Water detected in 51 Peg b's atmosphere

[UmbralRaptor]

To preemptively kill silly hype, this is about a hot Jupiter, so it's not aliens.

Astrobites writeup

Actual paper on ArXiv

High resolution ~3.2 micron spectra of 51-Peg picked up some reflection features of the planet. They found water vapor (~100 ppm), but no methane or carbon dioxide (upper limits on concentrations unclear). The measurements also pinned down the mass and orbit a bit better, (inclination frustratingly close to transiting, ~0.476 MJ making it more Saturn-like, and no eccentricity to speak of) Rotational speed is <5.8 km/s, so for any plausible radius the sidereal days are longer than Jupiter's. (Tidal locking suggested, but far from confirmed)

[Bill Phil]

Considering water is in a lot of places, I wouldn't be surprised.

Really awesome that we can actually find out what compounds are in an atmosphere. Spectroscopy and related techniques are some really cool stuff.