ESA Space Science

While ESA's Integral was observing the sky, it suddenly spotted a burst of gamma-rays coming from the nearby galaxy M82. Only a few hours later, ESA’s XMM-Newton searched for an afterglow from the explosion but found none. Astronomers realised that the burst must have been an extra-galactic flare from a magnetar, a young neutron star with an exceptionally strong magnetic field.

No sign of Ziggy Stardust – but ESA’s Mars Express has snapped the telltale traces of ‘spiders’ scattered across the southern polar region of Mars.

In celebration of the 34th anniversary of the launch of the legendary NASA/ESA Hubble Space Telescope on 24 April, astronomers took a snapshot of the Little Dumbbell Nebula (also known as Messier 76, M76, or NGC 650/651) located 3400 light-years away in the northern circumpolar constellation Perseus. The photogenic nebula is a favourite target of amateur astronomers.

Have you ever looked up at the night sky and wondered if there are other planets out there beyond our Solar System?

Astronomers recently used a trove of archived images taken by the NASA/ESA Hubble Space Telescope to visually snag a largely unseen population of smaller asteroids in their tracks. The treasure hunt required pursuing 37 000 Hubble images spanning 19 years. The payoff was finding 1701 asteroid trails, with 1031 of those asteroids uncatalogued. About 400 of these uncatalogued asteroids are about below a km in size.

ESA’s Proba-2 captured two partial solar eclipses on 8 April 2024. 

A solar eclipse occurs when the Moon passes between Earth and the Sun, totally or partially blocking the Sun from Earth’s point of view. On 8 April, lucky viewers across North America witnessed the Moon blocking out the Sun in its entirety for a few minutes, while those north and south of the ‘total eclipse path’ witnessed a partial eclipse.  

Throughout the eclipse period, the Moon crossed Proba-2’s field of view twice, appearing as a partial solar eclipse. The satellite flies around 700 km above Earth’s surface in what is called a Sun-synchronous orbit, each orbit lasting around 100 minutes.  

The video was produced from images taken by Proba-2’s SWAP telescope, which observes the Sun in extreme ultraviolet light. At these wavelengths, the turbulent nature of the Sun's surface and corona – the Sun's extended atmosphere – become visible. These measurements have to be made from space, because Earth’s atmosphere doesn’t allow such short wavelengths of light to pass through. 

A total solar eclipse provides a unique opportunity to see the Sun’s corona from Earth's surface, using visible light. As the Moon blocks most of the Sun’s bright light, the faint corona can be discerned. By comparing the SWAP ultraviolet images to what is seen by (visible light) telescopes on Earth, we can learn about the temperature and behaviour of different structures in the corona.  

Other solar missions also made the most of the unique measurement opportunities provided by the eclipse. For example, ESA’s Solar Orbiter was positioned close to the Sun and at a 90-degree angle from Earth’s view throughout the eclipse. This allowed it to complement Earth-based observations by monitoring the Sun’s corona side-on, including any solar eruptions pointing in Earth’s direction.

During a solar eclipse the Earth is plunged into darkness and the Sun’s ghostly atmosphere becomes visible. Scientists travel the globe to experience total solar eclipses, which occur for just a few minutes at a time every 18 months or so. But what exactly causes solar eclipses, and how do scientists try to make their own, including with ESA’s new Proba-3 mission?

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The Euclid mission team was awarded this year’s Space Achievement Award by the Space Foundation, a non-profit organisation founded in 1983 to foster collaboration across the global space community. ESA Director General, Josef Aschbacher (centre), and ESA Director of Science, Carole Mundell (right), collected the prize at the Space Symposium in Colorado Springs, USA, on 8 April at 18:00 MDT (9 April at 2:00 CEST).

The Space Foundation recognised the partnership between ESA and the Euclid Consortium for their forward-thinking approach to global collaboration and team work to advance humankind’s understanding of the Universe.

