Earth to be burned to a crisp when the sun swells to 100 times its current size: scientists

The sun will grow to a hundred times bigger than it is today. Photo / Getty Images

Life on Earth will be burned to a crisp in five billion years' time.

By then, the sun will grow to a hundred times bigger than it is today, swallowing up Mercury and Venus, before it dies as a white dwarf star two billion years later, according to a new study.

This sneak preview into the future of our solar system was provided by a star 208 light years away from Earth, which has a "dying planet'"orbiting around it.

International astronomers used the most powerful radio telescope in the world to look at the star, L2 Puppis.

Five billion years ago, the star was very similar to the sun as it is today.

But now it is a red giant star, a dying star in the last stages of stellar evolution.

The team from Leuven, Belgium, presented the new findings in a paper published in the journal Astronomy and Astrophysics.

Professor Leen Decin, from the KU Leuven Institute of Astronomy, said: "Five billion years from now, the sun will have grown into a red giant star, more than a hundred times larger than its current size.

"It will also experience an intense mass loss through a very strong stellar wind.

"The end product of its evolution, seven billion years from now, will be a tiny white dwarf star.

"This will be about the size of the Earth, but much heavier: one teaspoon of white dwarf material weighs about five tonnes."

Although this metamorphosis into the giant star will change the solar system, scientists are unsure what will happen to the third rock from the sun.

"The fate of the Earth is still uncertain," Professor Decin added.

"We already know that our sun will be bigger and brighter, so that it will probably destroy any form of life on our planet.

"But will the Earth's rocky core survive the red giant phase and continue orbiting the white dwarf?"

The astronomers used the Alma radio telescope, which consists of 66 individual radio antennas that together form a giant virtual telescope with a 16km diameter, to study L2 Puppis.

"We discovered that L2 Puppis is about 10 billion years old," PhD student in Astrophysics Ward Homan said.

"Five billion years ago, the star was an almost perfect twin of our sun as it is today, with the same mass.

"One third of this mass was lost during the evolution of the star. The same will happen with our sun in the very distant future."

Researchers detected an object orbiting the giant star, 300 million kilometres from L2 Puppis, or twice the distance between the sun and the Earth.

The planet probably offers a unique preview of our Earth five billion years from now.

Further research about L2 Puppis and its planet will shed light on the final evolution of the sun and its impact on the planets in our solar system.