It was not so long ago that we were questioning the very existence of exoplanets, and now we are measuring their dark-sides. MIT News has a story about a recent paper discussing the findings of astronomers observing an exoplanet approximately 850 light years from Earth. About twice the size of Jupiter and tidally-locked with its host star, the exoplanet has a very strange water cycle. The article states:
While on Earth, water cycles by first evaporating, then condensing into clouds, then raining out, on WASP-121b, the water cycle is far more intense: On the day side, the atoms that make up water are ripped apart at temperatures over 3,000 kelvins. These atoms are blown around to the night side, where colder temperatures allow hydrogen and oxygen atoms to recombine into water molecules, which then blow back to the day side, where the cycle starts again.
The article and paper go into many more details, yet I am most impressed with this level of observation already possible using a spectroscopic camera aboard NASA’s Hubble Space Telescope. With the James Webb Space Telescope soon to go online, we can only hope for more fascinating insights into distant exoplanets.