing, very theatrical looking space – which doubles in our production as the clinic’s scanning chamber. Then, for our climax, final stage of the uploading takes place in the other chamber we scanned at ESTEC, a clean room for satellite storage inside the Test Centre.”
Upload receives its premiere in Amsterdam on 17 March 2021, with tickets on sale soon, before going on tour to Germany, Austria and the US.
Credits: ESA-SJM Photography
Infographic showing the systems used to communicate with the International Space Station and how data is relayed to ESA's Columbus Control Centre in Oberpfaffenhofen, Germany.
Aside from using the Russian and NASA communication systems. astronauts on board the International Space Station are now connecting straight to Europe at light speed, thanks to the European Data Relay System. The satellite picks up signals from the Station as it loops around the Earth every 90 minutes and relays them straight back to its European base station.
The state-of-the-art system provides speeds of up to 50 Mbit/s for downlink and up to 2 Mbit/s for uplink. The communications device which enables it – nicknamed ‘ColKa’ for ‘Columbus laboratory Ka-band terminal’ – was installed during a spacewalk in January 2021.
Credits: ESA–K. Oldenburg
The Rhine River, the longest river in Germany, is featured in this colourful image captured by the Copernicus Sentinel-2 mission. Along this river lies the city of Bonn: the host of this year’s Living Planet Symposium – one of the largest Earth observation conferences in the world – taking place on 23–27 May 2022.
The Rhine River, visible here in black, flows from the Swiss Alps to the North Sea through Switzerland, Liechtenstein, Austria, France, Germany, and the Netherlands. In the image, the Rhine flows from bottom-right to top-left. The river is an important waterway with an abundance of shipping traffic, with import and export goods from all over the world.
The picturesque Rhine Valley has many forested hills topped with castles and includes vineyards, quaint towns and villages along the route of the river. One particular stretch that extends from Bingen in the south to Koblenz, known as the Rhine Gorge, has been declared a UNESCO World Heritage Site (not visible).
Cologne is visible at the top of the image.
This composite image was created by combining three separate Normalised Difference Vegetation Index (NDVI) layers from the Copernicus Sentinel-2 mission. The Normalised Difference Vegetation Index is widely used in remote sensing as it gives scientists an accurate measure of health and status of plant growth.
Each colour in this week’s image represents the average NDVI value of an entire season between 2018 and 2021. Shades of red depict peak vegetation growth in April and May, green shows changes in June and July, while blue shows August and September.
Colourful squares, particularly visible in the left of the image, show different crop types. The nearby white areas are forested areas and appear white as they retain high NDVI values through most of the growing season, unlike crops which are planted and harvested at set time frames. Light pink areas are grasslands, while the dark areas (which have a low NDVI) are built-up areas and water bodies.
Along the Rhine River lies the World Conference Center Bonn. It is here where ESA’s Living Planet Symposium 2022 will take place.
Organised with the support of the German Aerospace Center, the Living Planet Symposium will bring together scientists and researchers, as well as industry and users of Earth observation data, from all over the world to present and discuss the latest findings on Earth science.
The week-long event focuses on how Earth observation contributes to science and society, and how disruptive technologies and actors are changing the traditional Earth observation landscape, which is also creating new opportunities for public and private sector interactions.
The Living Planet Symposium will be held in-person offering you the chance to network with the most eminent scientists in the industry, learn about novel Earth observing techniques and explore innovative concepts such as New Space, the digital transformation and commercialisation.
To attend the event in person, you just need to register by next Monday 9 May. More information can be found at the Living Planet Symposium website.
This image is also featured on the Earth from Space video programme.
Credits: Contains modified Copernicus Sentinel data (2018-21), processed by ESA, CC BY-SA 3.0 IGO
An elevation map of Jezero Crater on Mars, the landing site for NASA's 2020 Mars Perseverance rover. Lighter colours represent higher elevation.
Two recent studies based on ESA's Mars Express observations of Jezero crater have shed light on how and when this intriguing area formed – and identified the regions most likely to reveal signs of ancient life.
The crater rim stands out clearly in this colour map, making it easier to spot the shoreline of a lake that dried up billions of years ago. The oval indicates the landing ellipse, where the rover will be touching down on Mars. Scientists are interested in studying this shoreline because it may have preserved fossilised microbial life, if any ever formed on the Red Planet.
