Where is home? It’s partly a question of scale. The smallest version of the answer might be a bedroom, then an apartment or a building. Slightly larger: a city, state, or country, and larger still, a galaxy. All of us Earthlings live inside the Milky Way, and a new trove of data could tell us much more about our shared home turf and our galactic neighbors.
Since 2013, the European Space Agency’s Gaia satellite has been probing our galaxy from an orbit around the sun, roughly a million miles from Earth. To produce a new set of images, released this week, 450 scientists and data whizzes analyzed observations that Gaia collected between July 2014 and May 2016. The images include the map above, which the ESA describes as an “all-sky view” of the Milky Way and nearby galaxies.
Of course, “nearby” is relative: Some of these stars are as many as 8,000 light years from Earth. In all, Gaia captured the position and brightness of 1.7 billion twinklers, still just a sliver—roughly one percent—of the billions bedazzling our galaxy. It also collected data about the surface temperature and dust around millions of others.
The release is “a very big deal,” David Hogg, an astrophysicist at New York University and the Flatiron Institute, told NPR. “I’ve been working on trying to understand the Milky Way and the formation of the Milky Way for a large fraction of my scientific career, and the amount of information this is revealing in some sense is thousands or even hundreds of thousands of times larger than any amount of information we’ve had previously,” he said. “We’re really talking about an immense change to our knowledge about the Milky Way.”
Even if these observations only consider a cranny of the universe, it’s an immense amount of raw data; sifting through it will be an ongoing project. Meanwhile, it’s freely available online—anyone can probe it for problems, questions, and answers that reveal even more about the place we all call home.