It gave us the best map of the Milky Way. Now the Gaia spacecraft is orbiting into retirement
The Gaia spacecraft, after more than a decade of groundbreaking discoveries, officially completed its mission and was shut down on March 27 due to depleted fuel. The team on the ground had mixed emotions, with Dutch astronomer Anthony Brown reflecting on his 11 years working with the spacecraft. Despite the closure, there is still excitement about processing the remaining data.
Launched in 2013 by the European Space Agency (ESA), Gaia was stationed 1.5 million kilometers away in the second Lagrange point (L2), offering an optimal vantage point for observing the universe. Equipped with two telescopes, Gaia’s mission was to map the Milky Way, providing insights into its composition, evolution, formation, and structure. Unlike the James Webb Space Telescope, Gaia focused on detailed measurements of stars across the galaxy, exceeding expectations with its contributions.
During its extended mission, Gaia scanned the sky and recorded data on nearly two billion stars, including their position, distance, movement, chemical composition, and brightness. The spacecraft delivered surprising findings, such as possible causes of the Milky Way’s warped shape, new star clusters, and contributions to the discovery of exoplanets and black holes. Gaia also mapped millions of galaxies and tracked asteroids and comets.
Astronomers have been releasing Gaia’s data since 2016, with the final set expected no earlier than 2030. Canadian researchers, including those at Western University, have been analyzing the data and are excited about the potential discoveries. Gaia’s legacy will live on through follow-up missions that continue its work.
As Gaia bid farewell and entered retirement orbit around the sun, the team sent a final message: “Farewell to an amazing spacecraft that revolutionized 21st-century astronomy.” The spacecraft leaves behind a rich legacy of discoveries and a wealth of data for future exploration.
