The Gaia spacecraft is located 1.5 million kilometers (937,000 miles) from Earth. (Representational)
Paris:
The Gaia spacecraft unveiled its latest discoveries on Monday in its quest to map the Milky Way in unprecedented detail, examining nearly two million stars and revealing mysterious “earthquakes” that sweep the fiery giants like great tsunamis.
The third set of data from the mission, which will be released to astronomers looking forward to the world at 1000 GMT, “revolutionizes our understanding of the galaxy,” the European Space Agency (ESA) said.
“It’s the knife of the Swiss Army of Astrophysics; not a single astronomer doesn’t use their data, directly or indirectly,” said Francois Mignard, a member of Gaia’s team.
Some of the new knowledge on the map is close to home, such as a catalog of more than 156,000 asteroids in our Solar System “whose orbits the instrument has calculated with unparalleled accuracy,” Mignard said.
But Gaia also sees beyond the Milky Way, discovering 2.9 million more galaxies and 1.9 million quasars: the incredibly bright hearts of galaxies fed by supermassive black holes.
The Gaia spacecraft is in an orbit strategically located 1.5 million kilometers (937,000 miles) from Earth, where it has been observing the sky since it was launched by ESA in 2013.
‘Beautiful star crucible’
“Gaia explores the sky and collects everything she sees,” said astronomer Misha Haywood of the Paris Observatory.
But it can still only detect about one percent of the stars in the Milky Way, which are about 100,000 light-years in diameter.
The probe is equipped with two telescopes and a billion-pixel camera, which captures images sharp enough to measure the diameter of a human hair at a distance of 1,000 kilometers (620 miles).
He also has a number of other instruments that allow him not only to map stars, but also to measure their motions, chemical compositions, and ages.
“It provides a global observation of the positions of anything moving in the sky, for the first time,” Haywood said, adding that before Gaia “we had a really restricted view of the galaxy.”
It also reveals the wide variety of differences between the stars.
“Our galaxy is a beautiful crucible of stars,” said Alejandra Recio-Blanco, a member of Gaia.
“This diversity is extremely important, because it tells us the history of the formation of our galaxy,” he said.
“It also clearly shows that our Sun, and we, all belong to a constantly changing system, formed by the coupling of stars and gases from different sources.”
Surprise stars tremble
The observation of “earthquakes,” massive vibrations that change the shape of distant stars, was “one of the most startling findings in the new data,” ESA said.
Gaia was not built to observe earthquakes, but it did detect the strange phenomenon in thousands of stars, including some that should have none, at least according to our current understanding of the universe.
“Gaia is opening a gold mine for ‘asterosismology’ of massive stars,” said Conny Aerts, a member of Gaia.
About 50 scientific papers were published along with the new data, and many more are expected in the coming years. Gaia’s observations have fueled thousands of studies since its first data set was published in 2016.
The second set of data from 2018 allowed astronomers to show that the Milky Way merged with another galaxy in a violent collision about 10 billion years ago.
The raw data torrent is being reviewed by a team of 450 European scientists and software engineers using six supercomputers and “human-driven algorithms” as part of the Data Processing and Analysis Consortium, Mignard said.
“Without this processing group, there is no mission,” he added, adding that Gaia produces 700 million stellar positions and 150 million photometric measurements every day.
The team took five years to deliver the latest data, which was observed from 2014 to 2017.
“We can’t wait for the astronomy community to dive into our new data to find out even more about our galaxy and its environment than we could imagine,” said Timo Prusti, a scientist at ESA’s Gaia project.
The final dataset will be released in 2030, after Gaia completes its sky exploration mission in 2025.
(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated channel.)