ESA Space Science

Listen to the ESA/JAXA BepiColombo spacecraft as it flew past Mercury on 8 January 2025. This sixth and final flyby used the little planet's gravity to steer the spacecraft on course for entering orbit around Mercury in 2026. 

What you can hear in the sonification soundtrack of this video are real spacecraft vibrations measured by the Italian Spring Accelerometer (ISA) instrument. The accelerometer data have been shifted in frequency to make them audible to human ears – one hour of measurements have been sped up to one minute of sound.  

BepiColombo is always shaking ever so slightly: fuel is slightly sloshing, the solar panels are vibrating at their natural frequency, heat pipes are pushing vapour through small tubes, and so forth. This creates the eerie underlying hum throughout the video.  

But as BepiColombo gets closer to Mercury, ISA detects other forces acting on the spacecraft. Most scientifically interesting are the audible shocks that sound like short, soft bongs. These are caused by the spacecraft responding to entering and exiting Mercury's shadow, where the Sun's intense radiation is suddenly blocked. One of ISA's scientific goals is to monitor the changes in the ‘solar radiation pressure’ – a force caused by sunlight striking BepiColombo as it orbits the Sun and, eventually, Mercury. 

The loudest noises – an ominous ‘rumbling’ – are caused by the spacecraft's large solar panels rotating. The first rotation occurs in shadow at 00:17 in the video, while the second adjustment at 00:51 was also captured by one of the spacecraft’s monitoring cameras. 

Faint sounds like wind being picked up in a phone call, which grow more audible around 30 seconds into the video, are caused by Mercury's gravitational field pulling the nearest and furthest parts of the spacecraft by different amounts. As the planet's gravity stretches the spacecraft ever so slightly, the spacecraft responds structurally. At the same time, the onboard reaction wheels change their speed to maintain the spacecraft's orientation, which you can hear as a frequency shift in the background.    

This is the last time that many of these effects can be measured with BepiColombo's largest solar panels, which make the spacecraft more susceptible to vibrations. The spacecraft module carrying these panels will not enter orbit around Mercury with the mission's two orbiter spacecraft. 

The video shows an accurate simulation of the spacecraft and its route past Mercury during the flyby, made with the SPICE-enhanced Cosmographia spacecraft visualisation tool. The inset that appears 38 seconds into the video shows real photographs taken by one of BepiColombo's monitoring cameras.

Read more about BepiColombo's sixth Mercury flyby 

Access the related broadcast quality video material.

The largest photomosaic of the Andromeda galaxy, assembled from NASA/ESA Hubble Space Telescope observations, unveils hundreds of millions of stars. It took more than 10 years to collect data for this colorful portrait of our neighbouring galaxy and was created from more than 600 snapshots. This stunning, colourful mosaic captures the glow of 200 million stars, and is spread across roughly 2.5 billion pixels.

This is a new artist’s animation of our galaxy, the Milky Way, based on data from ESA’s Gaia space telescope.

Gaia has changed our impression of the Milky Way. Even seemingly simple ideas about the nature of our galaxy’s central bar and the spiral arms have been overturned. Gaia has shown us that it has more than two spiral arms and that they are less prominent than we previously thought. In addition, Gaia has shown that its central bar is more inclined with respect to the Sun.

No spacecraft can travel beyond our galaxy, so we can’t take a selfie, but Gaia is giving us the best insight yet of what our home galaxy looks like. Once all of Gaia’s observations collected over the past decade are made available in two upcoming data releases, we can expect an even sharper view of the Milky Way.

Click here to download the still image of the Milky Way.

The European Space Agency’s Milky Way-mapper Gaia has completed the sky-scanning phase of its mission, racking up more than three trillion observations of about two billion stars and other objects over the last decade to revolutionise the view of our home galaxy and cosmic neighbourhood.

The European Space Agency's XMM-Newton has detected rapidly fluctuating X-rays coming from the very edge of a supermassive black hole in the heart of a nearby galaxy. The results paint a fascinating picture that defies how we thought matter falls into such black holes, and points to a potential source of gravitational waves that ESA’s future mission, LISA, could see.

On 8 January 2025, the ESA/JAXA BepiColombo mission flew past Mercury for the sixth time, successfully completing the final ‘gravity assist manoeuvre’ needed to steer it into orbit around the planet in late 2026. The spacecraft flew just a few hundred kilometres above the planet's north pole. Close-up images expose possibly icy craters whose floors are in permanent shadow, and the vast sunlit northern plains.

At the start of this new year, we look back at close-up pictures and solar flare data recorded by the ESA-led Solar Orbiter mission over the last three years. See and hear for yourself how the number of flares and their intensity increase, a clear sign of the Sun approaching the peak of the 11-year solar cycle. 

