We’ve got a date when the sun will destroy Earth – sue us if we’re wrong
Scientists may have discovered when and how the Earth will be destroyed (Picture: Getty/Metro) The date the world will end has been nailed down – but you still have time for quite a few pints before our planet Earth is screwed. Our life in the solar system relies on the sun, but the fiery planet has an expiration date, and so do we.
New research suggests that the Earth will be destroyed when the sun dies around five billion years from now. Astronomers at the University of St Andrews have been digging into what happens to planets after the death of their star, offering a glimpse into the future of the solar system. They say it was like using a ‘time machine’ to discover the future of the solar system.
The research team at the Scottish university used the NASA/ESA/CSA James Webb Space Telescope to watch a Jupiter-sized exoplanet, called WD 1856 b, transit its ‘dead’ host star. They were able to measure the planet’s mass and temperature and even detect its atmosphere. To view this video please enable JavaScript, and consider upgrading to a web
browser that supports HTML5 video Up Next Previous Page Next Page The researchers found that the planet is ‘significantly warmer’ than expected and determined how it most likely reached its very tight orbit around the white dwarf. The team explained that the sun will run out of hydrogen fuel in its core and swell up more than 100 times larger than it is now into a red giant star around five billion years from now.
It will then shed its outer layers and end its life as a white dwarf star. Mercury, Venus, and possibly the Earth will be destroyed by the red giant, according to the study published in the journal Nature. But like with most things in space, there are still many unknowns. One of them is the fate of more distant planets like the gas giants.
Gas giants are mainly made of hydrogen and helium, and the most famous of their kind include Jupiter and Saturn. They explained that finding and studying planets in orbit around the remnants of Sun-like stars after their death is a way of learning what might happen in our own Solar System in the far future.
What’s the ‘oddball planet’ WD 1856 b? The exoplanet with a clunky name was discovered in 2020, orbiting the white dwarf called WD 1856+534 around 80 light-years from Earth, a distance that would take over one million years to travel using modern rocket technology. It was spotted using the £216 million NASA Transiting Exoplanet Survey Satellite (TESS) and the Spitzer Space Telescope.
Study lead author Dr Ryan MacDonald, from the University of St Andrews, said: ‘The planet is quite the oddball. ‘It’s about the size of Jupiter, but the white dwarf it orbits is the size of Earth, so the planet is seven times larger than its star.’ What is so unusual about WD 1856 b is its ‘extremely close’ orbit around its host star, a distance 50 times closer than Earth orbits the sun, Dr MacDonald said.
It was the first such discovery of an intact planet closely orbiting a white dwarf. But Dr MacDonald said if WD 1856 b had originally been orbiting at that distance, it would’ve been obliterated while the star was a red giant. The researchers wanted to know how it survived the death of its host star and end up in its current position.
The new study used Webb to watch the planet passing in front of its star in a so-called ‘grazing transit’ where the very top of the planet partly overlapped the star. The transit yielded unique information about the planet’s mass and temperature, estimating the planet at between four and 11 times as massive as Jupiter.
Light from the star passing through the planet’s atmosphere picked up information about the atmosphere’s chemical composition. Dr MacDonald said: ‘We’re used to looking back in time when we use telescopes, but this is the first time we have been able to look forward to what might happen to the outer planets around the remnant of a Sun-like star.
‘It’s like using a time machine to peer into the distant future of our Solar System.’ It all boiled down to projecting the object’s temperature back in time and determine how the planet had a temperature of around 400 Kelvins or 126C, around 240 degrees hotter than it would be if its only sourcoe heat was the light from the white dwarf.