Astronomers have discovered a new Earth-like planet, orbiting a distant star 4,000 light years away in the constellation Sagittarius. This rocky planet, roughly the same size and mass as Earth, circles a white dwarf star, offering potential clues to Earth’s own future as our sun eventually enters its final stages of life.
The discovery, led by a team from the University of California, Berkeley, raises new possibilities about the survival of Earth and the future of life in our solar system. As our sun approaches the end of its lifecycle, it will expand into a red giant, likely consuming Mercury and Venus. But the fate of Earth has remained uncertain. The existence of a planet like this, orbiting a white dwarf, suggests that Earth too might avoid being engulfed by the sun. This could shift the solar system’s habitable zone farther out, with some moons around Jupiter and Saturn, like Europa, Callisto, and Enceladus, potentially becoming safe havens for future generations.
What are White Dwarfs?
A white dwarf represents the final stage of a star’s life. After a star uses up its nuclear fuel, it sheds its outer layers and contracts, becoming a dense white dwarf. Our sun is expected to undergo this transformation billions of years from now, though it will expand first, threatening nearby planets. Whether Earth will survive the sun’s red giant phase is unknown, but this discovery provides hope that it might escape complete destruction.
Published in Nature Astronomy, the study was conducted using the Keck Telescope in Hawaii. The researchers observed a system named KMT-2020-BLG-0414, which contains a white dwarf with an Earth-like planet orbiting twice as far as Earth does from the sun. The system also includes a brown dwarf, a large planet about 17 times the mass of Jupiter.
Jessica Lu, an associate professor of astronomy at UC Berkeley, explained, “Whether life can survive on Earth through that (red giant) period is unknown. But certainly, the most important thing is that Earth isn't swallowed by the Sun when it becomes a red giant.”
The Future of Earth and Life Beyond
Keming Zhang, the study’s lead author and now a postdoctoral fellow at UC San Diego, added that even if Earth is spared from the sun’s expansion, it may not remain habitable. In about a billion years, Earth’s oceans will likely evaporate due to a runaway greenhouse effect, long before the sun’s red giant phase. If humanity needs to find refuge beyond Earth, one possibility lies in the outer solar system. As the sun’s habitable zone moves outward, Jupiter’s and Saturn’s moons might become more suitable for life.
Discover the latest Business News, Sensex, and Nifty updates. Obtain Personal Finance insights, tax queries, and expert opinions on Moneycontrol or download the Moneycontrol App to stay updated!
