A slice of the Milky Way, a barred spiral galaxy spanning some 200,000 light-years and home to our own solar system, has been captured in unparalleled detail thanks to the European Space Agency's Gaia spacecraft.
Released last April and eagerly poured over by researchers in the months since, the star map above is unique not only for its beauty –– capturing the brilliance of an estimated 1.7 billion stars –– but also in its scope. For the first time, the publicly available catalog includes the positions, distances, motions, brightness and colors of more than 1.3 billion stars. Diving deeper, it also contains the surface temperatures of 100 million stars, the radial velocity of 7 million stars, and the amount of celestial dust between us and 87 million stars. Oh –– and it also tells us the position of over 14,000 known solar system objects such as asteroids.
Even more incredible is the fact that this survey only covers about 1 percent of the 100 to 400 billion stars that are estimated to make up the Milky Way Galaxy.
Since it was launched in 2013, the Gaia spacecraft has wowed the astronomical community in a series of data releases. The first, based on a year of observations, was released in 2016 and contained the distances and motions of only 2 million stars. By comparison, this latest release constitutes 22 months of observations and involved the collaboration of about 450 scientists and software engineers.
"Gaia is astronomy at its finest," Fred Jansen, Gaia mission manager at ESA, said in a statement. "Scientists will be busy with this data for many years, and we are ready to be surprised by the avalanche of discoveries that will unlock the secrets of our Galaxy."
The secret to Gaia's ability to peer back through time and see objects nearly 1 million times fainter than the limits of the human eye comes from its billion-pixel camera. The largest such digital camera in space, it's capable of making more than 40 million observations every day.
Not surprisingly, the extraordinary breadth of the second data release is expected to fuel hundreds of scientific studies about the structure of the Milky Way.
"The sheer number of stars alone, with their positions and motions, would make Gaia's new catalogue already quite astonishing," Anthony Brown of Leiden University said. "But there is more: this unique scientific catalogue includes many other data types, with information about the properties of the stars and other celestial objects, making this release truly exceptional."
Perhaps the best way to experience this incredible color image of the Milky Way is via the ESA's 360 video below. As Brown told Space.com, the first time he saw it he "turned off all the lights, and I just sat there in the dark for a while staring at this image because it's really so beautiful."
If you really want to feel like you're touching the void, you can also check out this interactive experience of all the stars included in the Gaia map.
Like other releases, however, the best is yet to come. The third Gaia release is slated to arrive in the later half of 2020 and contain a treasure trove of data, including more precise colors on more than 2 billion stars. The spacecraft itself is expected to have enough fuel to continue until at least November 2024.
"Fundamentally, this is one of a handful of transitions in the history of mankind," professor Gerry Gilmore of the Institute of Astronomy in Cambridge said. "This is the first time that we've had a genuine three-dimensional picture of our local universe. Mankind has wanted this since ancient times…"