ESA Top Multimedia

MTG-S and Sentinel-4 in the cleanroom in Bremen, side view

Sentinel-4: European air quality monitoring for Copernicus

The pierogi challenge

Using data from satellite sensors such as Tropomi on Sentinel-5P and GOME-2 on MetOp along with forecast models, this animation shows concentrations of near-surface ozone every hour over Europe throughout June 2018. It shows a typical summer month with several instances of heavy pollution, for example over the Netherlands and Germany on 7 June. Concentrations often exceed 120 μg/m3, which exceeds the eight-hourly mean limit of European air-quality standards.

The Copernicus Sentinel-4 mission, an ultraviolet, visible, near-infrared light spectrometer carried on the Meteosat Third Generation Sounder satellite in geostationary, provides hourly observations to monitor air quality over Europe. These hourly observations are set to make a breakthrough for air quality monitoring from space.

Watch the latest updates on ESA’s Fly! Feasibility Study with Daniel Neuenschwander, ESA Director of Human and Robotic Exploration, John McFall, Member of the ESA Astronaut Reserve & Fly! Subject Matter Expert, Jerome Reineix, Fly! Study Manager, and Alessandro Alcibiade, Fly! Flight Surgeon.

Announced in November 2022 during the Ministerial Council held in Paris, France, this unique and groundbreaking study is aimed at understanding and challenging the limitations posed by physical disabilities to human spaceflight. Concluded in late 2024, the Fly! Feasibility Study successfully demonstrated it is technically feasible to fly someone with a physical disability, like John’s, on a six-month mission to the International Space Station as a fully integrated crew member. It underpinned the desire to ensure that space exploration is not limited by physical constraints and that every individual can contribute to our collective understanding of the cosmos and of the benefits of spaceflight for life on Earth.

The end of the feasibility study marks the start of the next phase: Fly! Mission Ready . This is an essential step to carry out the first long-term mission for an astronaut with a physical disability.

For Valentine’s Day, the Copernicus Sentinel-2 mission picks out a heart in the landscape north of Mount St Helens in the US state of Washington.

Pierogi space packaging

Meet Biomass – ESA’s next Earth Explorer mission to launch. Carrying the first P-band synthetic aperture radar in space, this new mission is set to deliver crucial information about the state of our forests and how they are changing, and to further our knowledge of the role forests play in the carbon cycle.

Euclid image of a bright Einstein ring around galaxy NGC 6505

Supernova spotting

ESA’s Earth Explorer Biomass is the first satellite to carry a P-band synthetic aperture radar in space to measure forest biomass and height, consistently across the globe and across different forest types. Thanks to the long 70 cm wavelength of P-band, the signal can penetrate through the forest canopy, allowing it to collect information on amounts of different parts of the forest, namely, tree trunks, branches and stems – which is where trees store most of their carbon.

Since carbon makes up roughly half the weight of wood, the mission is extremely important in the quest to reduce uncertainties about the role forests play in the global carbon cycle and in our climate system.

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.

A group of volunteers is spending two months lying in bed—with their feet up and one shoulder always touching the mattress—even while eating, showering, and using the toilet. But why? This extreme bedrest study is helping scientists understand how space travel affects the human body and how to keep astronauts healthy on long missions.

Microgravity causes muscle and bone loss, fluid shifts, and other physiological changes similar to those experienced by bedridden patients on Earth. By studying volunteers here on Earth, researchers can develop better countermeasures for astronauts and even improve treatments for medical conditions like osteoporosis.

In this study, participants are divided into three groups: one stays in bed with no exercise, another cycles in bed to mimic astronaut workouts, and a third cycles while being spun in a centrifuge to simulate artificial gravity. Scientists hope artificial gravity could become a key tool in protecting astronauts during deep-space missions.