This video combines ultraviolet images of the Sun's outer atmosphere (the corona, yellow) taken by Solar Orbiter's Extreme Ultraviolet Imager (EUI) instrument, with the size and locations of solar flares (blue circles) as recorded by the Spectrometer/Telescope for Imaging X-rays (STIX) instrument. The accompanying audio is a sonification based on the detected flares and the spacecraft's distance to the Sun.   

Solar Orbiter moves on an elliptical path around the Sun, making a close approach to our star every six months. We can see this in the video from the spacecraft's perspective, with the Sun moving closer and farther over the course of each year. In the sonification, this is represented by the low background humming that loudens as the Sun gets closer and becomes quieter as it moves further away. (There are some abrupt shifts in distance visible in the video, as it skips over dates where one or both instruments were inactive or collecting a different type of data.)  

The blue circles represent solar flares: bursts of high-energy radiation of which STIX detects the X-rays. Flares are sent out by the Sun when energy stored in 'twisted' magnetic fields (usually above sunspots) is suddenly released. The size of each circle indicates how strong the flare is, with stronger flares sending out more X-rays. We can hear the flares in the metallic clinks in the sonification, where the sharpness of the sound corresponds to how energetic the solar flare is. 

Many thanks to Klaus Nielsen (DTU Space / Maple Pools) for making the sonification in this video. If you would like to hear more sonifications and music by this artist, please visit: https://linktr.ee/maplepools 

Solar Orbiter is a space mission of international collaboration between ESA and NASA, operated by ESA. 

An ethereal dance of misty clouds of interstellar dust with a myriad of distant stars and galaxies speckled like paint drops over a black canvas. This is a sonification of a breathtaking image taken by ESA's Euclid space telescope of the young star-forming region Messier 78. 

The sonification offers a different representation of the data collected by Euclid, and lets us explore the stellar nurseries in M78 through sound. Close your eyes and listen to let the cosmic image be drawn by your mind’s eye, or watch as the traceback line in this video follows the sounds to colour the image from left to right.  

The twinkling sounds of various pitches and volumes represent the galaxies and stars in the frame. The pitch of the sound points towards where we see the dot of light in the image. Higher pitches tell us that a star or galaxy appears further at the top in the image along the traceback line.  

The brightness of these objects in and around M78 are represented by the volume of the twinkles. Whenever we hear a particularly loud clink, the star or galaxy that Euclid observed appears particularly bright in the image. 

Underlying these jingling sounds, we can hear a steady undertone, made up of two chords which represent different regions in Messier 78. This sound intensifies as the traceback line approaches first the brightest, and later the densest regions in the nebula.  

The first two deeper crescendos in this undertone indicate two patches in the image where the most intense colour is blue/purple. These appear as two ‘cavities’ in M78, where newly forming stars carve out and illuminate the dust and gas in which they were born. 

The chords intensify a third time at a slightly higher pitch corresponding to the red-orange colours in the image, as the sound draws over the densest star-forming region of the frame. This stellar nursery is hidden by a layer of dust and gas that is so thick that it obscures almost all the light of the young stars within it.  

As the sound traces over the entire Euclid image, these different tones together form a cosmic symphony that represents the image of Messier 78, and the stars and galaxies that lie behind and within it. You can read more about this image that was first revealed to the eyes of the world earlier this year here.  

Many thanks to Klaus Nielsen (DTU Space / Maple Pools) for making the sonification in this video. If you would like to hear more sonifications and music by this artist, please visit: https://linktr.ee/maplepools 

On 9 December 2024, the Smile Platform arrived safely at Amsterdam Schiphol airport and was subsequently transported to ESA's European Space Research and Technology Centre (ESTEC) in Noordwijk, the Netherlands. It came a long way, having travelled all the way from Shanghai, China.  

This marks an important step in the Smile mission, as the spacecraft's two halves are now in the same location, ready to be joined together. Launching in around a year from now, Smile will study space weather and the interaction between the solar wind and Earth’s environment. 

The Platform, built by the Chinese Academy of Sciences (CAS), includes the propulsion and service modules responsible for powering, steering and controlling the spacecraft. The European half of the spacecraft –  the so-called Payload Module – was built by Airbus in Madrid and is already at ESTEC. It hosts three of the four science instruments of the mission, commands all four of them and downlinks all the data back to Earth. 

The Platform didn't travel alone. It was accompanied by a team of Smile engineers and managers from CAS. They will closely work together with their European counterparts from ESA and Airbus during the coming ten months to assemble the Smile spacecraft and fully test it at ESA's ESTEC Test Centre. 

After that, Smile will be shipped to Europe's Spaceport in Kourou, French Guiana. Its launch is planned for late 2025. 

All Let's Smile videos will be listed here: Let's Smile