
ESA Top Multimedia
HR 8799 System (NIRCam image)

From pebbles to planets
Biomass out of the box
Sara García Alonso | Astronaut Reserve Training, Space biology, Explorer’s Wisdom | ESA Explores #10

Meet Sara García Alonso — biotechnologist, cancer researcher, passionate science communicator and member of ESA’s Astronaut Reserve.
She’s our first guest in this miniseries, where we dive into the journey of the ESA Astronaut Reserve and explore the first part of their Astronaut Reserve Training (ART) at the European Astronaut Centre (EAC). Here, our “ARTists” are learning all about ESA and the International Space Station programme, the European space industry and institutions, and gaining hands-on experience in technical skills like spacecraft systems and robotics, as well as human behaviour, scientific lessons, scuba diving, and survival skills. This interview was recorded in November 2024.
This interview was recorded in November 2024.
Find out more about Sara here and learn about ESA’s Astronaut Reserve Training programme here.
You can also listen to this episode on all major podcast platforms, including Podbean, Apple Podcasts, Spotify, Deezer and more.
Explore more from ESA Explores here.
Earth from Space: Halong Bay, Vietnam
A spiral and a star

ESA's Hera Mission - Mars Flyby and Deimos Encounter Media Briefing

Media representatives were invited to attend a briefing on 13 March 2025 following the Hera mission’s close flyby of Mars and its enigmatic moon, Deimos, on 12 March. The flyby is a significant milestone in Hera’s journey to the binary asteroid system Didymos and a crucial step in the ESA's efforts to develop reliable methods for asteroid deflection and planetary defence.
Images from Hera’s Mars flyby (Official broadcast)

Watch the replay of our Hera mission Mars flyby event. On 12 March 2025, ESA’s Hera mission came to within 5000 km of the surface of the red planet and 300 km of Mars’s more distant and enigmatic moon Deimos. During this flyby, Hera performed observations of both Mars and the city-sized Deimos. Hera then needed to swing its High Gain Antenna back to Earth to transmit its data home. On Thursday, 13 March, these images were premiered by Hera’s science team from ESA’s ESOC mission control centre in Darmstadt, Germany, explaining what they reveal, during our public webcast starting at 11:50 CET. The team was joined by ESA astronaut Alexander Gerst and renowned science fiction writer Andy Weir, author of The Martian and Project Hail Mary, as well as a surprise special guest!
Deimos appears to cross Mars

Space HPC panellists

Speakers at the inauguration of ESA Space HPC at ESRIN, Italy.
The Incredible Adventures of the Hera mission – The cosmic roadtrip

Meet Hera, our very own asteroid detective. Together with two CubeSats – Milani the rock decoder and Juventas the radar visionary – Hera is off on an adventure to explore Didymos, a double asteroid system that is typical of the thousands that pose an impact risk to planet Earth.
In September 2022 NASA’s DART spacecraft tested if it was possible to divert an asteroid by giving it a shove – and found out that it was! Important knowledge, should we wish to avoid going the same way as the dinosaurs. Astronomers can observe from afar how the smaller asteroid’s orbit has shifted since DART’s impact, but there is still a missing piece of the puzzle if we want to fully understand how ‘kinetic impacting’ works in practice. Suitable for kids and adults alike, this episode of ‘The Incredible Adventures of Hera’ explains what ESA’s asteroid detective and its CubeSat assistants are doing on their cosmic roadtrip through space towards the asteroid, and why it involves skimming close to Mars.
Watch the other episodes of The Incredible Adventures of the Hera Mission
Listen to the Sun’s own radio station

Up to several times a day, the Sun blasts bursts of energetic electrons into space, which emit radio waves as they collide with other charged particles. These bursts are picked up by the Radio and Plasma Waves (RPW) instrument on the ESA-led Solar Orbiter spacecraft.
A team at Radboud University/Paris Observatory has now divided five years of RPW data into 15 000 six-hour chunks. This video shows one such chunk of data. As the blasted electrons move further into space, away from the Sun, there are fewer charged particles to interact with, and the radio frequency drops. Each ‘hockey stick’ shape is a real radio burst in action.
In this sonification, the radio waves are converted into sound, with lower frequency radio waves corresponding to lower frequency sound waves. Whenever a radio burst occurs, we hear a ‘pyoong’ sound that gets lower in tone before fading out completely. The timeline has been sped up; the biggest radio burst in the middle of the graph lasted about three hours in real life!
Solar Orbiter spots a solar flare

