European Space Agency

Euclid’s two instruments have captured their first test images. The mesmerising results indicate that the space telescope will achieve the scientific goals that it has been designed for – and possibly much more. View the full article

Image: 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. Find out more Slider comparison image [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.] View the full article

An advanced broadband satellite providing high-speed internet services that demonstrate next-generation 5G connectivity has passed its initial in-orbit tests. View the full article

Surpassing scientific expectations and exceeding its planned life in orbit, the Aeolus wind mission has been hailed as one of ESA’s most successful Earth observation missions. And now, its end will go down in history too, thanks to the ingenuity of the Agency’s mission control team who guided this remarkable satellite down to Earth’s atmosphere for a safe reentry. View the full article

Image: Aeolus control team wraps up successful reentry operations View the full article

Week in images: 24-28 July 2023 Discover our week through the lens View the full article

Video: 00:01:47 In the month after its launch on 1 July, Euclid has travelled 1.5 million kilometres from Earth towards the Sun-Earth Lagrange point L2, meaning it has ‘arrived’ at its destination orbit. This animation showcases the orbits of Euclid (green), the James Webb Space Telescope (blue), and the Gaia mission (yellow) around this unique position in space. The positions of the spacecraft in this animation don’t correspond to their current positions in space. Located about 1.5 million kilometres from Earth in the opposite direction from the Sun, L2 is about four times further away than our Moon. Several other space missions like Webb and Gaia also orbit L2 as it offers the perfect vantage point to study the Universe. At L2, the spacecraft can keep the Sun, Earth and Moon behind them at all times, so they don’t interfere with observations, while at the same time getting a clear view of deep space and pointing an antenna back to Earth to remain in close communication. Euclid and Webb’s halo orbit around L2 is big. In terms of distance, the ‘radius’ of Euclid’s orbit varies from about 400 000 kilometres at its closest to the centre, and up to 800 000 kilometres at its furthest. By the time Euclid has completed one full revolution around L2, the Moon will have circled the Earth six times. Gaia orbits L2 in a Lissajous orbit, with a maximum distance of around 350 000 km from its centre. The region around L2 is big and even though the orbits of these spacecraft seem to cross in the animation, in reality there is plenty of space and a collision can be easily avoided. For example, Webb and Gaia are between 400 000 and 1 100 000 km apart, depending on where they are in their respective orbits. View the full article

Image: The Copernicus Sentinel-1 mission takes us over the Río de la Plata estuary between Argentina and Uruguay. View the full article

Image: Astronaut Andreas Mogensen undergoing VR training for EVA emergencies View the full article

When astronauts return to the Moon they will be bringing along a new generation of spacesuits, designed to withstand the harsh conditions of the lunar surface. But in keeping their human occupants safe and comfortable, these suits might also become a fertile environment for harmful microbial life – especially as astronauts will potentially be sharing suits with one another. View the full article

Aeolus reentry - LIVE Get rolling updates on the Aeolus reentry, on the Rocket Science blog View the full article

Video: 00:46:24 On Tuesday 25 July, the four crew members of Crew-7, Jasmin Moghbeli (NASA), Andreas Mogensen (ESA), Satoshi Furukawa (JAXA) and Konstantin Borisov (Roscosmos) hosted a news conference where they talk about their upcoming mission to the International Space Station. View the full article

Image: Webb snaps detailed infrared image of actively forming stars View the full article

