Ten years ago, on 19 December 2013, our billion star-mapping satellite Gaia launched.
Since then, Gaia has been scanning the sky and gathering an enormous amount of data on the positions and motions of 1.8 billion stars, enabling discoveries about the history of our galaxy.
Gaia is creating an extraordinarily precise three-dimensional map of more than a billion stars throughout our Milky Way galaxy and beyond, mapping their motions, luminosity, temperature and composition.
This huge stellar census will provide the data needed to tackle an enormous range of important questions related to the origin, structure and evolutionary history of our galaxy.
Gaia’s catalogue is ever-growing containing data on stars and other cosmic objects such as galaxies, exoplanets, and binary stars. Here’s to more discoveries!
One of the surprising discoveries coming out of Gaia data release 3, is that Gaia is able to detect starquakes – tiny motions on the surface of a star – that change the shapes of stars, something the observatory was not originally built for.
Previously, Gaia already found radial oscillations that cause stars to swell and shrink periodically, while keeping their spherical shape. But Gaia has now also spotted other vibrations that are more like large-scale tsunamis. These nonradial oscillations change the global shape of a star and are therefore harder to detect.
Nonradial oscillation modes cause a star’s surface to move while it rotates, as shown in the animation. Dark patches are slightly cooler than bright patches, giving rise to periodic changes in the brightness of the star. The frequency of the rotating and pulsating stars was increased 8.6 million times to shift them into the audible range of humans.
Credit: ESA/Gaia/DPAC, CC BY-SA 3.0 IGO. Acknowledgement: Animation and sonification were created by: Dr. Joey Mombarg, KU Leuven, Belgium. Based on information from Gaia Data Release 3: Pulsations in main-sequence OBAF stars as observed by Gaia by the Gaia Collaboration, De Ridder et al., 2022, submitted to A&A. Van Reeth et al. 2015, ApJS 218, id.2, 32 pp. Mombarg et al. 2021, A&A 650, id.A58, 23 pp.
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We are Europe’s gateway to space. Our mission is to shape the development of Europe’s space capability and ensure that investment in space continues to deliver benefits to the citizens of Europe and the world. Check out https://www.esa.int/ to get up to speed on everything space related.
Since its launch in 2013 ESA’s Gaia observatory has been mapping our galaxy from Lagrange point 2, creating the most accurate and complete multi-dimensional map of the Milky Way. By now two full sets of data have been released, the first set in 2016 and a second one in 2018. These data releases contained stellar positions, distances, motions across the sky, and colour information, among others. Now on 13 June 2022 a third and new full data set will be released. This data release will contain even more and improved information about almost 2 billion stars, Solar System objects and extragalactic sources. It also includes radial velocities for 33 million stars, a five-time increase compared to data release 2. Another novelty in this data set is the largest catalogue yet of binary stars in the Milky Way, which is crucial to understand stellar evolution.
We are Europe’s gateway to space. Our mission is to shape the development of Europe’s space capability and ensure that investment in space continues to deliver benefits to the citizens of Europe and the world. Check out https://www.esa.int/ to get up to speed on everything space related.
With a simple Google Cardboard-style virtual reality (VR) viewer, you can experience how it feels to be a spacecraft hurtling past Earth. This 360-degree VR simulation of a flyby manoeuvre performed by ESA’s Mercury-bound BepiColombo spacecraft takes you on a trip past Earth at the distance of only 12 700 km, closer than the orbit of Europe’s navigational satellites Galileo.
The simulation displays the field of view of two of BepiColombo’s science instruments (MERTIS and PHEBUS) and two of its three MCAM selfie cameras during the gravity-assist flyby at Earth on 10 April 2020.
The simulation was created using the SPICE software developed by NASA’s Jet Propulsion Laboratory and data generated by the European Space and Astronomy Centre (ESAC)in Spain.
BepiColombo, a joint mission of ESA and the Japan Aerospace Exploration Agency (JAXA), is on a seven-year cruise to Mercury, the smallest and innermost planet of the Solar System. Launched in October 2018, BepiColombo follows an intricate trajectory that involves nine gravity-assist flyby manoeuvres. In addition to the flyby at Earth, BepiColombo will perform two flybys at Venus and six at Mercury, its target planet. The manoeuvres slow down the spacecraft as it needs to constantly brake against the gravitational pull of the Sun in order to be able to enter the correct orbit around Mercury in 2025, ahead of commencing science operations in early 2026.
Credit: ESA SPICE Service/RHEA Group.
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We are Europe’s gateway to space. Our mission is to shape the development of Europe’s space capability and ensure that investment in space continues to deliver benefits to the citizens of Europe and the world. Check out http://www.esa.int/ESA to get up to speed on everything space related.
Since arriving at Mars in October 2016, the ExoMars Trace Gas Orbiter has been aerobraking its way into a close orbit of the Red Planet by using the top of the atmosphere to create drag and slow down. It is almost in the right orbit to begin observations – only a few hundred kilometres to go! With aerobraking complete, additional manoeuvres will bring the craft into a near-circular two-hour orbit, about 400 km above the planet, by the end of April. The mission’s main goal is to take a detailed inventory of the atmosphere, sniffing out gases like methane, which may be an indicator of active geological or biological activity. The camera will help to identify surface features that may be related to gas emissions. The spacecraft will also look for water-ice hidden below the surface, which could influence the choice of landing sites for future exploration. It will also relay large volumes of science data from NASA’s rovers on the surface back to Earth and from the ESA–Roscosmos ExoMars rover, which is planned for launch in 2020.
