What will happen to the Earth when the Sun dies? A new study sheds light on us

Reading time: 2 minutes – spotted Science Alert

If you don't know it yet, we're sorry to interrupt you this way, but we must be very clear: our sun is not immortal and one day it will go out. Not all at once like a light bulb, but in a long process that will see it pass through the “white dwarf” stage, then the “red giant” stage, before its core collapses. It looks painful.

Researchers have a fairly detailed idea of ​​what happens when a star dies, but a slightly less idea of ​​what happens to the planets surrounding it. Our sun still has five billion years to go, but we'd better start preparing. An international group of physicists investigated this question A study published in the journal Monthly Notices of the Royal Astronomical Society Transferred by Science Alert.

The team of Amorrnath Ongwirujoit, a physicist at Naresuan University (northern Thailand), analyzed changes in the brightness of three… White dwarfs In the long term, to try to extrapolate the consequences on the surrounding planets. You will not be surprised to learn that these consequences are generally quite negative. In other words, we should hope that humanity will have moved on within five billion years.

The study explains that the final moments of our star's life will wreak havoc throughout the solar system, destroying Mercury, Venus and everything in its immediate vicinity. The sun will simply swallow them up and destroy them without detail.

Honey, pack your bags

A little further away, the Earth could survive. Everything will depend on its current orbit, which will undoubtedly be disrupted by the Sun's reduced mass and changed interactions with other planets. We talked here a month ago about how changes in Mars' and Earth's gravity will affect our climate.

But even if you could escape bulimia, Earth would no longer resemble the planet we know today. “It's not really clear whether the Earth can move away fast enough before the sun can catch up with it and burn it up. But [si elle le fait]Earth would lose its atmosphere and oceans and would no longer be an enjoyable place to live., Nuance Boris Gancika physicist at the University of Warwick, located in Coventry (central west England).

“This is how the world ends”

So scientists made all these painful predictions by observing changes in the brightness of white dwarfs. These fluctuations mean several things. If it increases and decreases regularly, perhaps something orbits the star… perhaps a planet, or rather the remains of this planet. “Previous research has shown that when asteroids, moons and planets approach white dwarfs, the intense gravity of these stars tears these small planetary bodies into smaller and smaller pieces.”specifies amornrat unguirujuit.

Based on seventeen years of data collected about the three stars at the end of their lives, the researchers were able to establish what looks like a common pattern: the first irregular drops of light that could be caused by giant clouds of gradually crushed debris, until they disappear. , absorbed by the white dwarf.

“The sad news is that the Earth will likely be swallowed by the expanding Sun, before it becomes a white dwarfalso details Boris Jancic. For the rest of the solar system, some asteroids between Mars and Jupiter, and perhaps some of Jupiter's moons, may be dislodged and travel close to the future white dwarf to undergo the shredding process we studied. There you go, now you know how the story will end.