SoylentNews

takyon [soylentnews.org] writes:

Another study has cast doubt on the habitability [nasa.gov] of an Earth-like exoplanet in the "habitable zone" of a red dwarf, in this case Proxima Centauri [wikipedia.org] specifically:

At only four light-years away, Proxima b is our closest known extra-solar neighbor. However, due to the fact that it hasn't been seen crossing in front of its host star, the exoplanet eludes the usual method for learning about its atmosphere. Instead, scientists must rely on models to understand whether the exoplanet is habitable.

One such computer model considered what would happen if Earth orbited Proxima Centauri, our nearest stellar neighbor and Proxima b's host star, at the same orbit as Proxima b. The NASA study, published on July 24, 2017, in The Astrophysical Journal Letters [doi.org] [DOI: 10.3847/2041-8213/aa7eca], suggests Earth's atmosphere wouldn't survive in close proximity to the violent red dwarf.

[...] In Proxima Centauri's habitable zone, Proxima b encounters bouts of extreme ultraviolet radiation hundreds of times greater than Earth does from the sun. That radiation generates enough energy to strip away not just the lightest molecules — hydrogen — but also, over time, heavier elements such as oxygen and nitrogen.

The model shows Proxima Centauri's powerful radiation drains the Earth-like atmosphere as much as 10,000 times faster than what happens at Earth.

Previously: "Earth-Like" Exoplanet Found in Habitable Zone of Proxima Centauri [soylentnews.org]
Proxima b May Have Oceans [soylentnews.org]
Researchers Suffocate Hopes of Life Support in Red Dwarf "Habitable Zones" [soylentnews.org]
Proxima B Habitability Study Adds Climate Model [soylentnews.org]

Related: MAVEN Results Find Solar Wind and Radiation Responsible for Stripping the Martian Atmosphere [soylentnews.org]

Original Submission