Astronomers first saw what would happen to the Earth as the sun ran out of hydrogen by observing an elderly star in the constellation of Poop, according to an article published in the journal Astronomy & Astrophysics.
“In five billion years, the Sun will turn into a red giant and swell to a size hundreds of times greater than its current dimensions. In addition, it will begin to eject gigantic amounts of matter due to the intensification and acceleration of the solar wind. Mercury and Venus would be destroyed, but the fate of the Earth remained unknown. Life on it, of course, will perish, but we did not know if the Earth would survive in principle,”said Leen Decin from the Catholic University of Leuven (Belgium).
Decin and her colleagues found answers to all these questions by tracking the closest analogue of the "dying sun" - the red giant L2 in the constellation of Poppa. The star is located relatively close to us, just 200 light years from the solar system. This allowed astronomers to study in detail the structure of her "mantle", woven from matter ejected by the solar wind, using the ALMA telescope in Chile.
The age of L2, judging by its spectrum and environment, is about 10 billion years, and after 500 million years, a short time by the standards of space, it will end its existence, turning into a white dwarf. According to Decin, about five billion years ago, this star was actually a "double" of our Sun, having similar dimensions and physical characteristics.
Much to the surprise of scientists, images from ALMA showed that a planet orbiting a dying star is orbiting at a distance approximately equal to the distance between the Sun and Mars, about 300 million kilometers, making one revolution around the star in five years.
Scientists discovered the planet thanks to a kind of empty "donut" in a ring of dust and gas that surrounds a dying star. The planet, revolving around the red giant, "ate" a relatively empty zone inside this ring, which is clearly visible in microwave images obtained by the Chilean radio telescope.
The discovered planet, of course, is not analogous to either Earth or Mars. This is a large gas giant, whose mass, according to the calculations of the authors of the article, is about 12 times higher than that of Jupiter. Life on such a planet could not exist even in conditions similar to those that exist today in the orbits of the Earth and Mars.
The very existence of the planet in the red giant suggests that they can survive in such conditions, existing for hundreds of millions or even billions of years after the "swelling" of the star. What would have happened to the Earth is not yet known, since our planet, judging by observations from L2, would be at the very edge between the "safe" zone, where the planets should survive, and the "zone of destruction", where they should be destroyed.
Promotional video:
Further observations of this planet, as scientists hope, will help us understand what exactly will happen to the Earth in the future and reveal the secret of whether the planets can "survive" until the time the red giant turns into a white dwarf.