This image was created using data from a combination of instruments and spacecraft: NASA's Mars Global Surveyor and its Mars Orbiter Laser Altimeter (MOLA); NASA's Mars Reconnaissance Orbiter and its Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) and Context Camera (CTX); and the High Resolution Stereo Camera (HRSC) on ESA's Mars Express. It was originally published in November 2019.
Full story: Mars Express helps uncover the secrets of Perseverance landing site
Credits: NASA/JPL-Caltech/MSSS/JHU-APL/ESA
The Copernicus Sentinel-2 mission takes us over part of Sindh – the third-largest province of Pakistan.
Sindh stretches around 580 km from north to south in southern Pakistan, covering an area of around 141 000 sq km. It is bounded by the Thar Desert to the east, the Kirthar mountains to the west and the Arabian Sea to the south. In the centre of the province is a fertile plain around the Indus River.
Agricultural fields dominate this weeks’ Earth from Space image, creating a colourful patchwork of geometric shapes. Agriculture is key to Sindh’s economy with cotton, wheat, rice, sugarcane and maize being the major crops produced in the province. Livestock raising is also important, with cattle, buffalo, sheep and goats being the main animals kept.
The colourful image was created by combining three separate images from the near-infrared channel from the Copernicus Sentinel-2 mission.
The first image, captured on 15 October 2021, is assigned to the red channel; the second from 24 November 2021, represents green, and the third from 13 January 2022 covers the blue part of the spectrum. All other colours visible in the image are different mixtures of red, green and blue, and vary according to the stage of vegetation growth over the four-month period.
The city of Badin is visible in the centre-right of the image and is often referred to as ‘Sugar State’ owing to its production of sugar. Small lakes, artificial water bodies and some flooded fields can be spotted in dark blue and black in the image.
Thanks to their unique perspective from space, Earth observing satellites are key in mapping and monitoring croplands. The Copernicus Sentinel-2 mission is specifically designed to provide images that can be used to distinguish between crop types as well as data on numerous plant indices, such as leaf area index, leaf chlorophyll content and leaf water content – all of which are essential to accurately monitor plant growth.
The image is also featured on the Earth from Space video programme.
Credits: contains modified Copernicus Sentinel data (2021-22), processed by ESA, CC BY-SA 3.0 IGO
ESA’s Jupiter Icy Moons Explorer (Juice) being fuelled inside the payload preparation facility at Europe’s Spaceport in French Guiana ahead of its launch on an Ariane 5 on 13 April.
Juice will use this propellant to make critical course manoeuvres on its journey to and around the Jupiter system, and to go into orbit around Jupiter then its largest moon, Ganymede. Juice has a bi-propellant chemical propulsion system, using mono-methyl hydrazine (MMH) fuel and mixed oxides of nitrogen (MON) oxidiser. This results in a propellant that spontaneously ignites when the two come into contact with each other.
Fuelling any satellite is a particularly delicate operation requiring setup of the equipment and connections, fuelling, and then pressurisation. The propellants are extremely toxic so only a few specialists wearing protective Self-Contained Atmospheric Protective Ensemble, or ‘scape’ suits, remained in the dedicated hall for fuelling.
Juice is humankind’s next bold mission to the outer Solar System. It will make detailed observations of gas giant Jupiter and its three large ocean-bearing moons: Ganymede, Callisto and Europa. This ambitious mission will characterise these moons with a powerful suite of remote sensing, geophysical and in situ instruments to discover more about these compelling destinations as potential habitats for past or present life. Juice will monitor Jupiter’s complex magnetic, radiation and plasma environment in depth and its interplay with the moons, studying the Jupiter system as an archetype for gas giant systems across the Universe.
Find out more about Juice in ESA’s launch kit
Credits: 2023 ESA-CNES-ARIANESPACE / Optique vidéo du CSG - JM GUILLON
On 6 August of 2014, after a decade of travelling through interplanetary space, ESA’s Rosetta spacecraft arrived at its final target: Comet 67P/Churyumov-Gerasimenko (67P/C-G). The mission was the first to successfully land on a comet when it sent the lander Philae down to the surface a few months later, while the orbiter studied 67P/C-G in detail before the mission’s end on 30 September 2016.
