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European Space Agency releases preliminary map of 1 billion stars

ESA

The European Space Agency just released an intricate star map cataloging the precise positions of more than 1.1 billion stars in the Milky Way Galaxy. So far, it’s the largest chart of celestial objects ever made, and it’s all thanks to data gathered by ESA’s Gaia spacecraft — a space observatory located about 1 million miles above Earth.

Launched in 2013, Gaia has been scanning the sky for the past two years in hopes of creating the most detailed 3D map ever of the stars in our galaxy. Such a star chart will help scientists better understand the structure of our galaxy, as well as how it formed and evolved over time.

A star chart will help scientists better understand the structure of our galaxy

Today’s data dump from ESA is just a teaser for what’s to come. Gaia will eventually help astronomers pinpoint exactly how far away all these stars are, and how they move throughout the galaxy. ESA offered a glimpse of this data today by also releasing the distances and movements of 2 million stars. The information was gathered by Gaia between June 2014 and September 2015.

"Today’s release gives us 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," Alvaro Giménez, ESA’s director of science, said in a statement.

ESA's Gaia space observatory. (ESA)

To spy on stars, Gaia uses two telescopes and 10 mirrors, which direct starlight to the spacecraft’s three science instruments. These instruments use the light to determine star position and movement, as well as measure the stars’ compositions, temperatures, and brightness.

After about five years of operation, Gaia will help astronomers know the movements and distances of more than 1 billion stars in our galaxy. That may seem like a lot, but such a collection will only represent about 1 percent of all the stars in the Milky Way. Still, it will be the most comprehensive star map ever created.