ESA Space Science

This image shows Webb’s recent observation of the asteroid 2024 YR4 using both its Near-Infrared Camera (NIRCam) and Mid-Infrared Instrument (MIRI). Data from NIRCam shows reflected light, while the MIRI observations show thermal light.

On 8 March 2025, the NASA/ESA/CSA James Webb Space Telescope turned its watchful eye toward asteroid 2024 YR4, which we now know poses no significant threat to Earth in 2032 and beyond.

This is the smallest object targeted by Webb to date, and one of the smallest objects to have its size directly measured.

Observations were taken to study the thermal properties of 2024 YR4, including how quickly it heats up and cools down and how hot it is at its current distance from the Sun. These measurements indicate that this asteroid does not share properties observed in larger asteroids. This is likely a combination of its fast spin and lack of fine-grained sand on its surface. Further research is needed, however this is considered consistent with a surface dominated by rocks that are roughly fist-sized or larger.

Asteroid 2024 YR4 was recently under close watch by the team at ESA's Near Earth Objects Coordination Centre, located in Italy. Planetary defence experts from the Agency's Space Safety programme worked with NASA and the international asteroid community to closely watch this object and refine its orbit, which was eventually determined to not pose a risk of Earth impact. Read details on this unusual campaign via ESA's Rocket Science blog and in news articles here and here.

Webb’s observations indicate that the asteroid measures roughly 60 meters (comparable to the height of a 15-story building).

The new observations from Webb not only provide unique information about 2024 YR4’s size, but can also complement ground-based observations of the object's position to help improve our understanding of the object’s orbit and future trajectory.

Note: This post highlights data from Webb science in progress, which has not yet been through the peer-review process.

[Image description: A collage of three images showing the black expanse of space. Two-thirds of the collage is taken up by the black background sprinkled with small, blurry galaxies in orange, blue, and white. There are two images in a column at the right side of the collage. On the right side of the main image, not far from the top, a very faint dot is outlined with a white square. At the right, there are two zoomed in views of this area. The top box is labeled NIRCam and shows a fuzzy dot at the center of the inset. The bottom box is labeled MIRI and shows a fuzzy pinkish dot.]

For over a decade, ESA’s Gaia mission has mapped our galaxy with stunning precision—rewriting the story of the Milky Way. As its mission enters a new phase, we look back at its most groundbreaking discoveries.

The European Space Agency (ESA) has powered down its Gaia spacecraft after more than a decade spent gathering data that are now being used to unravel the secrets of our home galaxy.

On 27 March 2025, Gaia’s control team at ESA’s European Space Operations Centre carefully switched off the spacecraft’s subsystems and sent it into a ‘retirement orbit’ around the Sun.

Though the spacecraft’s operations are now over, the scientific exploitation of Gaia’s data has just begun.

Using the unique infrared sensitivity of the NASA/ESA/CSA James Webb Space Telescope, researchers can examine ancient galaxies to probe secrets of the early Universe. Now, an international team of astronomers has identified bright hydrogen emission from a galaxy in an unexpectedly early time in the Universe’s history. The surprise finding is challenging researchers to explain how this light could have pierced the thick fog of neutral hydrogen that filled space at that time.

Aside from sunlight, the Sun sends out a gusty stream of particles called the solar wind. The ESA-led Solar Orbiter mission is the first to capture on camera this wind flying out from the Sun in a twisting, whirling motion. The solar wind particles spiral outwards as if caught in a cyclone that extends millions of kilometres from the Sun.

Solar wind rains down on Earth's atmosphere constantly, but the intensity of this rain depends on solar activity. More than just a space phenomenon, solar wind can disrupt our telecommunication and navigation systems.

Solar Orbiter is on a mission to uncover the origin of the solar wind. It uses six imaging instruments to watch the Sun from closer than any spacecraft before, complemented by in situ instruments to measure the solar wind that flows past the spacecraft.

This video was recorded by the spacecraft's Metis instrument between 12:18 and 20:17 CEST on 12 October 2022. Metis is a coronagraph: it blocks the direct light coming from the Sun's surface to be able to see the much fainter light scattering from charged gas in its outer atmosphere, the corona.

Metis is currently the only instrument able to see the solar wind's twisting dance. No other imaging instrument can see – with a high enough resolution in both space and time – the Sun's inner corona where this dance takes place. (Soon, however, the coronagraph of ESA's Proba-3 mission might be able to see it too!)

The research paper that features this data, ‘Metis observations of Alfvénic outflows driven by interchange reconnection in a pseudostreamer’ by Paolo Romano et al. was published today in The Astrophysical Journal.

Solar Orbiter is a space mission of international collaboration between ESA and NASA, operated by ESA.

[Technical details: The starting image of the video shows the full view of Solar Orbiter's Metis coronagraph in red, with an image from the spacecraft's Extreme Ultraviolet Imager in the centre (yellow). Zooming to the top left of this view, we see a video derived from Metis observations. The vertical edge of the video spans 1 274 000 km, or 1.83 solar radii. The contrast in the Metis video has been enhanced by using a ‘running difference’ technique: the brightness of each pixel is given by the average pixel brightness of three subsequent frames, minus the average pixel brightness of the three preceding frames. This processing makes background stars appear as horizontal half-dark, half-light lines. Diagonal bright streaks and flashes are caused by light scattering from dust particles close to the coronagraph.] 

