Discovery of "Future Earth" 4,000 light years away
What will happen to the Earth in 8 billion years if it is not swallowed by the Sun?
The answer may lie in the image of a distant planet recently discovered by astronomers. KMT-2020-BLG-0414, located 4,000 light-years from Earth, is a rocky planet orbiting a white dwarf—the remnant of a star. Our Sun is expected to turn into a white dwarf in 5 billion years.
Before that happens, the Sun will become a red giant, engulfing Mercury, Venus, and possibly Earth and Mars. If it escapes this fate, Earth may become like the newly discovered planet, gradually drifting farther and farther away from the cold remnants of the Sun.
"There is currently no consensus on whether Earth can avoid being swallowed by the Sun in 6 billion years," said Dr Keming Zhang, an astronomer at the University of California San Diego and lead author of the study. "In any case, Earth can only sustain life for about 1 billion years, when the oceans will evaporate due to the runaway greenhouse effect - long before it is at risk of being swallowed by a red giant star."