The European Space Agency (ESA) released a new map of the Milky Way on Wednesday with precise measurements of nearly 1.7 billion stars. The data include measurements of the stars’ brightness, motion, distance and colour that were collected between July 2014 and May 2016 by the space agency’s Gaia probe.
Launched in 2013, the Gaia spacecraft orbits our sun around a million miles away from Earth. The spacecraft’s highly precise measurements have allowed scientists to create the most accurate map of our galaxy to date. The long-awaited release has provided astronomers with vast amounts of new data and opened up many research possibilities.
“This 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.”
“We’re really talking about an immense change to our knowledge about the Milky Way,” Hogg added.
In a press release, ESA said that it expects “major discoveries” to come once scientists have the chance to explore the new data, which it presented at the ILA Berlin Air and Space Show in Germany.
“The new Gaia data are so powerful that exciting results are just jumping at us,” said Antonella Vallenari, one the project’s lead scientists from the Astronomical Observatory of Padua, Italy.
“For example, we have built the most detailed Hertzsprung-Russell diagram of stars ever made on the full sky and we can already spot some interesting trends,” Vallenari added. “It feels like we are inaugurating a new era of Galactic archaeology.”
Vallenari said the observations support a theory that the Milky Way was formed after being struck by material from another galaxy, according to AP. She said this impact resulted in “ripples” of stars moving in surprising ways, unlike the largely uniform motion of other stars in our galaxy.
The new data release follows the 2016 publication of a smaller collection of measurements covering two million stars. ESA plans to release additional data in the coming years, with the final Gaia catalogue expected sometime in the 2020s. Scientists said they are working on improvements for the third release.
“We hope to get into the centre of the galaxy by the time of our final data release. This would cover a distance of several tens of thousands of light years,” Gaia science operations manager Uwe Lammers told DW.
Although the number of stars surveyed is not expected to increase significantly, scientists expect the quality of the data to improve substantially compared to today. Science Magazine reports that the team wants to improve the way stray light affects Gaia’s detector, as well as re-examine the brightest stars using a “special short-exposure observing mode” so they do not saturate the detector.