Water Vapor — and Maybe Even Rain — Found on Distant World Twice the Size of Earth

Loren Grush | The Verge
Monday, September 23, 2019

"Water vapor has been found in the atmosphere of a distant planet that’s just over twice the size of Earth. It’s the smallest world yet found with water in its surrounding atmosphere, and it’s possible that it even rains liquid water there," writes Loren Grush for The Verge. K2-18b is latest exoplanet find detailed in the Astronomical Journal, which was co-authored by EAPS postdoc Ian Wong along with MIT and other colleagues. "That makes this world a tantalizing candidate in the ongoing search for extraterrestrial life outside our cosmic neighborhood."

While finding water is a big deal for exoplanet researchers, it’s unlikely that this world is awash in oceans. In fact, it seems unlikely that the surface of the planet is rocky because of its size. “These planets are not going to look a thing like Earth,” Sara Seager, an exoplanet expert and professor at MIT who was not involved in this research, tells The Verge. “It’s definitely not rocky as we know a rocky planet to be.” K2-18b also orbits around a star very unlike our Sun. Altogether, these factors significantly decrease the chances that life could survive there.

Read the full story at The Verge. It was also covered in Science News, Nature News, and elsewhere.

Story Image: An artistic rendering of K2-18b. (Credit: Alex Boersma)