This animation shows the proposed trajectory of ESA’s Jupiter Icy Moons Explore (Juice) mission to Jupiter.
Based on a launch in June 2022, the spacecraft will make a series of gravity-assist flybys at Earth (May 2023, September 2024 and November 2026), Venus (October 2023) and Mars (February 2025) before arriving in the Jupiter system in October 2029.
The animation ends at the Jupiter orbit insertion point, but the planned 3.5 year mission will see Juice not only orbit Jupiter, but also make dedicated flybys of the moons Europa, Callisto and Ganymede, before orbiting the largest moon, Ganymede.
Animation visualising Rosetta’s trajectory around Comet 67P/Churyumov–Gerasimenko, from arrival to mission end.
The animation begins on 31 July 2014, during Rosetta’s final approach to the comet after its ten-year journey through space. The spacecraft arrived at a distance of 100 km on 6 August, from where it gradually approached the comet and entered initial mapping orbits that were needed to select a landing site for Philae. These observations also enabled the first comet science of the mission.The manoeuvres in the lead up to, during and after Philae’s release on 12 November are seen, before Rosetta settled into longer-term science orbits.
In February and March 2015 the spacecraft made several flybys. One of the closest triggered a ‘safe mode’ that forced it to retreat temporarily until it was safe to draw gradually closer again.
The comet’s increased activity in the lead up to and after perihelion in August 2015 meant that Rosetta remained well beyond 100 km for several months.In June 2015, contact was restored with Philae again – albeit temporary, with no permanent link able to be maintained, despite a series of dedicated trajectories flown by Rosetta for several weeks.
Following the closest approach to the Sun, Rosetta made a dayside far excursion some 1500 km from the comet, before re-approaching to closer orbits again, enabled by the reduction in the comet’s activity.
In March–April 2016 Rosetta went on another far excursion, this time on the night side, followed by a close flyby and orbits dedicated to a range of science observations.
In early August the spacecraft started flying elliptical orbits that brought it progressively closer to the comet. On 24 September Rosetta left its close, flyover orbits and switched into the start of a 16 x 23 km orbit that was used to prepare and line up for the final descent.
On the evening of 29 September Rosetta manoeuvred onto a collision course with the comet, beginning the final, slow descent from an altitude of 19 km. It collected scientific data throughout the descent and gently struck the surface at 10:39 GMT on 30 September in the Ma’at region on the comet’s ‘head’, concluding the mission.
The trajectory shown in this animation is created from real data, but the comet rotation is not. Distances are given with respect to the comet centre (except for the zero at the end to indicate completion), but may not necessarily follow the exact comet distance because of natural deviations from the comet’s gravity and outgassing. An arrow indicates the direction to the Sun as the camera viewpoint changes during the animation.
Animation of Rosetta’s trajectory over the last two months of its mission at Comet 67P/Churyumov–Gerasimenko.
The animation begins in early August, when the spacecraft started flying elliptical orbits that brought it progressively closer to the comet at its closest approach.
On 24 September 2016, Rosetta will leave its current close, flyover orbits and transfer into the start of a 16 x 23 km orbit that will be used to prepare and line up for the final descent.
On the evening of 29 September (20:50 GMT) Rosetta will manoeuvre onto a collision course with the comet, beginning the descent from an altitude of 19 km. The spacecraft will fall freely, without further manoeuvres, collecting scientific data during the descent.
The trajectory shown here was created from real data provided over the last month, but may not necessarily follow the exact comet distance because of natural deviations from the comet’s gravity and outgassing.
Animation of Rosetta’s final trajectory in the last 10 days of its mission at Comet 67P/Churyumov–Gerasimenko.
On 24 September 2016, Rosetta will leave a close flyover orbit and transfer into the start of a 16 x 23 km orbit that will be used to prepare and line up for the final descent. In the evening of 29 September (20:50 GMT) Rosetta will manoeuvre onto a collision course with the comet, beginning the descent from an altitude of 19 km. The spacecraft will fall freely, without further manoeuvres, collecting scientific data during the descent.
The trajectory shown in this animation is created from real data provided in the last month, but may not necessarily follow the exact distance/time details because of natural deviations in the trajectory associated with the comet’s gravity and outgassing.
This video, part of a new series of ESA teaching resources called ‘Teach with space’, shows an experiment that can be performed by teachers in the classroom to demonstrate the concept of a barycentre, or centre of mass, and how objects in orbit around each other move.
Animation showing Rosetta’s orbit in the lead up to, during and after lander separation.
The animation begins on 1 October 2014, when Rosetta is orbiting about 19 km from Comet 67P/Churyumov–Gerasimenko (all distances refer to the comet’s centre). The animation shows the transition to the close 10 km orbit by mid-October, and then the steps taken to move onto the pre-separation trajectory.
On the day of landing, 12 November, Rosetta makes a further manoeuvre 2–3 hours before separation to move to 22.5 km from the comet centre to deploy the lander, Philae. While Philae descends to the surface over a period of seven hours, Rosetta makes another manoeuvre to maintain visibility with the lander. A series of ‘relay phase’ manoeuvres then move Rosetta out to a distance of about 50 km, before moving first to a 30 km orbit and later to an orbit at about 20 km by early December.
The speed of the animation slows during the separation and lander phase to better highlight these events. The comet shape and rate of rotation is real – the comet rotates with a period of about 12.4 hours.
