The team behind the European Space Agency’s Gaia satellite has released its first catalog of more than a billion stars in our Milky Way galaxy, but that’s just the start.
Eventually, the readings from Gaia’s all-sky survey of celestial objects will be assembled into the most detailed 3-D map ever made of our home galaxy.
“Gaia is at the forefront of astrometry, charting the sky at precisions that have never been achieved before,” Alvaro Gimenez, ESA’s director of science, said in an announcement accompanying Wednesday’s data release.
The release provides the precise position and brightness for 1.142 billion stars, which is roughly 1 percent of the Milky Way’s stellar population. About 400 million of the stars in this release are thought to have been previously uncharted.
What’s more, the distances and motions of more than 2 million stars have been measured, with more to come.
This release is based on data collected during Gaia’s first 14 months of scanning the sky, from July 2014 to September 2015. Gimenez said the release provides merely a “first impression of the extraordinary data that await us and that will revolutionize our understanding of how stars are distributed and move across our galaxy.”
Gaia was launched in 2013 and uses two telescopes to track stars and other celestial objects from the vicinity of a gravitational balance point known as Sun-Earth L2. To determine distances and motions, Gaia tracks apparent shifts in the position of objects against their cosmic background as the truck-sized spacecraft moves around the sun.
In addition to mapping stars, Gaia is also expected to detect new asteroids, exoplanets and quasars. It could even provide some new tests of Albert Einstein’s theory of general relativity.
The $830 million (€740 million) primary mapping mission is due to last until 2019.