European Space Agency

With the first Copernicus Sentinel-2 satellite in orbit since 2015 and the second since 2017, engineers are busy preparing the mission’s follow-on pair to eventually pick up the baton to supply images for a myriad of applications from food security to monitoring the decline of Earth’s ice. Slated for launch at the beginning of 2024, Sentinel-2C has just started a punishing five-month testing programme to ensure that it is fit for its life in space. View the full article

Week in images: 02 - 06 August 2021 Discover our week through the lens View the full article

Image: Crater trio View the full article

Forests are not only key to moderating our climate by sequestering atmospheric carbon, but they also create a cooling effect by increasing low-level cloud. A first global assessment using satellite observations has shown that for two-thirds of the world, afforestation increases low-level cloud cover, with the effect being strongest over evergreen needleleaf forest. View the full article

Russia has the largest area of forest on the planet, with more than a fifth of the world's trees. A new study, led by Russian scientists using data from ESA’s Climate Change Initiative, has produced new estimates of biomass contained in Russian forests, and confirms that the vast forested area is storing more carbon than previously estimated. View the full article

Image: This map generated using data from Copernicus Sentinel-3 shows the temperature of the land surface on 2 August 2021. View the full article

Image: Captured by the Copernicus Sentinel-3 mission on 30 July 2021, this image shows smoke billowing from several fires along the southern coast of Turkey. View the full article

Solar Orbiter and BepiColombo are set to make space history with two Venus flybys just 33 hours apart on 9 and 10 August. View the full article

The first science tests for the ExoMars rover replica kicked off after several weeks of driving tests around the Mars Terrain Simulator at the ALTEC premises in Turin, Italy. View the full article

“I am finding it magical every day, but there is also a lot of routine,” says ESA astronaut Thomas Pesquet reflecting on his first 100 days aboard the International Space Station during his second mission. In total, Thomas has logged 296 days in space. View the full article

A sophisticated telecommunications satellite that can be completely repurposed while in space has launched. View the full article

Europe’s Ariane 5 has delivered two telecom satellites Star One D2 and Eutelsat Quantum into their planned transfer orbits. View the full article

Video: 00:00:49 The first flight of Ariane 5 in 2021 delivers two satellites including the ESA-backed telecommunications satellite Eutelsat Quantum into space. View the full article

Week in images: 26 - 30 July 2021 Discover our week through the lens View the full article

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

Video: 00:04:00 ESA's Jupiter Icy moons Explorer, Juice, has successfully completed rigorous thermal tests simulating the extreme coldness of space and the warmth of the Sun at ESA’s test centre ESTEC, in The Netherlands. The spacecraft underwent a month of round-the-clock testing and monitoring in the Large Space Simulator, which recreates the vacuum of space and is able to simulate both hot and cold space environments. The spacecraft was subjected to temperatures ranging from 250 degrees to minus 180 degrees Celsius, showing that it can survive its journey in space. Juice will launch in 2022 to our Solar System’s largest planet. It will spend over four years studying Jupiter’s atmosphere, magnetosphere and its icy moons Europa, Callisto and Ganymede, investigating whether the moons’ subsurface oceans are habitable for life. This film contains interviews with Pauline Ravily – Airbus Thermal Architect, Eduardo Bernar - European Test Services, ESA, and ESA's Juice Project Scientist, Olivier Witasse. View the full article

Image: Jupiter mission passes space vacuum test View the full article

Image: For the first time, astronomers have seen light coming from behind a black hole. Using ESA’s XMM-Newton and NASA’s NuSTAR space telescopes, an international team of scientists led by Dan Wilkins of Stanford University in the USA observed extremely bright flares of X-ray light coming from around a black hole. The X-ray flares echoed off of the gas falling into the black hole, and as the flares were subsiding, the telescopes picked up fainter flashes, which were the echoes of the flares bouncing off the gas behind the black hole. This supermassive black hole is 10 million times as massive as our Sun and located in the centre of a nearby spiral galaxy called I Zwicky 1, 800 million light-years away from Earth. The astronomers did not expect to see anything from behind the black hole, since no light can escape from it. But because of the black hole’s extreme gravity warping the space around it, light echoes from behind the black hole were bent around the black hole, making them visible from XMM and NuSTAR’s point of view. The discovery began with the search to find out more about the mysterious ‘corona’ of the black hole, which is the source of the bright X-ray light. Astronomers think that the corona is a result of gas that falls continuously into the black hole, where it forms a spinning disk around it – like water flushing down a drain. This gas disk is heated up to millions of degrees and generates magnetic fields that get twisted into knots by the spinning black hole. When the magnetic field gets tied up, it eventually snaps, releasing the energy stored within it. This heats everything around it and produces the corona of high energy electrons that produce the X-ray light. The X-ray flare observed from I Zwicky 1 was so bright that some of the X-rays shone down onto the disk of gas falling into the black hole. The X-rays that reflected on the gas behind the black hole were bent around the black hole, and these smaller flashes arrived at the telescopes with a delay. These observations match Einstein’s predictions of how gravity bends light around black holes, as described in his theory of General Relativity. The echoes of X-rays from the disk have specific ‘colours’ of light and as the X-rays travel around the black hole, their colours change slightly. Because the X-ray echoes have different colours and are seen at different times, depending where on the disk they reflected from, they contain a lot of information about what is happening around a black hole. The astronomers want to use this technique to create a 3D map of the black hole surroundings. Another mystery to be solved in future studies is how the corona produces such bright X-ray flares. The mission to characterise and understand black hole coronas will continue with XMM-Newton and ESA’s future X-ray observatory, Athena (Advanced Telescope for High-ENergy Astrophysics). The team published their findings in Nature. DOI: 10.1038/s41586-021-03667-0 View the full article

Future rockets could fly with tanks made of lightweight carbon fibre reinforced plastic thanks to ground-breaking research carried out within ESA’s Future Launchers Preparatory Programme. View the full article

Follow the launch on 30 July of a sophisticated telecommunications satellite capable of being completely repurposed while in space. View the full article

ESA has successfully operated a spacecraft with Europe’s next-generation mission control system for the first time. The powerful software, named the 'European Ground System - Common Core' (EGS-CC), will be the ‘brain’ of all European spaceflight operations in the years to come, and promises new possibilities for how future missions will fly. View the full article

A European telecommunications satellite that can be completely repurposed while in orbit has been placed on board a rocket ready for launch on 30 July. View the full article

Image: Duneside view of ESA's technical heart View the full article

Week in images: 19 - 23 July 2021 Discover our week through the lens View the full article

Long-term studies of ozone and water vapour in the atmosphere of Mars could lead to better understanding of atmospheric chemistry for the Earth. A new analysis of data from ESA's Mars Express mission has revealed that our knowledge of the way these atmospheric gases interact with each other is incomplete. View the full article