Video: 00:02:42 After a remarkable life in orbit, Aeolus is out of fuel and out of time – it’s returning to Earth this week. Planned and built before any regulations were put in place on ‘end-of-life’ disposal, the Earth Explorer was designed to naturally return through our atmosphere. After months of detailed planning and analysis, ESA together with industrial partners has designed a complex and never-before-performed set of manoeuvres to control, as much as possible, Aeolus’ fall. The assisted reentry attempt is built on four main phases, now begun at ESA’s mission control: Phase I: once Aeolus has fallen naturally to 280 km, the first manoeuvre is performed – the largest in the mission’s five years in orbit. The main objectives are to lower the satellite down to 250 km and to check how the satellite behaves when executing a large manoeuvre at such low altitudes – more than three times the size of any performed during routine operations. Phase II: after three to five days, a series of four manoeuvres will lower Aeolus’s ‘perigee altitude’ – the point in orbit closest to Earth – down to an altitude of about 150 km. Phase III: a final manoeuvre will lower [LJ1] Aeolus to a perigee altitude of 120 km. Phase IV: in the final, shortest phase, Aeolus the spacecraft becomes space debris, completing its final descent in just a few Earth revolutions. In this animation, round regions temporarily lit up in bright green show the moments that Aeolus is in contact with antennas on Earth. It is in these periods that mission control is in touch with the satellite and can send up commands and get its data down. Aeolus is repeatedly turned, or ‘slewed’ by 180° in order to switch from the routine orientation (or ‘attitude’), in which the satellite’s ‘X-band’ antenna points toward Earth and the GPS can function to track the mission – crucial to maintaining knowledge of its position – and the ‘retrograde’ attitude. This second, ‘upside down’ position is necessary for the thrusters to fire in the opposite direction to Aeolus’s flight direction, causing it to lose energy and lower in orbit. While the ultimate goal is for the spacecraft to burn up as it reenters through the atmosphere, teams need to keep it functioning long enough that they can continue to send up commands and control it on its path. After the final commands are sent, Aeolus will be ‘passivated’. Passivation is when any energy onboard a spacecraft is removed, for example, its propellant or batteries. Doing this prevents explosions and fragmentation events, that could cause the release of lots of pieces of unwanted space debris. For Aeolus, already out of fuel, it will simply be turned off. After this point, teams at mission control will continue to monitor the situation until Aeolus’s ultimate reentry location is confirmed. For rolling updates on Aeolus's reentry, follow ‘Aeolus reentry: live’ on the Rocket Science blog. Music: Yesterday’s Hero by Steve Rothery, published by Tunecore. Used with permission of Steve Rothery. View the full article

On 10 July 2023, a volcano some 30 km from Iceland’s capital, Reykjavik, erupted following heightened seismic activity in the area. Satellites orbiting above us have captured the molten lava and smoke plume puffing from the Litli-Hrútur volcano. View the full article

Astronaut Frank Rubio aboard the International Space Station collaborated with a small team of robots on Earth to accomplish a complex task – a first test of a new approach to combine human and robotic capabilities for our return to the Moon and beyond. View the full article

Satellites will soon be used to keep an independent eye on airborne planes, under a deal agreed between ESA and Spire Global, a company that provides space-based data, analytics and space services. View the full article

Globally, more than 70% of the freshwater withdrawn from Earth’s surface or from underground is used to irrigate crops. The need to produce more food for a growing population against the backdrop of climate change is challenging enough, but satellites reveal that extracting water doesn’t just affect the local environment – there are knock-on consequences for many aspects of the Earth system. View the full article

Teams preparing Ariane 6 for its inaugural flight successfully completed for the first time a launcher preparation and countdown sequence, on 18 July at Europe’s Spaceport in Kourou, French Guiana. View the full article

New measurements by the NASA/ESA/CSA James Webb Space Telescope’s Mid-InfraRed Instrument (MIRI) has detected water vapour in the inner disc of the system PDS 70, located 370 light-years away. This is the first detection of water in the terrestrial region of a disc already known to host two or more protoplanets. View the full article

Image: Rhodes wildfire forces thousands to flee View the full article

Image: New Galileo station goes on duty View the full article

Week in images: 17-21 July 2023 Discover our week through the lens View the full article

Video: 00:05:00 ESA’s wind mission Aeolus is coming home. After five years of improving weather forecasts, the satellite will return in a first-of-its-kind assisted reentry. At ESA’s Space Operations Centre in Germany, mission control will use the satellite’s remaining fuel to steer Aeolus during its return to Earth. Find out more about the mission, its successes and how Aeolus is paving the way for safe reentries. View the full article

Image: This Copernicus Sentinel-2 image highlights the colours of autumn over the southern part of New York state in the US. View the full article