Over its lifetime Rosetta extensively mapped the comet’s surface, which has since been divided into 26 geological regions named after Ancient Egyptian deities. The entire comet has been likened to a duck in shape, with a small ‘head’ attached to a larger ‘body’.
This image shows a section of 67P/C-G as viewed by Rosetta’s high-resolution camera OSIRIS on 10 February 2016. Amateur astronomer Stuart Atkinson, from the UK, selected and processed this view from the OSIRIS image archive. It is a crop of a larger image that shows a slightly wider view of the comet’s ‘Bes’ region on body of the comet, which takes its name from the protective deity of households, children and mothers.
It shows the uneven, shadowed surface of the comet in detail; particularly prominent just to the right of centre is an upright feature surrounded by scattered depressions, rocky outcrops and debris.
Explore the full mission image archive yourself here and let us know what hidden treasures you find via @esascience.
Credits: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA – CC BY 4.0; Acknowledgement: S Atkinson.
This beautiful dune field lies inside a crater near the south polar region of Mars.
The image was taken by the ExoMars Trace Gas Orbiter’s Colour and Stereo Surface Imaging System, CaSSIS, on 18 May 2018, at the beginning of martian southern spring, when a thin layer of seasonal carbon dioxide ice was still covering the surface. Over the winter, the ice grains in this thin layer appear to grow enough that the ice becomes almost transparent, letting light through and heating up the surface from the bottom of the ice. As the ice begins to sublimate from the bottom up, pressure builds up, and it is released through instabilities and cracks in the ice layer, in what scientists think are geyser-like processes of carbon dioxide gas that push out martian sand. The black streaks seen all across this image are examples of the darker sand being propelled out through the ice cracks and down the slip face of the dunes.
The ExoMars programme is a joint endeavour between ESA and Roscosmos.
More about ExoMars
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Credits: ESA/Roscosmos/CaSSIS, CC BY-SA 3.0 IGO
Space Science Image of the week:
Of all the icy moons in the Solar System, Saturn’s moon Enceladus is probably the ‘hottest’ when measured for its potential to host life. Despite its distance from Earth, it may also be the easiest to investigate.
Buried beneath its icy crust is a global ocean of water , much like the one scientists are convinced lies inside Jupiter’s moon Europa. The question is how to get below what is probably tens of kilometres of ice to see if there is life in the water.
Although this is the problem at Europa, at Enceladus the moon does some of the work for you. At its south poles, huge geysers of water jet into space. These come from the ocean depths and suggest that the ice there must be relatively thin for this to happen. But how thin? Planetary scientists may now have an answer.
The international Cassini spacecraft has been paying particular attention to Enceladus since arriving at Saturn in 2004. Indeed, it was Cassini that discovered the geysers on Enceladus in the first place. Now there are more than 100 individual jets known on the moon, each spewing water into space.
A team of independent researchers have now taken all of the data about Enceladus collected by the spacecraft and built a computer simulation of the moon that includes the thickness of the ice crust.
This picture of Enceladus has been created using data taken by Cassini’s high-resolution camera. The ice crust thickness, indicated by the colour, has then been plotted over the moon’s surface. According to the model, the thickness varies between about 35 km in the cratered equatorial regions (yellow) to less than 5 km in the active south polar terrain (blue).
In astronomical terms, this is paper-thin. The model predicts that the 505 km-wide moon contains a core that is 360–370 km in diameter. The rest is ocean and the ice crust, with the ice crust itself having an average thickness of 18–22 km.
Remarkably, however, the model predicts that the thickness of the ice reduces to less than 5 km at the south pole. This could make it easier for the water to escape along cracks and fissures.
Last year Cassini flew through the geysers, analysing the water with its instruments. On previous occasions, the discovery of silica particles, likely originating from Enceladus, and the presence of methane in the water plumes indicated there is hydrothermal activity at the ocean’s floor. This water and the chemicals were then transported from the floor to the base of the ice crust, and subsequently jetted through and out into space.
No one knows how the geysers are powered but showing that the ice crust could be much thinner than previously thought is intriguing.
