Gaia Space Telescope to release most precise map of the Milky Way ever tomorrow

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In an eagerly anticipated development, astronomers have created the largest and most precise 3-D map of the Milky Way galaxy. The European Space Agency’s $1-billion Gaia mission released its newest data set in April, detailing the positions and motions of more than a billion stars.

The Gaia spacecraft, launched in 2013, scans the entire sky from its orbital parking spot above the side of Earth opposite the sun. Its unprecedented map is based on 25 separate observations of individual stars and their movements over about two years and contains a representative sample of 1 percent of the Milky Way’s orbs. The data, described in a series of papers to be published online Wednesday in Astronomy & Astrophysics, can be extrapolated to simulate the galaxy’s past and future.

Gaia released its first data set in September 2016. But because of limited observation time and reliance on prior knowledge of celestial positions, it tracked the distances and motions of only two million stars. The second data set contains similar details on 1.3 billion of them—650 times as many as the initial trove.

The telescope can accurately observe stars in the galactic center, up to 30,000 light-years away—equivalent to a person on Earth spotting a penny on the moon. “The precision of the proper motions measured by Gaia is what really makes it so revolutionary,” says Allyson Sheffield, an astrophysicist at LaGuardia Community College, who was not involved in the project.

Gaia

Gaia will create a precise three-dimensional map of astronomical objects throughout the Milky Way and map their motions, which encode the origin and subsequent evolution of the Milky Way. The spectrophotometric measurements will provide the detailed physical properties of all stars observed, characterizing their luminosity, effective temperature, gravity and elemental composition. This massive stellar census will provide the basic observational data to tackle a wide range of important questions related to the origin, structure, and evolutionary history of our galaxy.