Gaia, the European Space Agency’s formidable space observatory responsible for mapping our Milky Way, is bowing out today after 12 years of good and loyal service. The end of a beautiful scientific epic which allowed humanity to understand its cosmic neighborhood from a new angle.
This device launched in December 2013 from the Europe spaceport, in French Guiana, is indeed starting to run out of resources. It has been consuming about 12 grams of liquid nitrogen every day for more than a decade to navigate with remarkable precision, and that tank is now almost empty. Unfortunately, its reaction wheel — the device that allows spacecraft to reorient itself without using fuel — is not capable of handling this task on its own, and that means Gaia made its very last scientific observations on January 10 last.
The fact that this device has survived this long is an achievement in itself. Gaia was originally supposed to map our galaxy for 5 years. His life expectancy has more than doubled. thanks to the extremely rigorous planning of its operators, but also because it proved much more resistant than expected to micrometeorite impacts and solar storms which could have put it out of service.
A ” discovery machine » without equivalent
During these twelve years, the probe accomplished a gigantic job by constructing the largest and most accurate map of the Milky Way to date. In total, it has carried out more than 3,000 billion observations and documented 2,000 billion different stars, for a total of more than 142 TB of raw data which has fueled more than 13,000 scientific publications!
Through these contributions, Gaia has completely changed our understanding of the structure, dynamics and history of the galaxy. « Gaia has changed our perception of the Milky Way “, explains Stefan Payne-Wardenaar, head of scientific visualization at the House of German Astronomy. “ Even basic ideas have been revised, such as the rotation of the central bar of our galaxy, disk deformation, the detailed structure of spiral arms and interstellar dust near the Sun »
« The data collected by Gaia has allowed us to gain unique insights into the origin and evolution of our galaxy, the Milky Way, and has also transformed astrophysics and solar system science in ways that we do not we have not yet fully appreciated. Gaia will leave a lasting legacy for future generations », Adds astrophysicist Johannes Sahlmann in an ESA press release.
Still data in stock
And the most impressive thing is that this already tremendous progress is based only on the first years of observation. This means that there are still piles of data that have not yet been revealed or even exploited. The imminent publication of the next dataset, soberly called Gaia Data Release 4, is eagerly awaited by the scientific community.
And in the longer term, there also remains a mountain of data that specialists have not yet had time to look into. It’s a safe bet that once processed, they will once again fuel a host of remarkable discoveries. An obviously very exciting prospect for astronomers and all space lovers.
« Gaia has been THE discovery machine of this decade, and this trend is here to stay », concludes Anthony Brown, the head of the Dutch group responsible for processing the data collected by the machine.
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