Euclid is a scientific endeavour involving more than 300 institutes from 13 European countries and the USA, Canada and Japan. It has been made possible by the the work and dedication of more than 3500 people and thanks to the expertise of 80 companies from 21 countries.

Euclid’s quest is to uncover the nature of two mysterious components of our Universe: dark matter and dark energy. The mission will chart how the Universe has expanded and how large-scale structure is distributed across space and time. To achieve these ambitious goals, the space telescope will create the largest, most accurate 3D map of the Universe ever produced across 10 billion years of cosmic time.

Euclid is a European mission, built and operated by ESA, with contributions from NASA. The Member States of ESA together with the Euclid Consortium are responsible for providing the scientific instruments and scientific data analysis. ESA selected Thales Alenia Space as prime contractor for the construction of the satellite and its service module, with Airbus Defence and Space chosen to develop the payload module, including the telescope. NASA provided the detectors of the Near-Infrared Spectrometer and Photometer, NISP. Euclid is a medium-class mission in ESA’s Cosmic Vision Programme.

Image source: Space Foundation

A citizen scientist digging through data from the ESA/NASA Solar and Heliospheric Observatory has found the mission’s 5000th comet.

The tiny comet – indicated between the vertical lines in the inset – belongs to the ‘Marsden group’, named after the British astronomer Brian Marsden, who first recognised the group based on SOHO observations. Marsden group comets are thought to be pieces shed by the much bigger Comet 96P/Machholz, which SOHO observes as it passes close to the Sun every 5.3 years.

This 5000th comet was discovered by Hanjie Tan, an astronomy PhD student in Prague, Czechia. Hanjie has been comet hunting since he was just 13 years old, discovering over 200 comets since 2009.

Hanjie explains how he felt upon spotting this comet in the data: “The Marsden group comets represent only about 1.5% of all SOHO comet discoveries, so finding this one as the 5000th SOHO comet felt incredibly fortunate. It's really exciting to be the first to see comets get bright near the Sun after they've been travelling through space for thousands of years.”

Launched in 1995, SOHO studies the Sun from its interior to its outer atmosphere, providing unique views and investigating the cause of the solar wind. During the last three decades, SOHO has become the most prolific discoverer of comets in astronomical history.

The telescope’s prowess as a comet-hunter was unplanned, but turned out to be an unexpected success. With its clear view of the Sun’s surroundings, SOHO can easily spot a special kind of comet called a sungrazer – so-called because of their close approach to the Sun.

Like most who have discovered comets in SOHO’s data, Hanjie Tan is a volunteer citizen scientist, searching for comets in his free time with the Sungrazer Project. This NASA-funded citizen science project, managed by Karl Battams from the US Naval Research Lab, grew out of the huge number of comet discoveries by citizen scientists early into SOHO’s mission.

“Prior to the launch of the SOHO mission and the Sungrazer Project, there were only a couple dozen sungrazing comets on record – that’s all we knew existed,” said Karl Battams, who is the principal investigator for the Sungrazer Project. “The fact that we’ve finally reached this milestone – 5000 comets – is just unbelievable to me.”

SOHO is a cooperative effort between ESA and NASA. Mission control is based at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. SOHO’s Large Angle and Spectrometric Coronagraph Experiment, or LASCO, which is the instrument that provides most of the comet imagery, was built by an international consortium, led by the US Naval Research Lab.

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SOHO’s 4000th comet

SOHO’s 3000th comet

[Image description: A bright orange circle covers almost the whole image, with a smaller disc in the middle. Out of the smaller disc protrude wisps of the Sun's atmosphere. To the upper right of the inner circle, an inset zooms in on a small square, with vertical lines surrounding a faint smudge.]

In the year 1181 a rare supernova explosion appeared in the night sky, staying visible for 185 consecutive days. Historical records show that the supernova looked like a temporary ‘star’ in the constellation Cassiopeia shining as bright as Saturn.

