Map Of One Billion Stars Could Revolutionize Our Understanding of Space

A newly-released data set from the European Space Agency’s Gaia mission contains high-precision measurements about the distances and movements of around 1.4 billion stars, providing unparalleled information about our galaxy and beyond.

This is the second set of data we’ve received from Gaia, a spacecraft orbiting the Sun. The vehicle launched in 2013 and released its first batch of measurements three years later. The new data set goes far beyond the 2016 catalogue by mapping a dizzying number of stars in astonishing detail—and even measuring the brightness, color, and surface temperatures of some stars.

The European spacecraft Gaia just unveiled this portrait of the Milky Way galaxy.

Jackie Faherty, an astronomer at the American Museum of Natural History, says the importance of this map cannot be overestimated. “Gaia is revolutionary. There’s not a single aspect of what you study that can’t be touched by this mission—anything from the closest-by things that I study to the farthest things in the universe.”

To put things in perspective, Faherty previously spent three years measuring the distances to 75 celestial objects called brown dwarf stars. “These measurements are hard to make,” she explains.

Yesterday, American astronomers gathered in the wee hours of the morning in anticipation of the European Space Agency’s press release and the subsequent data drop. Faherty was watching at the Flatiron Institute in New York City with her colleagues. The room was overflowing with astronomers, and as soon as the data was online, everyone rushed to hackathons where they excitedly began digging into the science.

Scientists will need years and years to analyze all the data. And this is only the beginning—a third release in 2020 will provide even more data, this time about planets outside our solar system.

Gaia will be the first to use a novel technique called astrometric detection to look for small wobbles in stars’ positions. Since planets exert a gravitational pull on the stars that they orbit, these wobbles can provide valuable information about planets in the far corners of our universe.

The 2020 data release will complement NASA’s Kepler mission and its successor TESS, which finds planets using transit photometry and detects the subtle dimming of stars as planets pass between Earth and these stars. The hope is that Gaia will verify NASA’s findings and further our search for new planets and life beyond Earth.

The best part is that this bounty of data isn’t just for astronomers. Anyone with an internet connection can download Gaia’s measurements from the project website and figure out where their favorite space object is.

“To me, that’s the most important thing that you could get across. Let people know that it’s their data, as much as it’s our data,” Faherty said.