This dazzling solar flare was captured by the ESA-led Solar Orbiter mission on 30 September 2024.
A solar flare is a tremendous explosion on the Sun that happens when energy stored in ‘twisted’ magnetic fields is suddenly released. In a matter of just a few minutes a solar flare heats material to many millions of degrees and produces bursts of radiation across the electromagnetic spectrum, from radio waves to gamma rays.
The radiation from solar flares directly affects Earth’s upper atmosphere and radio communications. This is why it’s so important that we watch and monitor flares to better understand them. This flare was classified as a medium-sized or ‘M-class’ flare, which can cause brief radio blackouts that affect Earth's polar regions.
The video uses images taken by Solar Orbiter’s Extreme Ultraviolet Imager (EUI) instrument. It was made by scientists at the Royal Observatory of Belgium using the JHelioviewer software, which anyone can use to make their own solar flare movies. All EUI data is accessible through the JHelioviewer application.
Never before has a space mission been able to observe solar flares in such high resolution in space and time. The video is sped up. In reality the flare lasted about 15 minutes.
Sped-up simulation of Hera’s Mars flyby

On 12 March 2025 ESA’s Hera spacecraft for planetary defence performs a flyby of Mars. The gravity of the red planet shifts the spacecraft’s trajectory towards the Didymos binary asteroid system, shortening its trip by months and saving substantial fuel.
This is a simulation of that flyby, with closest approach to Martian moon Deimos taking place at 12:07 GMT and Mars occurring at 12:51 GMT. It was made using SPICE (Spacecraft, Planet, Instrument, C-matrix, Events) software. Produced by a team at ESA’s ESAC European Space Astronomy Centre, this SPICE visualisation is used to plan instrument acquisitions during Hera’s flyby.
Hera comes to around 5000 km from the surface of Mars during its flyby. It will also image Deimos, the smaller of Mars’s two moons, from a minimum 1000 km away (while venturing as close as 300 km). Hera will also image Mars’s larger moon Phobos as it begins to move away from Mars. In this sped-up simulation, Deimos is seen 30 seconds in, at 12:07 GMT, while the more distant star-like Phobos becomes visible at two minutes in, at 12:49 GMT.
The spacecraft employs three of its instruments over the course of these close encounters, all located together on the ‘Asteroid Deck’ on top of Hera:
Hera’s Asteroid Framing Camera is formed of two redundant 1020x1020 pixel monochromatic visible light cameras, used for both navigation and science.
The Thermal Infrared Imager, supplied by the Japanese Aerospace Exploration Agency, JAXA, images at mid-infrared wavelengths to determine surface temperatures.
Hera’s Hyperscout H is a hyperspectral imager, observing in 25 visible and near-infrared spectral bands to prospect surface minerals.
Did you know this mission has its own AI? You can pose questions to our Hera Space Companion!
Flame Nebula in visible and infrared light

Hera asteroid mission’s Mars flyby

On Wednesday 12 March 2025 ESA’s Hera spacecraft for planetary defence performs a flyby of Mars. The gravity of the red planet shifts the spacecraft’s trajectory towards its final destination of the Didymos binary asteroid system, shortening its trip by months and saving substantial fuel.
Watch the livestream release of images from Hera’s flyby by the mission’s science team on Thursday 13 March, starting at 11:50 CET!
Hera comes to around 5000 km from the surface of Mars during its flyby. It will also image Deimos, the smaller of Mars’s two moons, from a minimum 1000 km away (while venturing as close as 300 km). Hera will also image Mars’s larger moon Phobos as it begins to move away from Mars.
Launched on 7 October 2024, Hera on its way to visit the first asteroid to have had its orbit altered by human action. By gathering close-up data about the Dimorphos asteroid, which was impacted by NASA’s DART spacecraft in 2022, Hera will help turn asteroid deflection into a well understood and potentially repeatable technique.
Hera will reach the Didymos asteroid and its Dimorphos moonlet in December 2026. By gathering crucial missing data during its close-up crash scene investigation, Hera will turn the kinetic impact method of asteroid deflection into a well understood technique that could potentially be used for real when needed.
Did you know this mission has its own AI? You can pose questions to our Hera Space Companion!
European engineers give Orion its wings

