Gaia’s Map of 1.3 Billion Stars Makes for a Milky Way in a Bottle
https://www.nytimes.com/2018/05/01/science/gaia-map-milky-way.html
Source: By Dennis Overbye, The New York Times.
Excerpt: ...astronomers in Europe released a three-dimensional map of the Milky Way. It is the most detailed survey ever produced of our home galaxy. It contains the vital statistics of some 1.3 billion stars — about one percent of the entire cosmic panoply of which Earth and the sun are part. Not to mention measurements of almost half a million quasars, asteroids and other flecks in the night. Analyzing all these motions and distances, astronomers say, could provide clues to the nature of dark matter. The gravity of that mysterious substance is said to pervade space and sculpt the arrangements of visible matter. Gaia’s data could also reveal information about the history of other forces and influences on our neighborhood in the void. And it could lead to a more precise measurement of a historically troublesome parameter called the Hubble constant, which describes how fast the universe is expanding. The map is the latest result from the European Space Agency’s Gaia mission, which was launched into an orbit around the sun in December 2013. ...Gaia’s cameras find the distances to stars by triangulation, measuring how their images shift against background stars and quasars as the spacecraft swings from one side of its orbit to the other — a baseline of about 186 million miles. A preliminary data release, containing information on 2 million stars, was published in 2016....
Source: By Dennis Overbye, The New York Times.
Excerpt: ...astronomers in Europe released a three-dimensional map of the Milky Way. It is the most detailed survey ever produced of our home galaxy. It contains the vital statistics of some 1.3 billion stars — about one percent of the entire cosmic panoply of which Earth and the sun are part. Not to mention measurements of almost half a million quasars, asteroids and other flecks in the night. Analyzing all these motions and distances, astronomers say, could provide clues to the nature of dark matter. The gravity of that mysterious substance is said to pervade space and sculpt the arrangements of visible matter. Gaia’s data could also reveal information about the history of other forces and influences on our neighborhood in the void. And it could lead to a more precise measurement of a historically troublesome parameter called the Hubble constant, which describes how fast the universe is expanding. The map is the latest result from the European Space Agency’s Gaia mission, which was launched into an orbit around the sun in December 2013. ...Gaia’s cameras find the distances to stars by triangulation, measuring how their images shift against background stars and quasars as the spacecraft swings from one side of its orbit to the other — a baseline of about 186 million miles. A preliminary data release, containing information on 2 million stars, was published in 2016....