Astronomers Confirm a Hot and Steamy Exoplanet

The Bad Astronomer writes "The extrasolar planet GJ 1214b was discovered in 2009 orbiting a nearby (40 light year distant) red dwarf star. The planet was quickly found to have a thick atmosphere, but it wasn't known at the time if the composition was water vapor or a hazy shroud of particulates. New Hubble observations confirm the atmosphere of the exoplanet is rich in water, comprising up to 50% of the atmosphere's mass (PDF). At 230 degrees Celsius, this means the planet is shrouded in steam."

Comments

The observations don't "confirm" anything

[solarissmoke]

New Hubble observations confirm the atmosphere of the exoplanet is rich in water, comprising up to 50% of the atmosphere's mass.

Actually, they do nothing of the sort. They just make water a more probable explanation for the observations. It says as much in the article.

These abstracts both state that the data indicates an atmosphere high in hydrogen and helium, but (taken from the second abstract):

Our observations disfavour a water-world composition, but such a composition will remain a possibility until observations reconfirm our deeper Ks-band transit depth or detect features at other wavelengths.