Will Earth still exist 5 billion years from now?
What will happen to Earth when, in a few billion years' time, the Sun is a hundred times bigger than it is today? Using the most powerful radio telescope in the world, an international team of astronomers has set out to look for answers in the star L2 Puppis. Five billion years ago, this star was very similar to the Sun as it is today.
This metamorphosis will have a dramatic impact on the planets of our Solar System. Mercury and Venus, for instance, will be engulfed in the giant star and destroyed.
"But the fate of the Earth is still uncertain," continues Decin. "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?"
|Schematic view of the candidate planet's orbit in L2 Puppis disk |
[Credit: © P. Kervella (CNRS/U. de Chile/Observatoire de Paris/LESIA)]
"We discovered that L2 Puppis is about 10 billion years old," says Ward Homan from the KU Leuven Institute of Astronomy. "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."
300 million kilometres from L2 Puppis -- or twice the distance between the Sun and the Earth -- the researchers detected an object orbiting the giant star. In all likelihood, this is a planet that offers a unique preview of our Earth five billion years from now.
The study is published in Astronomy & Astrophysics.
Source: KU Leuven [December 08, 2016]