Credit: LPG-CNRS-U. Nantes/Charles U., Prague
ESA’s Young Professionals Satellite, YPSat, seen undergoing its initial thermal vacuum test in ESA’s Mechanical Systems Laboratory.
Sustained exposure to high-quality vacuum and temperature extremes mimic the conditions YPSat will experience in Earth orbit
YPSat is a project run in its entirety by ESA Young Professionals to give them direct early experience of designing, building and testing for space. Its goal is to capture all the key phases of Ariane 6's inaugural flight.
This ‘thermal vacuum’ testing was used to check the accuracy of the mathematical model of the payload’s thermal performance and verify its thermal control design – including the shiny multi-layer insulation it is wrapped in. The data from this initial test campaign will guide a follow-up thermal vacuum campaign planned for April.
Credits: ESA
The hot firing of the development model of the P120C solid fuel rocket motor at Europe’s Spaceport in French Guiana on 16 July 2018, proves the design for use on Vega-C next year and on Ariane 6 from 2020.
The P120C is 13.5 m long and 3.4 m in diameter, and uses solid fuel in a case made of carbon composite material built in a single segment.
It will replace the current P80 as the first stage motor of Vega-C. Two or four P120Cs will be strapped onto Ariane 6 as boosters for liftoff.
This test was a collaboration between ESA, France’s CNES space agency, and Europropulsion under contract to Avio and ArianeGroup.
Credits: ESA/CNES
Deadly wildfires continue to rage in south-central Chile destroying hundreds of thousands of hectares of land across the country. Satellite images captured by the Copernicus Sentinel-3 mission on 4 February show the ongoing fires and heatwave in South America.
The fires in Chile have consumed approximately 270 000 hectares of land, killing over 20 and injuring more than 1000 people. The government has declared a state of emergency in the Biobío, Ñuble and Araucania regions and is seeking international assistance to battle the fires from neighbouring countries.
The optical image is a combination of images from the Ocean and Land Colour Instrument (OCLI) and Sea and Land Surface Temperature Radiometer (SLSTR) onboard the Sentinel-3 satellite. This allows us to highlight the fire hotspots visible in shades of orange and red in the image.
Chile is suffering through a decade-long period of dry weather. The searing heatwave and strong winds have caused the flames to spread and has complicated efforts to extinguish the flames, with air temperatures exceeding 40°C in some of the most affected areas. According to the Global Drought Observatory report, the current drought event in the Parana-La Plata Basin is the worst since 1944.
The blazes impact air quality as they release large quantities of aerosol into the atmosphere. The Copernicus Atmosphere Service reported forecasts of particulate matter 2.5 levels in the atmosphere up until 8 February.
In response to the wildfires, the Copernicus Emergency Mapping Service has been activated. Chile had requested support from the Member and Participating States to help limit the consequences of the destructive fires. The service uses observations from multiple satellites to provide on-demand mapping to help civil protection authorities and the international humanitarian community in the face of major emergencies.
Credits: contains modified Copernicus Sentinel data (2023), processed by ESA, CC BY-SA 3.0 IGO
This image of the Argyre impact basin in the southern highlands of Mars was taken on 28 April 2020 just as Mars had passed its southern hemisphere spring equinox. The seasonal ice in the 800km-long impact basin is receding while the ridge on the right side of the image is still covered with frost. The image is centred at 57.5°S, 310.2°E. The frost-covered ridge is facing the pole, therefore receiving less solar radiation than the neighbouring equator-facing slope. On Mars, incoming solar radiation transforms the ice into water vapour directly without melting it first into water in a process called sublimation. Since the north-facing slope (on the left) has had a longer exposure to solar radiation, its ice has sublimated more quickly.
Credits: ESA/ExoMars/CaSSIS
Ahead of Galileo satellites like this one going to space, they are switched on as if already operating there within ESA’s Maxwell EMC Facility. This test procedure is a check of the satellite’s ‘electromagnetic compatibility’, with all its systems running together to detect any harmful interference between them.
Once Maxwell's main door is sealed, its metal walls form a ‘Faraday Cage’, screening out external electromagnetic signals. The ‘anechoic’ foam pyramids covering its interior absorb internal signals – as well as sound – to prevent any reflection, mimicking the infinite void of space for satellite testing.
