The Mysterious Case of the Evaporating Sub-Neptune World
Astronomers sifting through data from a NASA planet-hunting satellite have hit the jackpot: a common type of planet 131 light-years away called TOI-1759b, with an extremely uncommon story to tell. Thanks to its close proximity to its host star, the planet's atmosphere appears to be evaporating into dead expanse of space—extremely fast, by astronomical standards.
Watching this radiation-induced “photoevaporation,” reported on in a new study led by Eder Martioli at the Laboratório Nacional de Astrofísica in Brazil, could help us understand one of the weirdest mysteries in modern astronomy. As we continue to discover more planets out there beyond our solar system—what we call exoplanets—there’s an inexplicable absence of planets the size of Neptune or slightly smaller (“sub-Neptunes”) in orbits close to their host stars.
Just by sheer probability, we ought to be discovering more of these mid-sized planets that manage to complete entire orbits around their host stars in just a few days. Instead, we’re left with a planetary dead zone for medium planets that astronomers call the “sub-Neptune desert.” All of this begs the question: How can there be so many medium-sized planets out there, but so few medium-sized planets in orbits close to their stars?
This isn’t simply a compelling question for astronomers who want to nerd out about planetary formation. Measuring atmospheric evaporation might also help us narrow our search for alien life in the universe—something many more people can get behind.
https://www.thedailybeast.com/the-evaporating-atmosphere-of-the-toi-1759b-sub-neptune-exoplanet-could-tell-us-how-habitable-planets-form?ref=home
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