The legendary spaceship Gaia maps the entire galaxy, immediately retires

The European Space Agency’s Gaia mission has completed one of its main tasks: providing a map of the Milky Way galaxy, made up of trillions of observations taken over a 10-year period.

Between July 24, 2014 and today, Gaia has taken more than three trillion observations of two billion stars and other objects in our galaxy. The result of the spacecraft’s efforts is nothing less than the largest and most accurate map of our galaxy to date. Its work is complete, and with the spacecraft running low on fuel, Gaia is now scheduled for retirement.

The amount of data brought back by Gaia has allowed scientists to produce the best reconstructed view of how our galaxy might appear to an outside observer; the edge reconstruction is above and the face view is below.

The Gaia data revealed that the Milky Way has more than two spiral arms, which are less prominent than previously thought. The brightest spot in the center of the galaxy is the galactic bulge (which looks bulgier in the top image), where resides Sagittarius A*a supermassive black hole.

The Gaia data has revealed a host of intriguing objects in our galaxy; in April 2024, scientists revealed The heaviest stellar mass black hole in the Milky Way, only 2000 light years from Earth. (In 2022, Gaia data includes the the closest known black hole to Eartha relatively small compact object only 1,600 light years away.)

In June of last year, examination of the Gaia data indicated that the interaction between the Milky Way and another galaxy may have occurred billions of years later than previously thought, shaking up theories of the evolution of our galaxy.

“Gaia has changed our impression of the Milky Way,” said Stefan Payne-Wardenaar, scientific visualizer for the Haus der Astronomie in Germany, in a press release. “Even basic ideas have been revised, such as the rotation of the central bar of our galaxy, the curvature of the disk, the detailed structure of the spiral arms, and the interstellar dust near the Sun.

Among the spacecraft’s many accomplishments: Gaia has measured the orbits of more than 150,000 asteroids with precision, and produced a three-dimensional map of more than a million quasars, the largest of its kind.

“The distant parts of the Milky Way remain educated guesses based on incomplete data,” Payne-Wardenaar added. As more Gaia data becomes available, “our view of the Milky Way will become even more precise,” he said.

The spaceship is almost out of fuel now; when its tank is completely spent, Gaia will be moved into a retreat orbit. In the coming weeks, Gaia will undergo several technology tests that will prepare the spacecraft for that endgame orbit.

But the story of the spacecraft will live on after its observational work is done. Next year, the mission is expected to make its next data release, with another data release planned for the end of the decade. Gaia has produced 500 terabytes of data so far – and that’s just from the spacecraft’s 5.5 years of observations.

“After 11 years in space and surviving micrometeorite impacts and solar storms along the way, Gaia has finished collecting scientific data,” said Johannes Sahlmann, a Gaia project scientist, at an ESA. liberation. “Now all eyes turn to preparing the next data releases.” At least 500 terabytes of data are expected to be released in next year’s data dump, which could include data on new exoplanets and binary star systems.

Gaia will be passivated– made electrically inert – on March 27, to mitigate any interference between the veteran mission and other spacecraft still at work.