Weather Forecast For Exoplanets: How ‘Alien Worlds’ Compare To Climate Here On Earth

A forecast of cloudy with a chance of searing heat – that’s what a day on a distant planet looks like, according to astronomers. For the first time, scientists have mapped the daily climate cycles of six large exoplanets – planets orbiting stars other than the sun – and it’s making Earth’s extreme weather feel like a breeze. Their research was published Tuesday in Astrophysical Journal.

The scientists used data gathered by NASA’s Kepler Space Telescope, launched into orbit in 2009 and sent on a mission to find Earth-like planets beyond the solar system, to look for evidence of weather changes on known exoplanets. Most of the exoplanets observed were large and extremely hot -- upwards of 2,900 degrees Fahrenheit -- which means they can’t support life but are excellent for studying atmospheric changes because of their size and close proximity to their stars, according to the new study from researchers at the University of Toronto, York University in Toronto and Queen’s University Belfast in Northern Ireland.

“We determined the weather on these alien worlds … by measuring changes as the planets circle their host stars, and identifying the day-night cycle,” Lisa Esteves, a Ph.D. candidate in astronomy and astrophysics at the University of Toronto and lead author of the study, said in a statement. “We traced each of them going through a cycle of phases in which different portions of the planet are illuminated by its star, from fully lit to completely dark.”

Scientists said that as techniques for measuring alien weather systems advance, they aim to study the atmospheres of smaller, more Earth-like, exoplanets, which could aid astronomers in discovering extraterrestrial life.

The exoplanets researchers observed were all located near their stars, and they rotate counter-clockwise. Their rotation causes atmospheric winds to move eastward, which results in cloud cover during the night but clear skies during the day.

Astronomers have discovered around 1,832 confirmed exoplanets as of April 30, according to NASA. Scientists believe if there is other life in the universe, their best bet is to locate exoplanets with atmospheres similar to Earth’s, with water vapor, carbon dioxide and, most importantly, oxygen.