Ever since, scientists have tried to find the supernova’s remnant. At first it was thought that this could be the nebula around the pulsar (dead star) 3C 58. However closer investigations revealed that the pulsar is older than supernova 1181.

In the last decade, another contender was discovered; Pa 30 is a nearly circular nebula with a central star in the constellation Cassiopeia. It is pictured here combining images from several telescopes. This composite image uses data across the electromagnetic spectrum and shows a new spectacular view of the supernova remnant. Allowing us to marvel at the same object that appeared in our ancestors’ night sky more than 800 years ago.

X-ray observations by ESA’s XMM-Newton (blue) show the full extent of the nebula and NASA’s Chandra X-ray Observatory (cyan) pinpoints its central source. The nebula is barely visible in optical light but shines bright in infrared light, collected by NASA’s Wide-field Infrared Space Explorer (red and pink). Interestingly, the radial structure in the image consists of heated sulphur that glows in visible light, observed with the ground-based Hiltner 2.4 m telescope at the MDM Observatory (green) in Arizona, USA, as do the stars in the background by Pan-STARRS (white) in Hawaii, USA.

Studies of the composition of the different parts of the remnant have led scientists to believe that it was formed in a thermonuclear explosion, and more precisely a special kind of supernova called a sub-luminous Type Iax event. During this event two white dwarf stars merged, and typically no remnant is expected for this kind of explosion. But incomplete explosions can leave a kind of ‘zombie’ star, such as the massive white dwarf star in this system. This very hot star, one of the hottest stars in the Milky Way (about 200 000 degrees Celsius), has a fast stellar wind with speeds up to 16 000 km/s. The combination of the star and the nebula makes it a unique opportunity for studying such rare explosions.

[Image description: A composite image of the remnant of supernova 1181. A spherical bright nebula sits in the middle surrounded by a field of white dotted stars. Within the nebula several rays point out like fireworks from a central star.]

For Gaia’s 10-year anniversary, ESA champion Galactic Chloé and the ESA Gaia team are very happy to collaborate to tell the space mission's story. From paper calculations, to the launch, and to her third data release last year, discover three of the mission's most surprising discoveries and celebrate with us Gaia’s birthday with this video produced by Galactic Studios! 

Discover the video on Youtube 

Focus on Euclid with Laurent Brouard: “I’m going to show you what a telescope that we send into space looks like.”

Laurent Brouard, Project Manager at Airbus Defence and Space, was responsible for building the Euclid payload module (PLM).

In this interview, which took place in a clean room at the Airbus premises in Toulouse, he describes with words, gestures, and the Euclid PLM structural and thermal model how Euclid works.

Did you know that Euclid sees the same part of the sky at the same time in both the infrared and visible wavelengths? Or that in space radiators keep the instruments cold? Have you ever wondered how light “travels” inside Euclid’s telescope?
Listen to Laurent to know more about the technology behind the mission that will map the dark matter and the dark energy of the Universe.

Space Team Europe is an ESA space community engagement initiative to gather European space actors under the same umbrella sharing values of leadership, autonomy, and responsibility.

©  ESA - European Space Agency

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Focus on Euclid with Guadalupe Cañas Herrera: “I’m exactly where I’ve always wanted to be.”

Guadalupe Cañas Herrera, an ESA Internal Research Fellow currently working for ESA’s Euclid mission at ESTEC, the Netherlands, describes in this interview her personal and professional trajectory.

Passionate about space since her early childhood, she has spent endless nights looking at the stars. Now, this theoretical physicist develops her activities within the Euclid Scientific Consortium to establish the quantity of dark matter and dark energy existing in the Universe.

Listen to Guadalupe for a vivid account from a vocational scientist and an ardent defender of scientific collaboration.

Space Team Europe is an ESA space community engagement initiative to gather European space actors under the same umbrella sharing values of leadership, autonomy, and responsibility.

Access the other Space Team Europe for Euclid videos

Find more videos from Space Team Europe.