The NASA/ESA/CSA James Webb Space Telescope has captured a beautiful juxtaposition of the nearby protostellar outflow known as Herbig-Haro 49/50 with a perfectly positioned, more distant spiral galaxy. Due to the close proximity of this Herbig-Haro object to Earth, this new composite infrared image of the outflow from a young star allows researchers to examine details on small spatial scales like never before. With Webb, we can better understand how the jet activity associated with the formation of young stars can affect the environment surrounding them.

The European Space Agency’s Euclid mission has scouted out the three areas in the sky where it will eventually provide the deepest observations of its mission.

In just one week of observations, with one scan of each region so far, Euclid already spotted 26 million galaxies. The farthest of those are up to 10.5 billion light-years away.

In the coming years, Euclid will pass over these three regions tens of times, capturing many more faraway galaxies, making these fields truly ‘deep’ by the end of the nominal mission in 2030.

The first glimpse of 63 square degrees of the sky, the equivalent area of more than 300 times the full Moon, already gives an impressive preview of the scale of Euclid’s grand cosmic atlas when the mission is complete. This atlas will cover one-third of the entire sky – 14 000 square degrees – in this high-quality detail.

Explore the three deep field previews in ESASky:

-          Euclid Deep Field South

-          Euclid Deep Field Fornax:

-          Euclid Deep Field North:

Read more: Euclid opens data treasure trove, offers glimpse of deep fields

On 19 March 2025, the European Space Agency’s Euclid mission released its first batch of survey data, including a preview of its deep fields. Here, hundreds of thousands of galaxies in different shapes and sizes take centre stage and show a glimpse of their large-scale organisation in the cosmic web.

The European Space Agency is releasing the first catalogue of astronomical data from the Euclid space telescope, including three new enormous image mosaics with zoom-ins. Follow the reveal live on Wednesday 19 March at 11:00 BST / 12:00 CET.

Back in 2023, we reported on Solar Orbiter’s discovery of tiny jets near the Sun’s south pole that could be powering the solar wind. The team behind this research has now used even more data from the European Space Agency’s prolific solar mission to confirm that these jets exist all over dark patches in the Sun’s atmosphere, and that they really are a source of not only fast but also slow solar wind.

The newfound jets can be seen in this sped-up video as hair-like wisps that flash very briefly, for example within the circled regions of the Sun's surface. In reality they last around one minute and fling out charged particles at about 100 km/s.

The surprising result is published today in Astronomy & Astrophysics, highlighting how Solar Orbiter’s unique combination of instruments can unveil the mysteries of the star at the centre of our Solar System.

The solar wind is the never-ending rain of electrically charged particles given out by the Sun. It pervades the Solar System and its effects can be felt on Earth. Yet despite decades of study, its origin remained poorly understood. Until now.

The solar wind comes in two main forms: fast and slow. We have known for decades that the fast solar wind comes from the direction of dark patches in the Sun’s atmosphere called coronal holes – regions where the Sun’s magnetic field does not turn back down into the Sun but rather stretches deep into the Solar System.

Charged particles can flow along these ‘open’ magnetic field lines, heading away from the Sun, and creating the solar wind. But a big question remained: how do these particles get launched from the Sun in the first place?

Building upon their previous discovery, the research team (led by Lakshmi Pradeep Chitta at the Max Planck Institute for Solar System Research, Germany) used Solar Orbiter’s onboard ‘cameras’ to spot more tiny jets within coronal holes close to the Sun’s equator.

By combining these high-resolution images with direct measurements of solar wind particles and the Sun’s magnetic field around Solar Orbiter, the researchers could directly connect the solar wind measured at the spacecraft back to those exact same jets.

What’s more, the team was surprised to find not just fast solar wind coming from these jets, but also slow solar wind. This is the first time that we can say for sure that at least some of the slow solar wind also comes from tiny jets in coronal holes – until now, the origin of the solar wind had been elusive.

The fact that the same underlying process drives both fast and slow solar wind comes as a surprise. The discovery is only possible thanks to Solar Orbiter’s unique combination of advanced imaging systems, as well as its instruments that can directly detect particles and magnetic fields.

The measurements were taken when Solar Orbiter made close approaches to the Sun in October 2022 and April 2023. These close approaches happen roughly twice a year; during the next ones, the researchers hope to collect more data to better understand how these tiny jets ‘launch’ the solar wind.

Solar Orbiter is a space mission of international collaboration between ESA and NASA, operated by ESA. This research used data from Solar Orbiter’s Extreme Ultraviolet Imager (EUI), Polarimetric and Helioseismic Imager (PHI), Solar Wind Plasma Analyser (SWA) and Magnetometer (MAG). Find out more about the instruments Solar Orbiter is using to reveal more about the Sun.

Read our news story from 2023 about how Solar Orbiter discovered tiny jets that could power the solar wind

Read more about how Solar Orbiter can trace the solar wind back to its source region on the Sun

Access the related broadcast quality video material.

Using data from the European Space Agency’s Gaia mission, scientists have found a huge exoplanet and a brown dwarf. This is the first time a planet has been uniquely discovered by Gaia’s ability to sense the gravitational tug or ‘wobble’ the planet induces on a star. Both the planet and brown dwarf are orbiting low-mass stars, a scenario thought to be extremely rare.

Read more.

Access the related animations: Gaia-4b / Gaia-5b

Access the related broadcast quality video material.