ESO Top News
You can’t judge a star by its protoplanetary disc
This image tells the story of redemption for one lonely star. The young star MP Mus (PDS 66) was thought to be all alone in the Universe, surrounded by nothing but a featureless band of gas and dust called a protoplanetary disc. In most cases, the material inside a protoplanetary disc condenses to form new planets around the star, leaving large gaps where the gas and dust used to be. These features are seen in almost every disc – but not in MP Mus’s.
When astronomers first observed it with the Atacama Large Millimeter/submillimeter Array (ALMA), they saw a smooth, planet-free disc, shown here in the right image. The team, led by Álvaro Ribas, an astronomer at the University of Cambridge, UK, gave this star another chance and re-observed it with ALMA at longer wavelengths that peer even deeper into the protoplanetary disc than before. These new observations, shown in the left image, revealed a gap and a ring that had been obscured in previous observations, suggesting that MP Mus might have company after all.
Meanwhile, another piece of the puzzle was being revealed in Germany as Miguel Vioque, an astronomer at the European Southern Observatory, studied this same star with the European Space Agency’s (ESA’s) Gaia mission. Vioque noticed something suspicious – the star was wobbling. A bit of gravitational detective work, together with insights from the new disc structures revealed by ALMA, showed that this motion could be explained by the presence of a gas giant exoplanet.
Both teams presented their joint results in a new paper published in Nature Astronomy. In what they describe as “a beautiful merging of two groups approaching the same object from different angles”, they show that MP Mus isn’t so boring after all.
[Image description: This is an observation from the ALMA telescope, showing two versions (side-by-side) of a protoplanetary disc. Both discs are bright, glowing yellow-orange objects with a diffused halo against a dark background. The right disc is more smooth and blurry looking. The left disc shows more detail, for example gaps and rings within it.]
Week in images: 07-11 July 2025
Week in images: 07-11 July 2025
Discover our week through the lens
Earth from Space: Lake District, UK
ESA Council receives Anniversary Statement
The Council of the European Space Agency has received the Anniversary Statement as signed by Member States marking 50 years of the agency.
Webb scratches under Cat’s Paw Nebula for third anniversary
To mark its third year of highly productive science, astronomers used the NASA/ESA/CSA James Webb Space Telescope to scratch beyond the surface of the Cat’s Paw Nebula (NGC 6334), a massive, local star-forming region.
Europe's first deep-space optical communication link
The European Space Agency (ESA) successfully established a transmission-reception optical link with NASA’s Deep Space Optical Communications (DSOC) experiment onboard its Psyche mission, located 265 million kilometres away, using two optical grounds stations developed for this purpose in Greece.
Closing the loop: new Space Rider drop test
Week in images: 30 June - 4 July 2025
Week in images: 30 June - 4 July 2025
Discover our week through the lens
Earth from Space: Zanzibar, Tanzania
Antarctic waters getting saltier as sea ice wanes
Using data from ESA’s SMOS satellite, scientists have revealed a surprising shift in the Southern Ocean – surface waters around Antarctica are growing saltier, even as sea ice is diminishing rapidly. This finding defies the norm because melting ice typically freshens ocean surface water.
The implications are far-reaching as changes in this remote region can disrupt global ocean currents, affect climate patterns, and alter ecosystems far beyond the Antarctic.
ESA tracks rare interstellar comet
Astronomers have confirmed the discovery of a rare celestial visitor: a comet from beyond our Solar System.
Officially named 3I/ATLAS, this newly identified interstellar object is only the third of its kind ever observed, following the famous 1I/ʻOumuamua in 2017 and 2I/Borisov in 2019.
Clingy planets can trigger own doom, suspect Cheops and TESS
Astronomers using the European Space Agency’s Cheops mission have caught an exoplanet that seems to be triggering flares of radiation from the star it orbits. These tremendous explosions are blasting away the planet’s wispy atmosphere, causing it to shrink every year.
This is the first-ever evidence for a ‘planet with a death wish’. Though it was theorised to be possible since the nineties, the flares seen in this research are around 100 times more energetic than expected.
MTG-S1 and Copernicus Sentinel-4 mission highlights
Two meteorological missions – Meteosat Third Generation Sounder-1 (MTG-S1) and the Copernicus Sentinel-4 mission – have launched on board a SpaceX Falcon 9 from Cape Canaveral in Florida, US.
