ESA Space Science

The European Space Agency (ESA) reacted promptly to the discovery of comet 3I/ATLAS on 1 July 2025. Soon after they were alerted to its existence by automated detection systems, ESA astronomers began using ground-based telescopes in Hawaii, Chile, and Australia to monitor its progress.

Since then, the comet has been observed by space telescopes close to Earth, including the NASA/ESA Hubble Space Telescope and the NASA/ESA/CSA James Webb Space Telescope.

In recent months, ESA has turned interplanetary voyagers Mars Express, ExoMars Trace Gas Orbiter and the Jupiter Icy Moons Explorer (Juice) in the direction of the comet to make further observations from excellent vantage points.

Follow the links below for more information.

The NASA/ESA Hubble Space Telescope reobserved interstellar comet 3I/ATLAS on 30 November with its Wide Field Camera 3 instrument. At the time, the comet was about 286 million km from Earth. Hubble tracked the comet as it moved across the sky. As a result, background stars appear as streaks of light.

Hubble previously observed 3I/ATLAS in July, shortly after its discovery, and a number of observatories have since studied the comet as well. Observations are expected to continue for several more months as 3I/ATLAS heads out of the solar system.

For the latest updates and FAQs related to comet 3I/ATLAS, see esa.int/3IATLAS.

[Image description: A bright white point sits at the centre of the image, surrounded by a large, soft blue glow that fades gradually into a dark background. Thin, faint streaks appear diagonally across the image, suggesting motion or stars in the distance. The overall effect is of a luminous object in space, radiating light against a deep, dark backdrop.]

Is it an insect? A strange fossil? An otherworldly eye, or even a walnut? No, it’s an intriguing kind of martian butterfly spotted by ESA’s Mars Express.

On 2 December 1995 the ESA/NASA Solar and Heliospheric Observatory (SOHO) blasted into space – on what was supposed to be a two-year mission. 

From its outpost 1.5 million km away from Earth in the direction of the Sun, SOHO enjoys uninterrupted views of our star. It has provided a nearly continuous record of our Sun’s activity for close to three 11-year-long solar cycles. 

Meet Envision. Europe’s next mission to Venus. Planned for launch in 2031.

Envision will study Venus from its core to its upper atmosphere to reveal more about the planet’s history, geological activity, and climate. It will help us understand why Earth’s closest neighbour – in distance as well as in physical characteristics – has evolved into such a hostile planet.

A mission like Envision takes years of planning, involving much teamwork between scientists and engineers. It’s as much a human as a technical endeavour. This video provides a peek behind the scenes at this process.

This short episode is the introduction to a new series called ‘Envision this’, which will follow the development of the mission. Keep an eye on our dedicated Envision website for future episodes.

Smile is a brand-new space mission currently in the making. It will study how Earth responds to the solar wind and solar storms.

At the European Space Agency’s technical heart in the Netherlands, engineers have taken Smile through the final steps of testing and past its qualification and flight acceptance review – confirming that it is ready for launch in spring 2026.

This video let’s viewers peek into the testing and review process. It is the fourth episode in a series of short videos, and includes interviews with David Agnolon (ESA Smile Project Manager), Xia Jiayi (CAS Thermal Engineer), Ana Carillo Pérez (Airbus AIT Electrical and Functional Lead Engineer), Adriana González Castro (ESA Smile Project Controller), Li Jing (CAS Smile Project Manager) and Carole Mundell (ESA Director of Science).

Smile (the Solar wind Magnetosphere Ionosphere Link Explorer) is a joint mission between the European Space Agency and the Chinese Academy of Sciences. Smile is due to launch on a European Vega-C rocket in spring 2026. Follow the latest mission news via esa.int/smile.

Access the related broadcast quality video material 

Access the other episodes of ‘Let’s Smile’

Testing, testing, testing – Let’s Smile (episode 3)

Completing the spacecraft – Let’s Smile (episode 2)

Introducing the Smile mission – Let’s Smile (episode 1)

Smile’s other half arrives – Let’s Smile (action snippet)

The ESA/JAXA BepiColombo mission has been cruising towards Mercury since October 2018. With just one year to go until it arrives at its destination, what has the mission achieved so far? And what can we expect from its two spacecraft after they enter orbit around the Solar System’s smallest and least-explored rocky planet? 

Bepi, Mio and MTM’s adventures continue! What have they achieved on their extraordinary journey to Mercury, planet of extremes and mysteries?

They haven’t been bored, that’s for sure. They snapped cool photos and collected real science data as they flew past Earth, Venus and Mercury – each planet is unique! After witnessing Venus’s blinding heat, flying through Mercury’s freezing shadow, and braving strong winds and radiation coming from the Sun, the trio know they are ready for anything.

