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.
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The third set of data from the mission, which was released to astronomers looking forward to the world at 10:00 GMT, “revolutionizes our understanding of the galaxy,” the European Space Agency (ESA) said. .
ESA Director General Josef Aschbacher told a news conference that it was “a fantastic day for astronomy” because the data “will open the door to new science, to new discoveries in our universe, of our Milky Way. “
Some of the new knowledge on the map came home, such as a catalog of more than 156,000 asteroids in our Solar System “whose orbits the instrument has calculated with unparalleled accuracy,” François Mignard, a member of AFP, told AFP. the Gaia team.
But Gaia also sees beyond the Milky Way, observing 2.9 million more galaxies and 1.9 million quasars, the surprisingly 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.
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The observation of earthquakes, massive vibrations that change the shape of distant stars, was “one of the most surprising discoveries 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.
“We have a fantastic new gold mine to do the asterosismology of hundreds of thousands of stars in our Milky Way galaxy,” said Conny Aerts, a member of the Gaia team.
Gaia has studied more than 1.8 billion stars, but this represents only 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 single strand of human hair 1,000 kilometers (620 miles) away.
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.
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Incredibly accurate data “allows us to look at more than 10 billion years in the past history of our own Milky Way,” said Anthony Brown, president of the Data Processing and Analysis Consortium, which examined the vast amount of data.
Gaia’s results are already “far beyond what we expected” at the moment, Mignard said.
They show that our galaxy is not moving through the universe as intended, but is “turbulent” and “restless,” he said.
“He’s had a lot of accidents in his life and he still has them,” as he interacts with other galaxies, he added. “It may never be in a steady state.”
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“Our galaxy is really a living entity, where objects are born, where they die,” Aerts said.
“Surrounding galaxies are constantly interacting with our galaxy and sometimes also fall into it.”
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 dataset 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.
It took the team five years to deliver the latest data, which was observed from 2014 to 2017.
The final dataset will be released in 2030, after Gaia completes its sky exploration mission in 2025.
Monday’s launch only confirmed two new exoplanets and 200 more potential candidates, but much more is expected in the future.
“In principle, Gaia, especially when it lasts 10 full years, should be able to detect tens of thousands of exoplanets up to the mass of Jupiter,” Brown said.