The European Space Agency's (ESA) Gaia spacecraft concluded its sky-scanning mission after mapping the Milky Way for more than 10 years. On January 15, Gaia completed its last observations, marking the end of its active mission.
"Today marks the end of science observations, and we are celebrating this incredible mission that has exceeded all our expectations, lasting for almost twice its originally foreseen lifetime," said Carole Mundell, ESA Director of Science, according to Scientias.
Gaia was launched on December 19, 2013, and began scanning the stars in July 2014. It mapped over two billion stars, revolutionizing our knowledge of the Milky Way. Gaia made over three trillion observations of nearly two billion stars and other cosmic objects.
After completing scientific observations, a short period of technology testing began. During this phase, Gaia conducted final experiments as it entered a phase of passive flight. According to ANSA, at the end of March 2024 Gaia be sent to an orbit around the Sun to avoid collisions or interfering signals from other space probes.
ESA stopped operating Gaia because it ran out of cold gas propellant used for maneuvering in space, consuming approximately ten grams of cold gas per day to maintain its rotation and scanning of the sky.
Gaia mapped the precise orbits of more than 150,000 asteroids and helped to better understand how stars form in nearby star clusters. "Gaia observed things for which it was not designed, which has allowed astronomers to study star clusters as a whole," noted ANSA.
"The data from Gaia have overturned even the most fundamental concepts about the center of the galaxy and the spiral arms," said ESA Director General Josef Aschbacher, according to Die Zeit. The data forced scientists to abandon old ideas about the Milky Way and replace them with compelling new ones.
"Gaia was the discovery machine of the decade," said Anthony Brown from Leiden University, chair of the consortium for processing the probe data, adding that it "will continue to have an impact for a long time."
Despite the mission ending, some discoveries made by Gaia may still be forthcoming, as the collected data continues to be evaluated, constituting a "backbone of astronomical research," according to Focus Online. Gaia's data led to dozens of new important discoveries and are the basis of over 13,000 scientific publications.
Future datasets from Gaia are expected to be published next year and towards the end of the decade, including the fifth and final major data release encompassing 10.5 years of mission data, as reported by Scientias.
In the coming weeks, technical tests were scheduled for Gaia, which were necessary before the spacecraft could leave its current position at Lagrange Point 2, approximately 1.5 million kilometers from Earth, according to Het Nieuwsblad.
This article was written in collaboration with generative AI company Alchemiq