Astronomers were hit today (Dec. 3) with a huge wave of data from the European Space Agency’s Gaia space observatory.
Those researchers can now explore the best-yet map of the Milky Way, with detailed information on the positions, distances and motion of 1.8 billion cosmic objects, to help us better understand our place in the universe.
“Gaia data is like a tsunami rolling through astrophysics,” said Martin Barstow, head of the physics and astronomy department at the University of Leicester, who is part of Gaia’s data processing team. He was speaking at a virtual news conference held today, at which another Gaia researcher, Giorgia Busso of the Leiden Observatory in the Netherlands, also told reporters that this data has produced “a revolution” in many fields of astrophysics, from the study of galactic dynamics like stellar evolution to the study of nearby objects like asteroids in the solar system.
Photos: Gaia spacecraft to map Milky Way galaxy
Gaia launched in December 2013 to map the galaxy in unprecedented detail. The $1 billion spacecraft orbits the Lagrange-2, or L2, point, a spot about 1 million miles (1.5 million kilometers) away from Earth, where the gravitational forces between our planet and the sun are balanced and the view of the sky is unobstructed. Gaia can measure about 100,000 stars each minute, or 850 million objects each day, and can scan the whole sky about once every two months.
The latest trove of data improves upon the precision and scope of the two previous Gaia data sets, which were released in 2016 and 2018. For example, compared to the 2018 data, which included measurements for 1.7 billion objects, the 2020 data improves by a factor of two the accuracy of the data points for proper motion, or the apparent change in the position of a star as viewed from our solar system.
“It really gives us an insight into how the Milky Way lives,” Nicholas Walton, an astronomer at the University of Cambridge who is part of Gaia’s science team, said at the same science and news conference. “We’re talking about billions of stars, which really gives us the ability to probe at a meaningful level the whole population of the Milky Way, similar to what you’d want to do with studying people.”
Walton said the cosmic census would be like having trackers on every person in the U.K. to map their location and monitor their health. “If everyone’s got a tracker, we could tell you if they’re sweating or not. It’s a bit like that with the stars here: We can tell you which ones are sweating, which ones are active, which ones are dormant, which ones are going to die, which ones are going to explode.”
Data from Gaia has already been used across a wide range of applications over the past four years. The mission has helped researchers find the corpse of a galaxy that the Milky Way cannibalized 10 billion years ago, spot 20