The European Space Agency’s (ESA) Gaia space telescope has officially retired after an impressive eleven-year mission dedicated to mapping the Milky Way. Space Telescope Science Institute/Mikala Compton Gaia launched in December 2013. Its mission was to accurately map the location and motion of more than a billion stars in our galaxy. Scientists are already hailing the mission as “the discovery machine of the decade.” Its groundbreaking novel contributions to astrophysics are expanding our understanding of the universe at large.
In its operational years, Gaia produced the largest and most accurate three-dimensional map of the Milky Way. This incredible accomplishment delivered spectacular data to astronomers that has inspired more than 13,000 science papers. The telescope’s star-studded catalog includes a dizzying 1.8 billion stars and more than 4 million candidate galaxies. It additionally counts 150,000 asteroids, giving us a complete photo of our personal galaxy—and others past it.
A Precision Mapping Tool
Gaia carries twin telescopes that survey 360 degrees around the spacecraft. It was meant to give distances between objects in the sky with an accuracy never before achieved. Three onboard instruments painstakingly mapped dozens of star characteristics, including temperature, rotation, density and age. They painstakingly mapped out thousands of stars’ positions, velocities, colors, and chemical compositions. The treasure trove of data produced by Gaia has revolutionized astronomers’ understanding of the structure and composition of our home galaxy, the Milky Way.
In the years since, Gaia’s observations have unveiled a wonderful picture of how truly ancient much of the Milky Way is. According to recent data, at least in the galaxy’s disk, star formation began less than one billion years after the Big Bang occurred. This shocking discovery has fundamentally changed the way scientists think about galaxy evolution and star formation processes.
“Gaia has changed our impression of the Milky Way,” – Stefan Payne-Wardenaar, a scientific visualiser at Heidelberg University in Germany.
On top of this, Gaia serendipitously recorded thousands of these starquakes, offering one-of-a-kind glimpses into stellar interiors. This work identified high-velocity stars. Whether these stars are escaping the Milky Way or racing towards it, this research sheds light on galactic dynamics.
Insights into Galactic Structure
Gaia’s extensive data releases have not only enhanced knowledge about individual stars but have contributed to broader understandings of the Milky Way’s overall structure. The telescope’s mapping efforts have helped solve long-standing mysteries regarding the galaxy’s warped and wobbling disk. Gaia’s data has been very important for estimating the shape of the dark matter halo. The project has allowed scientists to estimate the mass around the Milky Way.
One of the key findings from Gaia’s catalog has been its ability to clock the expansion rate of the universe. This knowledge becomes essential for astronomers as they explore the evolution of our cosmos and the dynamic processes that shape its course.
“Gaia’s extensive data releases are a unique treasure trove for astrophysical research, and influence almost all disciplines in astronomy,” – Johannes Sahlmann, a physicist at the European Space Astronomy Centre in Spain and a project scientist for the Gaia mission.
