ESA Maps More Than a Billion Stars in Our Galaxy

The Gaia space probe, launched in 2013, has mapped more than a billion stars in the Milky Way, vastly expanding the inventory of known stars in our galaxy, the European Space Agency said Wednesday.

ESA Maps More Than a Billion Stars in Our Galaxy

Released to eagerly waiting astronomers around the world, the initial catalogue of 1.15 billion stars is “both the largest and the most accurate full-sky map ever produced,” said French astronomer Francois Mignard, a member of the 450-strong Gaia consortium.

In a web-cast press conference at the ESA Astronomy Centre in Madrid, scientists unveiled a stunning map of the Milky Way, including stars up to half a million times feinter than those that can be seen with the naked eye.

The images were captured by Gaia’s twin telescopes — scanning the heavens over and over — and a billion-pixel camera, the largest ever put into space.

The resolution is sharp enough to gauge the diameter of a human hair at a distance of 1,000 kilometres (620 miles), said Anthony Brown, head of the Gaia data processing and analysis team.

Gaia maps the position of the Milky Way’s stars in a couple of ways.

Not only does it pinpoint their location, the probe — by scanning each star multiple times — can plot their movement as well.

The data release today includes both kinds of data for some two million stars.

But over the course of Gaia’s five-year mission, that catalogue is set to expand 500-fold.

Orbiting the Sun 1.5 million kilometres (nearly a million miles) beyond Earth’s orbit, the European probe started collected data in July 2014.

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