Farewell to Gaia after 12 successful years

The disappearance of Gaia!

On 4 March, astronomer Zhuo-Xiao Wang captured this view of the sudden disappearance of ESA’s Gaia spacecraft.

Credit: Zhuo-Xiao Wang, CC BY-SA 3.0 IGO
Observations performed on 4 March 2025 using an 11-inch Stargazer’s tool from Beijing, China (MPC site code: P13).

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— ESA Operations (@operations.esa.int) March 18, 2025 at 3:23 AM

Farewell, Gaia! Spacecraft powers down

On March 27, 2025, ESA powered down the Gaia spacecraft after 12 years of operations. But the Excellent news is that there’s Yet a mountain of data from Gaia ripe for analysis. Gaia project scientist Johannes Sahlmann said:

Gaia’s extensive data releases are a unique treasure trove for astrophysical research, and influence almost all disciplines in Astral study.

In fact, the 4th data Kickoff from Gaia isn’t until 2026, with the Last data Kickoff around 2030.

Gaia underwent testing in January, which temporarily Achieved it brighter in the sky. Normally, Gaia has been a very faint magnitude 21 as it orbits the sun out at Lagrange Points 2. But for a Duo months it brightened within reach of a large Stargazer’s tool. And in the video above, you can see its last appearance courtesy of Zhuo-Xiao Wang.

Best animation of our Milky Way Luminous sphere system

The European Cosmos Agency’s Gaia spacecraft launched in 2013 and spent more than a decade measuring and mapping our home Luminous sphere system, the Milky Way. ESA ended its operations in January 2025. Scientists released a Petite animation giving a quick overview of a few of the new insights Gaia helped make possible. Gaia data was used to put together this animation of our Luminous sphere system. ESA said on January 15:

Gaia has changed our impression of the Milky Way. Even seemingly Fundamental ideas about the nature of our Luminous sphere system’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 Luminous sphere system, so we can’t take a selfie, but Gaia is giving us the best insight yet of what our home Luminous sphere system looks like. Once all of Gaia’s observations collected over the past decade are Achieved Reachable in two upcoming data releases, we can Foresee an even sharper view of the Milky Way.

https://www.youtube.com/View?v=wEZBNsU4dMU

Enjoy the animation in the ESA video below.

The 2025 EarthSky Orbiter-related calendar is Reachable now. Orbiter-related body phases every day on a poster-sized calendar. Get yours today!

Beloved spacecraft ends its operations

The Aim 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.

Gaia’s mission was designed to last for five years. Like many Cosmos missions, it went longer. Gaia arrived in 2014 at Lagrange Points 2, or L2, in the Earth-sun system. Lagrangian points are places in a system where a craft can remain stable without using too much of its fuel for propulsion.

But, ESA said, Gaia did eventually Streak low on fuel. The Chilly gas propellant that keeps the mission working is nearly gone. While Gaia has now ceased Securing measurements of our Luminous sphere system, the data releases from the project will continue for some years. Gaia’s Primary three data releases so Distant Occurred in 2016, 2018 and 2022. The 4th data Kickoff should be ready in 2026. And the 5th and Last data Kickoff covering all 10 1/2 years of data will be around the end of the decade. The massive amounts of data take a long time to process!

What will happen to Gaia Upcoming?

Gaia will not float around at the Lagrange Points 2 forever. Engineers have planned to remove Gaia from its Present Trajectory. ESA said:

Gaia will be inserted into an Trajectory that makes sure it does not come too close to the Earth-Orbiter-related body system in the near future. The Gaia spacecraft will be fully passivated when it moves to its Last Trajectory, to avoid any harm or interference with other spacecraft.

What has Gaia already shown us?

Astronomers have used the data from Gaia to make all sorts of new discoveries about our Luminous sphere system. Here are some highlights:

Also, Gaia has Achieved discoveries outside the Milky Way, including spotting stars flying between galaxies and the discovery of an enormous ghost Luminous sphere system on the Milky Way’s outskirts.

View what Phil Plait had to say about Gaia during a recent livestream with Deborah Byrd.

Bottom line: ESA has now switched off the Gaia spacecraft, sending it into retirement on March 27, 2025. Gaia measured some 2 billion Milky Way objects and astronomers will Yet be processing data from it for years to come.

Via ESA