Seen here sheathed in multi-layer insulation, the 2.5m by 1.2 m by 1.1 m satellite’s main 1.4-m diameter antenna transmits L-band navigation signals down to Earth. To its left is the hexagonal search and rescue antenna that picks up distress signals and relays them to local emergency services, contributing to the saving of more than 2000 lives annually.
To the bottom right of the navigation antenna are a pair of infrared ‘Earth sensors’ whose task is to keep the navigation permanently locked onto Earth by homing in on the contrast between the heat of Earth’s atmosphere and the cold of deep space. Above them is the laser retro-reflector: lasers are shone up to this from the stations of the International Laser Ranging Service to perform an independent check of the satellite’s orbital position down to an accuracy of less than a centimetre, as a backup of standard radio ranging.
Above that is the circular C-band antenna which every 45 minutes or so receives the navigation messages from the Galileo ground segment. These signals incorporate corrections for slight clock errors, orbital drift or satellite malfunctions that user receivers can process as they perform positioning fixes, helping ensure Galileo remains the world’s most accurate satellite navigation system, delivering metre-scale positioning to users around the globe.
What resembles a white baton on the end of the satellite is its S-band antenna, employed to return ‘housekeeping’ telemetry data to mission control on Earth and pick up telecommands in turn to operate the satellite platform and payload – as well as performing the ranging used to estimate the satellite’s position in space.
The Maxwell EMC Facility is part of the ESTEC Test Centre in ESA’s technical heart in Noordwijk, the Netherlands – Europe’s largest satellite testing facility, which has flight-tested all but two of the 28 Galileo satellites already in orbit, and is currently doing the same for the next 10 satellites planned to join the constellation.
About Galileo
Galileo is currently the world’s most precise satellite navigation system, serving more than three billion users around the globe.
The Full Operational Capability phase of the Galileo programme is managed and funded by the European Union. The European Commission, ESA and EUSPA (the EU Agency for the Space Programme) have signed an agreement by which ESA acts as design authority and system development prime on behalf of the Commission and EUSPA as the exploitation and operation manager of Galileo/EGNOS. “Galileo” is registered as a trademark in the database of the European Union Intellectual Property Office (n° 002742237).
Credits: ESA-P. Muller
This image, based on observations from NASA’s Dawn spacecraft, shows the largest mountain on the dwarf planet Ceres.
Dawn was the first mission to orbit an object in the asteroid belt between Mars and Jupiter, and spent time at both large asteroid Vesta and dwarf planet Ceres. Ceres is one of just five recognised dwarf planets in the Solar System (Pluto being another). Dawn entered orbit around this rocky world on 6 March 2015, and studied its icy, cratered, uneven surface until it ran out of fuel in October of 2018.
One of the features spotted by the mission is shown here in this reconstructed perspective view: a mountain named Ahuna Mons. This mountain rises to an elevation of 4000 m at its peak – Europe’s Mont Blanc on Earth would rise slightly above it (as measured from sea level) – and is marked by numerous bright streaks that run down its flanks. Scientists have determined that these marks are actually salt deposits left behind from the formation of Ahuna Mons, when plumes of saltwater and mud rose and erupted from within Ceres, puncturing the surface and creating the mountain seen here. While temperatures on Ceres are far colder than those on Earth, this mechanism is thought to be somewhat similar to the formation of volcanoes by terrestrial magma plumes.
More recently, a study of Dawn data led by ESA research fellow Ottaviano Ruesch and Antonio Genova (Sapienza Università di Roma), published in Nature Geoscience in June, suggests that a briny, muddy ‘slurry’ exists below Ceres’ surface, surging upwards towards and through the crust to create Ahuna Mons. Another recent study, led by Javier Ruiz of Universidad Complutense de Madrid and published in Nature Astronomy in July, also indicates that the dwarf planet has a surprisingly dynamic geology.
Ceres was also the focus of an earlier study by ESA’s Herschel space observatory, which detected water vapour around the dwarf planet. Published in Nature in 2014, the result provided a strong indication that Ceres has ice on or near its surface. Dawn confirmed Ceres’ icy crust via direct observation in 2016, however, the contribution of the ice deposits to Ceres’ exosphere turned out to be much lower than that inferred from the Herschel observations.