In November 2026, the spacecraft will arrive at Mercury to stay. Bepi and Mio will orbit around the little planet to uncover all its mysteries, like: What is it made of? Does it have water? And how does its magnetic field work?

Meet the cartoon characters during their mission training

Marking one year until BepiColombo reaches Mercury

BepiColombo is a joint mission between ESA and the Japan Aerospace Exploration Agency (JAXA), executed under ESA leadership. It is Europe's first mission to Mercury. Launched in 2018, it will arrive at Mercury in November 2026 and begin science operations in early 2027.

Smile has passed its qualification and flight acceptance review, meaning that it meets all requirements for launch. The launch window has been set for 8 April to 7 May 2026.

The Sun is always mesmerising to watch, but Solar Orbiter captured a special treat on camera: a dark â€˜prominence’ sticking out from the side of the Sun.   

The dark-looking material is dense plasma (charged gas) trapped by the Sun's complex magnetic field. It looks dark because it is cooler than its surroundings, being around 10 000 °C compared to the surrounding million-degree plasma.  

When viewed against the background of space, the hovering plasma is referred to as a prominence. When viewed against the Sun's surface, it is called a filament. (In this image you can see examples of both.) 

Solar prominences and filaments extend for tens of thousands of kilometres, several times the diameter of Earth. They can last days or even months. This video shows one hour of footage, sped up to make movement more clearly visible.  

Solar Orbiter recorded this video with its Extreme Ultraviolet Imager (EUI) instrument on 17 March 2025. At the time, the spacecraft was around 63 million km from the Sun, similar to planet Mercury. 

Solar Orbiter is a space mission of international collaboration between ESA and NASA. The EUI instrument is led by the Royal Observatory of Belgium (ROB). 

[Video description: Close-up video of the Sun, filling the left half of the view, its surface covered what looks like moving, glowing hairs accompanied by some short-lived bright arcs. Protruding to the right, in the centre of the video, is dark material that looks almost feathery, with thin streaks flowing both away from and towards the Sun.] 

This shimmering view of interstellar gas and dust was captured by the European Space Agency’s Euclid space telescope. The nebula is part of a so-called dark cloud, named LDN 1641. It sits at about 1300 light-years from Earth, within a sprawling complex of dusty gas clouds where stars are being formed, in the constellation of Orion.

In visible light this region of the sky appears mostly dark, with few stars dotting what seems to be a primarily empty background. But, by imaging the cloud with the infrared eyes of its NISP instrument, Euclid reveals a multitude of stars shining through a tapestry of dust and gas.

This is because dust grains block visible light from stars behind them very efficiently but are much less effective at dimming near-infrared light.

The nebula is teeming with very young stars. Some of the objects embedded in the dusty surroundings spew out material – a sign of stars being formed. The outflows appear as magenta-coloured spots and coils when zooming into the image.

In the upper left, obstruction by dust diminishes and the view opens toward the more distant Universe with many galaxies lurking beyond the stars of our own galaxy.

Euclid observed this region of the sky in September 2023 to fine-tune its pointing ability. For the guiding tests, the operations team required a field of view where only a few stars would be detectable in visible light; this portion of LDN 1641 proved to be the most suitable area of the sky accessible to Euclid at the time.

The tests were successful and helped ensure that Euclid could point reliably and very precisely in the desired direction. This ability is key to delivering extremely sharp astronomical images of large patches of sky, at a fast pace. The data for this image, which is about 0.64 square degrees in size â€“ or more than three times the area of the full Moon on the sky â€“ were collected in just under five hours of observations.

Euclid is surveying the sky to create the most extensive 3D map of the extragalactic Universe ever made. Its main objective is to enable scientists to pin down the mysterious nature of dark matter and dark energy.

Yet the mission will also deliver a trove of observations of interesting regions in our galaxy, like this one, as well as countless detailed images of other galaxies, offering new avenues of investigation in many different fields of astronomy.

[Technical details: The colour image was created from NISP observations in the Y-, J- and H-bands, rendered blue, green and red, respectively. The size of the image is 11 232 x 12 576 pixels. The jagged boundary is due to the gaps in the array of NISP’s sixteen detectors, and the way the observations were taken with small spatial offsets and rotations to create the whole image. This is a common effect in astronomical wide-field images.]

[Image description: The focus of the image is a portion of LDN 1641, an interstellar nebula in the constellation of Orion. In this view, a deep-black background is sprinkled with a multitude of dots (stars) of different sizes and shades of bright white. Across the sea of stars, a web of fuzzy tendrils and ribbons in varying shades of orange and brown rises from the bottom of the image towards the top-right like thin coils of smoke.]