KU Leuven astronomers predict Earth’s chances of survival

Summary

The sun will become so big that life on Earth will prove to be impossible, according to a new article co-authored by astronomers at KU Leuven

Five billion years and counting

An international team of astronomers, including researchers from the University of Leuven (KU Leuven), is investigating a star called L2 Puppis to get an idea of what will happen to Earth in billions of years.

In an article published in Astronomy & Astrophysics, the researchers predict that in five billion years, the sun will have grown into a red giant star, more than 100 times larger than it is now. But because of a strong stellar wind, the sun will be reduced to a white dwarf star about the size of the Earth two billion years after that.

This evolution will have a dramatic impact on the solar system, destroying Mercury and Venus, among other celestial bodies. “Our sun will become bigger and brighter, so it will probably destroy any form of life on our planet,” said KU Leuven professor Leen Decin in a statement. “But we’re unsure if the Earth’s rocky core can survive the red giant phase in order to continue orbiting the white dwarf.”

The astronomers discovered that the L2 Puppis, which is near Earth in astronomy terms, is about 10 billion years old. Five billion years ago, it was an almost perfect twin of our sun. One-third of its mass was lost during the evolution of the star, as is expected to happen to the sun.

Meanwhile, 300 million kilometres from L2 Puppis – twice the distance between the sun and the Earth – the researchers detected an object orbiting the giant star. This is probably a planet that offers a unique preview of our Earth in five billion years.