In a tantalizing first, scientists have discovered water at a planet outside our solar system that has temperatures suitable for life.
Two research groups announced that they’ve found water vapor in the atmosphere of a planet 110 light-years away in the constellation Leo. It’s the only exoplanet known so far to have both water and temperatures needed for life, the University College London team reported in the journal Nature Astronomy.
But lead author Angelos Tsiaras stressed, “This is definitely not a second Earth.” Its star and atmosphere are so different than ours, “Earthlike conditions are not possible,” Tsiaras said. “The only question that we’re trying to ask here … is the question of habitability.”
A Canadian-led team announced similar findings, even suggesting that it might even be raining there. “This represents the biggest step yet taken toward our ultimate goal of finding life on other planets, of proving that we are not alone,” said the study’s lead astronomer, Bjorn Benneke of the University of Montreal.
Discovered in 2015, the planet known as K2-18b is twice the size of Earth with eight times the mass. While it’s thought to be rocky, no one knows whether water’s flowing on the surface. Its star, a red dwarf, is smaller and cooler than our sun.
Nonetheless, Tsiaras said K2-18b could help determine, “Is the Earth unique?”
K2-18b takes 33 days to orbit its star, so one year there is one month here. At this distance, temperatures range from minus-100 degrees to 116 degrees Fahrenheit.
The star, glowing red in the day sky, is believed to bombard the planet with radiation harsh enough to quickly inflict any human visitors with cancer, although “life there may have evolved differently” in order to survive, noted the London team’s Ingo Waldmann. “Maybe not quite your vacation destination just yet,” he joked.