ESA’s Director General Opening Remarks for International Women’s Day

On 6 March ESA celebrated International Women’s Day with a hybrid event for the whole workforce. The Director General kicked off the event with a welcome message to all the participants highlighting the ESA’s deep commitment to the values of Diversity and Inclusiveness and the many ways the agency is pushing forward the different aspects relevant to gender equality.
Webb wows with incredible detail in star-forming system

Close-up of Proba-3’s Coronagraph, ready to dance

Earth from Space: Tirana, Albania
A spiral of the water snake

Women powering up space
Europe’s human spaceflight ambitions are reaching new heights, and ESA’s Astronaut Reserve is a key part of this journey. Selected in 2022, these talented individuals are undergoing Astronaut Reserve Training (ART) to ensure they are ready for future missions.
Among these remarkable women from across Europe are Meganne Christian, a materials scientist from the UK, Anthea Comellini, an aerospace engineer from Italy, and Carmen Possnig, a medical doctor from Austria, who recently completed their first ART training block at the European Astronaut Centre (EAC) in Cologne, Germany.
Their diverse scientific backgrounds reflect the wide-ranging expertise needed for human spaceflight, whether as part of ESA’s astronaut class, mission planners, or scientists shaping the future of space exploration. Beyond their work with ESA, they are also driving innovation, advancing research, and strengthening the broader space sector. Women play key roles across ESA and beyond, contributing as leaders and experts in these areas.
Meganne, Anthea and Carmen recently completed their first ART training block at the European Astronaut Centre (EAC) in Cologne, Germany. In this image, they are pictured inside a mockup of the Columbus module, Europe’s permanent laboratory on the International Space Station.
The training covered key areas such as human behaviour and performance to develop teamwork and decision-making skills in high-pressure environments. They also received physical fitness training, scuba certification in ESA’s Neutral Buoyancy Facility, and media training to effectively communicate the importance of space exploration to the public.
In addition to technical and operational skills, they explored fundamental science, including biology experiments conducted on the International Space Station. Their training also includes insights into space policy, mission operations, and the latest advancements in space technology.
While members of the Astronaut Reserve are not yet assigned to specific missions, their training ensures that they are prepared for potential future opportunities through commercial spaceflight
The journey continues in the second half of 2025, when the members of ESA’s Astronaut Reserve will return to EAC for the next phase of ART, further building on the skills and knowledge they have gained.
Ariane 6 VA263 liftoff

Smile spacecraft: two become one
Student teams explore ESTEC’s robotics labs

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

Smile is a brand-new space mission currently in the making. It will study space weather and the interaction between the solar wind and Earth’s magnetic environment.
At the European Space Agency’s technical heart in the Netherlands, engineers have spent the last five months unboxing and testing different elements of the spacecraft, and joining the two main parts together. Due to launch by the end of 2025, Smile is now well on its way to being ready for space.
This video provides a glimpse into what we’ve been up to recently. It is the second episode in a series of short videos, and includes interviews with Adriana González Castro (ESA Smile Project Controller), Walfried Raab (ESA Smile Lead Payload Engineer), Sylvain Vey (ESA Smile Instrument and Operations Interface Engineer), Li Jing (CAS Smile Project Manager), Benjamin Vanoutryve (Smile AIT/AIV and Launcher Interface Principal Engineer), and José Ignacio Maestra Onteniente (Airbus Smile AIT Manager).
Access the other episodes of ‘Let’s Smile’
Introducing the Smile mission – Let’s Smile (episode 1)
Smile’s other half arrives – Let’s Smile (action snippet)
Smile (the Solar wind Magnetosphere Ionosphere Link Explorer) is a 50–50 collaboration between the European Space Agency (ESA) and the Chinese Academy of Sciences (CAS).
MSSA and ESA partner for advancing space-based 5G/6G networks

What plants can grow in space?

Do you know the difference between a vegetable, a fruit, and a seed? In this video, we explore the different components of plants, and their varying growth needs and yields, to consider which plants might be best suited for growing on a future space mission.
Second Ariane 6 in the spotlights
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