The Exoplanet K2-18b is a super-Earth twice the size of our eight-fold planet. It's also wet or at least the sky around it. The researchers found evidence of water vapor when they captured data collected by NASA's Hubble Space Telescope (19459015) in 2016 and 2017 through an open-source, far-planet analysis algorithm developed by them. Their results were published Wednesday in the journal Nature.
Water vapor was found in the atmosphere of other planets, but this is the first time such moisture has been discovered on a planet in the habitable zone of its star, where temperatures could be tolerable, if not exceedingly pleasant.
More data is needed to determine what type of cloud cover the planet has, how much water is in the atmosphere, and whether the material actually forms large bodies of water on the planet's surface here on Earth.
"It is quite possible that this is a water world," said co-author Giovanna Tinetti, a professor of astrophysics at University College London. However, she warned that it was too early to confirm the presence of a kind of surface ocean.
It is estimated that temperatures on the planet could be between minus 100 degrees Fahrenheit (minus 73 degrees Celsius) and 150 degrees Fahrenheit (66 degrees Celsius). This is of course a wide range, but it is not too far removed from the conditions we see here on Earth.
"However, this planet is not a second earth," said Angelos Tsiaras, a senior researcher at UCL, to reporters on Tuesday. "It circles around a so-called red dwarf star … in this environment, the space weather is more hostile than here on earth."
also called M dwarf stars, are smaller, cooler and darker than our sun. They are also known to often cause strong solar flares that could threaten the radiation of orbiting planets. Fortunately, K2-18, which is 110 light-years from Earth, is not as bright as other M-dwarf stars.
"Especially this is not very active at all," said Ingo Waldmann, lecturer in extrasolar planets at UCL and co-author of the newspaper. "We did not see any flaring."
The analysis of starlight passing through the Earth's atmosphere also revealed hydrogen and helium. Future studies could determine if there are other molecules, such as nitrogen and methane, that are closely related to life as we know it.
Researchers are confident that the upcomingwhich will be significantly more powerful than Hubble, will provide an even clearer view of what happens on distant exoplanets. If the conditions are right, you can even add K2-18b to an interstellar itinerary in the distant future.
"Our discovery makes K2-18b one of the most interesting targets for future studies," said Tinetti.
Originally published on September 11, 10 am, PT.