ESA's Gaia Spacecraft Reveals Most Accurate Map Of The Milky Way

Dr. Alfredo Carpineti

Senior Staff Writer & Space Correspondent

Published

Artist's impression of Gaia with the Milky Way. ESA/ATG medialab; background image: ESO/S. Brunier

The European Space Agency (ESA) has released the first data from the Gaia mission, which has the tremendous task of building the most precise 3D map of the Milky Way.

Equipped with a billion-pixel camera, the space observatory has been measuring the position and velocity of cosmic objects since December 2013, and now ESA is ready to release the first set of data, which contains the position in the sky of one billion stars, and the position in the galaxy and the velocity of about two million of those.

“The key requirement for the mission is to understand the Milky Way galaxy better,” Timo Prusti, ESA Gaia Project Scientist, said in a press conference.

“In a way, the Milky Way is an easy target. Wherever you look, you look at the Milky Way. At the same time, it’s extremely difficult because in order to understand it completely you have to look in all directions.”

This first data showcases the capabilities of the instrument. The probe is so precise that it can gauge the size of a coin on the Moon. It can see objects 500,000 times fainter than the human eye, and it will observe every star about 70 times. This has allowed an incredibly precise map of one billion stars to be made, which we'd highly recommend you check out.

^{The map of one billion stars measured by Gaia. ESA/Gaia Collaboration}

“What is special about this map, is it contains more than one billion stars and it’s the largest map made from a single survey and it’s also the most accurate map ever made,” added Anthony Brown, from the Gaia Data Processing and Analysis Consortium, Leiden University, in the press conference.

But the precision measurements of stars is not the only objective of Gaia. The probe's accurate census of the Milky Way’s stellar population will provide new insights on how our galaxy formed. Gaia will also look for Jupiter-size exoplanets up to 500 light-years from Earth and, if all of this wasn’t enough, the probe will also be on the look-out for nearby asteroids. By the end of the mission, it is expected to have classified tens of thousands of them.

The final data release is expected to be published towards the end of 2017.