Gaia satellite finally retires after 12 years of mapping the Milky Way
- Gaia has operated for 12 years, mapping the Milky Way and gathering extensive astronomical data.
- The satellite was sent into a retirement orbit after key systems were disabled as part of the shutdown process.
- This retirement marks the end of a significant mission that has greatly advanced our understanding of the galaxy.
On March 31, 2025, following a successful mission, the European Space Agency's Gaia satellite was retired and moved into a secure orbit around the Sun. Gaia has been operational for over a decade, dedicated to mapping the Milky Way galaxy in exquisite detail. Since its launch, the spacecraft has gathered extensive data on the positions, movements, and distances of various celestial objects, significantly advancing our understanding of the galaxy's structure and dynamics. It was instrumental in making revolutionary discoveries, including identifying the closest known black hole to Earth. During its operational lifespan, Gaia collected approximately 200 terabytes of data, which facilitated the monitoring of more than two billion stars through approximately three trillion observations. In addition to its primary function of mapping the galaxy, Gaia has provided vital insights into cosmic events, such as the slight wobble of the Milky Way, potentially linked to a previous collision with another galaxy. This new knowledge has critical implications for our understanding of the future trajectory of the Solar System and its eventual encounter with the Andromeda galaxy, expected to take place in 4.5 billion years. As part of the retirement process, the Gaia team has been tasked with permanently disabling the satellite's systems. This involved rewriting portions of its hard drive to embed the names of over 1,500 individuals who contributed to the mission, thus ensuring that key software components would become inoperable. Julia Fortuno, a spacecraft operations engineer, expressed a mix of emotions during this phase of the mission, reflecting on her years of dedication while overseeing the final operations of a spacecraft that has offered invaluable contributions to astrophysical research. Although Gaia is now non-operational, the data stored on its hard drives offers a time capsule of astronomical information. The hope is that in the future, should humanity possess the capability to retrieve this data, it may yield even further insights into the cosmos. Gaia's legacy lies in the vast and diverse array of scientific research it has enabled, influencing a multitude of disciplines within astronomy. The satellite's final resting position is approximately 6.2 million miles (10 million kilometers) from Earth, ensuring it presents no collision risk in the foreseeable future.