The fate of the Earth in the future would be grim, as eventually the Sun will become a massive red giant. Many astronomers see the Earth being swallowed up if ever that happens. Even if it isn't, the Sun would become so big that the Earth would be so near it. An old star shows what awaits the Earth in the future when that time comes.

The Sun today is in the main sequence of its life. It won't become a red giant for a few billion years more, so life on Earth today won't have any danger of seeing that happen yet. However, eventually it will happen. Once that happens, the Earth will be a very hot place if it has not been swallowed up yet by the Sun.

A preview of that could already be seen in a star system. Astronomers are looking into L2 Puppis, a star that was like the Sun five billion years ago. Professor Leen Decin of the Ku Leuven Institute of Astronomy said that the fate of the Earth is still uncertain. It could either be swallowed up by the Sun like Mercury and Venus, or else it would be so close to the Sun that it will be overheated, which will change much of the planet.

Astronomers are studying L2 Puppis using the ALMA telescope in Chile, according to the Ku Leuven site. L2 Puppis is around 208 light years away from the Earth. Ward Homan from Ku Leuven said that the star is around 10 billion years old. It is now a red giant with half of its mass gone because of its strong stellar wind.

At 300 million kilometers from the star a planet is orbiting it, as Phys Org reports. Astronomers are carefully observing the planet and star as it offers a preview of what the Earth will be like once the Sun has reached that time of its life. Whether the Earth will be swallowed or destroyed, or whether it will be heated up would be determined by the observations being made. What is clear is that the old star shows what awaits the Earth in the future. In another study, ALMA has seen the dust that is used for planet forming.