"Gaia's extensive data releases are a unique treasure trove for astrophysical research, and influence almost all disciplines in astronomy," said Gaia Project Scientist Johannes Sahlmann in a statement.
During its 10-year operation Gaia collected data on evidence of past galactic mergers, identified new star clusters and mapped millions of quasars and galaxies.
According to the ESA Gaia also contributed to the discovery of black holes and exoplanets and tracked hundreds of thousands of asteroids and comets.
Even as Gaia was sent into retirement, the final data releases from the spacecraft's exploration will continue.
"Data release 4, planned for 2026, and the final Gaia legacy catalogs, planned for release no earlier than the end of 2030, will continue shaping our scientific understanding of the cosmos for decades to come," Sahlmann said.
The original plan for Gaia was to be in service for just five years.
Gaia Spacecraft Operator Tiago Nogueira said turning Gaia off was complicated.
"Switching off a spacecraft at the end of its mission sounds like a simple enough job," he said. "But spacecraft really don't want to be switched off."
Gaia has multiple redundant systems designed to allow it to recover from a host of potential disruptions in operation. That required a "decommissioning strategy" to disable the redundant systems.
"The final commands have been sent to Gaia. This is the last time that the spacecraft will ever hear from its team on Earth," The ESA said.
Those final commands included shutting down communications systems and Gaia's central computer.
The data archive Gaia created is so vast that it will continue to help shape astronomy for decades to come.
The decommissioning process included personal farewell messages from hundreds of team members who contributed to the mission.
"We will never forget Gaia, and Gaia will never forget us," Mission Manager Uwe Lammers said in a statement.
In June 2022 the ESA released the third set of data from Gaia, reporting that it had observed thousands of starquakes as well as what was called "stellar DNA" during a survey of the Milky Way.