The perspective view depicted in this image uses enhanced-colour combined images taken using blue (440 nm), green (750 nm), and infrared (960 nm) filters, with a resolution of 35 m/pixel. Ahuna Mons’ elevation has been exaggerated by a factor of two. The width of the dome is approximately 20 km. The spacecraft’s Framing Camera took the images from Dawn’s low-altitude mapping orbit from an altitude of 385 km in August 2016.
Credits: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA
Stellar nurseries are cloudy and dusty places that shine brightly in infrared light. The G305 star-forming complex is no exception. It features a number of bright, intricate gas clouds heated by infant stars in their midst. In this spectacular image by ESA’s Herschel space observatory, these star-forming hotspots stand out in a blue tone that contrasts with the red-brownish colour of cooler regions.
While there are several star-formation sites dotted throughout this scene, the most striking ones surround the dark, heart-shaped area in the top right of the image. Hidden at the centre of the dark region lie the massive star WR48a and its two neighbours, stellar clusters Danks 1 and 2. All three play an important role in triggering the formation of new stars, even if they themselves are relatively young objects no older than a few million years (for comparison, the Sun is around 4.6 billion years old).
Strong winds and radiation from WR48a and the high-mass stars in the two clusters have pushed away the gas remnants from the cloud where they originated. The swept-away gas, gathered together at the edge of the heart-shaped bubble, is now forming new stars.
Using Herschel, astronomers have identified 16 sites where high-mass stars are forming in this stellar nursery. The region is one of the brightest and most plentiful star-forming complexes in the Milky Way, and an ideal ground to observe and study massive stars at different stages of formation and evolution.
The G305 complex is about 12 000 light-years away and gets its name from its location at around 305º longitude in the plane of our Galaxy. In the night sky, it appears near the Coalsack Nebula, a large interstellar cloud of dust visible to the naked eye and located in the constellation of Crux, the Southern Cross. A very prominent dark nebula, Coalsack shows up in the southern skies as a black patch against the bright, starry backdrop of the Milky Way.
This image, obtained as part of Hi-GAL – the Herschel infrared Galactic Plane Survey, combines observations at three different wavelengths: 70 microns (blue), 160 microns (green) and 250 microns (red).
Launched in 2009, Herschel operated for four years observing at far infrared and submillimetre wavelengths. This spectral range allowed it to observe the glow of dust in gas clouds where stars are born to investigate this process and observe their early evolution.
Credits: ESA/Herschel/PACS, SPIRE/Hi-GAL Project. Acknowledgement: UNIMAP / L. Piazzo, La Sapienza – Università di Roma; E. Schisano / G. Li Causi, IAPS/INAF, Italy
This Picture of the Week from the NASA/ESA Hubble Space Telescope shows NGC 5307, a planetary nebula which lies about 10000 light years from Earth. It can be seen in the constellation Centaurus (The Centaur), which can be seen primarily in the southern hemisphere. A planetary nebula is the final stage of a Sun-like star. As such, planetary nebulae allow us a glimpse into the future of our own Solar System. A star like our Sun will, at the end of its life, transform into a red giant. Stars are sustained by the nuclear fusion that occurs in their core, which creates energy. The nuclear fusion processes constantly try to rip the star apart. Only the gravity of the star prevents this from happening.
At the end of the red giant phase of a star, these forces become unbalanced. Without enough energy created by fusion, the core of the star collapses in on itself, while the surface layers are ejected outward. After that, all that remains of the star is what we see here: glowing outer layers surrounding a white dwarf star, the remnants of the red giant star’s core.
This isn’t the end of this star’s evolution though — those outer layers are still moving and cooling. In just a few thousand years they will have dissipated, and all that will be left to see is the dimly glowing white dwarf.
Credits: ESA/Hubble & NASA, R. Wade et al.; CC BY 4.0
Located in the constellation of Hercules, about 230 million light-years away, NGC 6052 is a pair of colliding galaxies. They were first discovered in 1784 by William Herschel and were originally classified as a single irregular galaxy because of their odd shape. However, we now know that NGC 6052 actually consists of two galaxies that are in the process of colliding. This particular image of NGC 6052 was taken using the Wide Field Camera 3 on the NASA/ESA Hubble Space Telescope.
