"Essentially all of astronomy benefits from this one way or another because it's very fundamental data," Anthony Brown, an astronomer at the University of Leiden in the Netherlands and chair of the Gaia Data Processing and Analysis Consortium Executive team, told Space.com. "It's a very, very broad survey mission."
Studying 1.8 billion stars is impressive, of course, but the heart of the mission's science is the statistical analysis that such large amounts of data facilitate. "I think the precise number doesn't matter so much," Brown said. "We're still only observing probably about 1% of all the stars in the Milky Way, even with this enormous number."
Although today is scientists' first chance to access the data publicly, Gaia team members have already dug through it to conduct some initial analyses. One result of that work is that scientists have measured how the solar system is accelerating in its orbit of the Milky Way, a tiny phenomenon.