Both are world-class Earth observation missions developed with European partners to address scientific and societal challenges.
The MTG-S1 satellite will generate a completely new type of data product, especially suited to nowcasting severe weather events, with three-dimensional views of the atmosphere. It is the second in the MTG constellation to be prepared for orbit and is equipped with the first European operational Infrared Sounder instrument.
Copernicus Sentinel-4 will be the first mission to monitor European air quality from geostationary orbit, providing hourly information that will transform how we predict air pollution across Europe, using its ultraviolet, visible, near-infrared light (UVN) spectrometer.
MTG-S1 and Copernicus Sentinel-4 launch highlights
Two meteorological missions – Meteosat Third Generation Sounder-1 (MTG-S1) and the Copernicus Sentinel-4 mission – have launched on board a SpaceX Falcon 9 from Cape Canaveral in Florida, US.
Both are world-class Earth observation missions developed with European partners to address scientific and societal challenges.
The MTG-S1 satellite will generate a completely new type of data product, especially suited to nowcasting severe weather events, with three-dimensional views of the atmosphere. It is the second in the MTG constellation to be prepared for orbit and is equipped with the first European operational Infrared Sounder instrument.
Copernicus Sentinel-4 will be the first mission to monitor European air quality from geostationary orbit, providing hourly information that will transform how we predict air pollution across Europe, using its ultraviolet, visible, near-infrared light (UVN) spectrometer.
MTG-S1 and Sentinel-4 launch to change how we see our atmosphere
The second of the Meteosat Third Generation (MTG) satellites and the first instrument for the Copernicus Sentinel-4 mission lifted off at 23:04 CEST on Tuesday, 1 July. The satellite is now on its way to monitor Earth’s atmosphere from an altitude of 36 000 km. From this geostationary orbit, the missions can provide game-changing data for forecasting severe storms and air pollution over Europe.
Southern Europe’s land and sea sizzles
A pinch of France in space
ESA astronaut Sophie Adenot selected the French chef Anne-Sophie Pic to develop the bonus food she will bring to the International Space Station during her mission εpsilon.
MTG-S1 satellite hosting the Sentinel-4 instrument is ready for liftoff
The Meteosat Third Generation Sounder (MTG-S1) satellite, which is hosting the instrument for the Copernicus Sentinel-4 mission, has been placed inside the nose cone of the Falcon 9 launch rocket and is ready for the scheduled liftoff at 23:03 CEST on Tuesday, 1 July.
Plato’s eyes meet brain
On 11 June, engineers at OHB’s facilities in Germany joined together the two main parts of ESA’s Plato mission.
They used a special crane to lift Plato’s payload module, housing its 26 ultra-sensitive cameras, into the air and carefully line it up over the service module. The supporting service module contains everything else that the spacecraft needs to function, including subsystems for power, propulsion and communication with Earth.
With millimetre-level precision, the engineers gently lowered the payload module into place. Once perfectly positioned, the team tested the electrical connections.
Finally, they securely closed a panel that connects the payload module to the service module both physically and electronically (seen ‘hanging’ horizontally above the service module in this image). This panel, which opens and closes with hinges, also contains the electronics to process data from the cameras.
Now in one piece, Plato is one step closer to beginning its hunt for Earth-like planets.
In the coming weeks, the spacecraft will undergo tests to ensure its cameras and data processing systems still work perfectly.
Then it will be driven from OHB’s cleanrooms to ESA’s technical heart (ESTEC) in the Netherlands. At ESTEC, engineers will complete the spacecraft by fitting it with a combined sunshield and solar panel module.
Following a series of essential tests to confirm that Plato is fit for launch and ready to work in space, it will be shipped to Europe’s launch site in French Guiana.
The mission is scheduled to launch on an Ariane 6 in December 2026.
Access the related broadcast quality video footage.
ESA’s Plato (PLAnetary Transits and Oscillations of stars) will use 26 cameras to study terrestrial exoplanets in orbits up to the habitable zone of Sun-like stars.
Plato's scientific instrumentation, consisting of the cameras and electronic units, is provided through a collaboration between ESA and the Plato Mission Consortium. This Consortium is composed of various European research centres, institutes and industries, led by the German Aerospace Center (DLR). The spacecraft is being built and assembled by the industrial Plato Core Team led by OHB together with Thales Alenia Space and Beyond Gravity.