A long time ago gravity drew the two galaxies together into the chaotic state we now observe. Stars from within both of the original galaxies now follow new trajectories caused by the new gravitational effects. However, actual collisions between stars themselves are very rare as stars are very small relative to the distances between them (most of a galaxy is empty space). Eventually things will settle down and one day the two galaxies will have fully merged to form a single, stable galaxy.
Our own galaxy, the Milky Way, will undergo a similar collision in the future with our nearest galactic neighbour, the Andromeda Galaxy. Although this is not expected to happen for around 4 billion years so there is nothing to worry about just yet.
This object was previously observed by Hubble with its old WFPC2 camera. That image was released in 2015.
Credits: ESA/Hubble & NASA, A. Adamo et al.; CC BY 4.0
With its powerful, mid-infrared vision, MIRI shows never-before-seen details of Stephan’s Quintet, a visual grouping of five galaxies. MIRI pierced through dust-enshrouded regions to reveal huge shock waves and tidal tails, gas and stars stripped from the outer regions of the galaxies by interactions. It also unveiled hidden areas of star formation. The new information from MIRI provides invaluable insights into how galactic interactions may have driven galaxy evolution in the early universe.
This image contains one more MIRI filter than was used in the NIRCam-MIRI composite picture. The image processing specialists at the Space Telescope Science Institute in Baltimore opted to use all three MIRI filters and the colours red, green and blue to most clearly differentiate the galaxy features from each other and the shock waves between the galaxies.
In this image, red denotes dusty, star-forming regions, as well as extremely distant, early galaxies and galaxies enshrouded in thick dust. Blue point sources show stars or star clusters without dust. Diffuse areas of blue indicate dust that has a significant amount of large hydrocarbon molecules. For small background galaxies scattered throughout the image, the green and yellow colours represent more distant, earlier galaxies that are rich in these hydrocarbons as well.
Stephan’s Quintet’s topmost galaxy – NGC 7319 – harbours a supermassive black hole 24 million times the mass of the Sun. It is actively accreting material and puts out light energy equivalent to 40 billion Suns. MIRI sees through the dust surrounding this black hole to unveil the strikingly bright active galactic nucleus.
As a bonus, the deep mid-infrared sensitivity of MIRI revealed a sea of previously unresolved background galaxies reminiscent of Hubble’s Deep Fields.
Together, the five galaxies of Stephan’s Quintet are also known as the Hickson Compact Group 92 (HCG 92). Although called a “quintet,” only four of the galaxies are truly close together and caught up in a cosmic dance. The fifth and leftmost galaxy, called NGC 7320, is well in the foreground compared with the other four. NGC 7320 resides 40 million light-years from Earth, while the other four galaxies (NGC 7317, NGC 7318A, NGC 7318B, and NGC 7319) are about 290 million light-years away. This is still fairly close in cosmic terms, compared with more distant galaxies billions of light-years away. Studying these relatively nearby galaxies helps scientists better understand structures seen in a much more distant universe.
This proximity provides astronomers a ringside seat for witnessing the merging of and interactions between galaxies that are so crucial to all of galaxy evolution. Rarely do scientists see in so much exquisite detail how interacting galaxies trigger star formation in each other, and how the gas in these galaxies is being disturbed. Stephan’s Quintet is a fantastic “laboratory” for studying these processes fundamental to all galaxies.
Tight groups like this may have been more common in the early universe when their superheated, infalling material may have fueled very energetic black holes called quasars. Even today, the topmost galaxy in the group – NGC 7319 – harbours an active galactic nucleus, a supermassive black hole that is actively pulling in material.
MIRI was contributed by ESA and NASA, with the instrument designed and built by a consortium of nationally funded European Institutes (The MIRI European Consortium) in partnership with JPL and the University of Arizona.
Get the full array of Webb’s first images and spectra, including downloadable files, here.
Credits: NASA, ESA, CSA, and STScI
The ESA-JAXA BepiColombo mission to Mercury lifts off from Europe’s Spaceport in Kourou.
