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The 2025 EarthSky lunar calendar available now. Moon phases every day on a poster-sized calendar. Get yours today!<\/p>\n
Today, Wednesday, January 15, 2025, the Gaia spacecraft will take its final measurements of our Milky Way galaxy. Gaia \u2013 a mission of the European Space Agency \u2013 launched in 2013 and has been expanding our view of our home galaxy since its arrival at Lagrange Point 2 in 2014. Lagrangian points are locations in space where gravitational forces and the orbital motion of a body balance each other. The goal of Gaia was to make a precise 3D map of the Milky Way. Over the past decade, it has tracked and measured the motions, luminosity, temperature and composition of nearly 2 billion objects.<\/p>\n
But ESA said that the cold gas propellant that keeps the mission working is running out. While Gaia will cease taking measurements of our galaxy, the data releases from the project will continue for some years yet. Gaia\u2019s first three data releases came in 2016, 2018 and 2022. The 4th data release should be ready in 2026. And the 5th and final data release covering all 10 1\/2 years of data will be around the end of the decade. The massive amounts of data take quite a long time to process!<\/p>\n
Gaia will not float out at the Lagrange Point 2 forever. Engineers have planned to remove Gaia from its current orbit. ESA said: <\/p>\n
\nGaia will be inserted into an orbit that makes sure it does not come too close to the Earth-moon system in the near future. The Gaia spacecraft will be fully passivated when it moves to its final orbit, to avoid any harm or interference with other spacecraft.<\/p>\n<\/blockquote>\n
After January 15, Gaia will undergo some testing, which will make it temporarily brighter in the sky. Normally, Gaia has been a very faint magnitude 21 as it orbits the sun out at Lagrange Point 2. But for while it will brighten to magnitude 15. That\u2019s still incredibly faint for the casual observer. You\u2019d need quite a large telescope to track it down. But if that\u2019s your kind of fun, here\u2019s information on how to find it.<\/p>\n
What has Gaia already shown us?<\/h3>\n
Astronomers have used the data from Gaia to make all sorts of new discoveries about our galaxy. Here are some highlights:<\/p>\n
Also, Gaia has made discoveries outside of the Milky Way, including spotting stars flying between galaxies and the discovery of an enormous ghost galaxy on the Milky Way\u2019s outskirts. <\/p>\n
Watch what Phil Plait had to say about Gaia during a recent livestream with Deborah Byrd.<\/p>\n
Bottom line: ESA\u2019s Gaia spacecraft has spent more than a decade measuring nearly 2 billion objects in our Milky Way galaxy. Its measurements end on January 15, 2025.<\/p>\n
Via ESA<\/p>\n
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