Credits: ESA - S. Corvaja
This atmospheric Picture of the Week, taken with the NASA/ESA Hubble Space Telescope, shows a dark, gloomy scene in the constellation of Gemini (The Twins). The subject of this image confused astronomers when it was first studied — rather than being classified as a single object, it was instead recorded as two objects, owing to its symmetrical lobed structure (known as NGC 2371 and NGC 2372, though sometimes referred to together as NGC 2371/2).
These two lobes are visible to the upper left and lower right of the frame, and together form something known as a planetary nebula. Despite the name, such nebulae have nothing to do with planets; NGC 2371/2 formed when a Sun-like star reached the end of its life and blasted off its outer layers, shedding the constituent material and pushing it out into space to leave just a superheated stellar remnant behind. This remnant is visible as the orange-tinted star at the centre of the frame, sitting neatly between the two lobes.
The structure of this region is complex. It is filled with dense knots of gas, fast-moving jets that appear to be changing direction over time, and expanding clouds of material streaming outwards on diametrically opposite sides of the remnant star. Patches of this scene glow brightly as the remnant star emits energetic radiation that excites the gas within these regions, causing it to light up. This scene will continue to change over the next few thousand years; eventually the knotty lobes will dissipate completely, and the remnant star will cool and dim to form a white dwarf.
Credits: ESA/Hubble & NASA, R. Wade et al.; CC BY 4.0
Meet NGC 5728, a spiral galaxy around 130 million light-years from Earth. This image was captured using Hubble’s Wide Field Camera 3 (WFC3), which is extremely sensitive to visible and infrared light. Therefore, this image beautifully captures the regions of NGC 5728 that are emitting visible and infrared light. However, there are many other types of light that galaxies such as NGC 5728 can emit, which WFC3 cannot see.
In this image, NCG 5728 appears to be an elegant, luminous, barred spiral galaxy. What this image does not show, however, is that NGC 5728 is also a monumentally energetic type of galaxy, known as a Seyfert galaxy. This extremely energetic class of galaxies are powered by their active cores, which are known as active galactic nuclei (AGNs). There are many different types of AGNs, and only some of them power Seyfert galaxies. NGC 5728, like all Seyfert galaxies, is distinguished from other galaxies with AGNs because the galaxy itself can be seen clearly. Other types of AGNs, such as quasars, emit so much radiation that it is almost impossible to observe the galaxy that houses them. As this image shows, NGC 5728 is clearly observable, and at optical and infrared wavelengths it looks quite normal. It is fascinating to know that the galaxy’s centre is emitting vast amounts of light in parts of the electromagnetic spectrum that WFC3 just isn’t sensitive to! Just to complicate things, the AGN at NGC 5728’s core might actually be emitting some visible and infrared light — but it may be blocked by the dust surrounding the galaxy’s core.
Credits: ESA/Hubble, A. Riess et al., J. Greene; CC BY 4.0
The Copernicus Sentinel-2B satellite takes us over Alaska’s Columbia Glacier, one of the most rapidly changing glaciers in the world.
The glacier, which can be seen just below the middle of the image, flows down the snow-covered slopes of the Chugach Mountains into the Prince William Sound in southeast Alaska.
Over the last three decades, this tidewater glacier has retreated more than 20 km and lost about half of its total thickness and volume. The changing climate is thought to have nudged it into retreat in the 1980s, resulting in its end – or terminus – breaking off.
The terminus had previously been supported by a moraine, which is an accumulation of sediment and rock that served as an underwater barrier, helping to keep the glacier stable and insulate it from seawater. With this barrier gone, glacial dynamics took over and it began to flow to the ocean faster, calving large icebergs into the Sound. As this satellite image shows, many icebergs can be seen in the Sound.
This one glacier accounts for nearly half of the ice loss in the Chugach Mountains. However, researchers believe that the Columbia Glacier will stabilise again – probably in a few years – once its terminus retreats into shallower water and it regains traction, which should slow the rate of iceberg calving.
This image, which was captured on 5 August 2017, is also featured on the Earth from Space video programme.
Credits: contains modified Copernicus Sentinel data (2017), processed by ESA,CC BY-SA 3.0 IGO
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 30 April 2020. The image measures about 3 x 15 km.
Credits: ESA/Roscosmos/CaSSIS, CC BY-SA 3.0 IGO