The Lower Atmosphere of Pluto Revealed

Matt_dk writes "Using ESO's Very Large Telescope, astronomers have gained valuable new insights about the atmosphere of the dwarf planet Pluto. The scientists found unexpectedly large amounts of methane in the atmosphere, and also discovered that the atmosphere is hotter than the surface by about 40 degrees, although it still only reaches a frigid minus 180 degrees Celsius. These properties of Pluto's atmosphere may be due to the presence of pure methane patches or of a methane-rich layer covering the dwarf planet's surface."

Re:What have we learned?

[Anonymous Coward]

methane doesn't smell of anything. its the other stuff such as SO2 that causes farts to smell.

if methane smelt bad we wouldn't have to add thiols(really stinky molecules) to mains gas to detect leaks.

Re:Quite a long and interesting article...

[Canazza]

um, Charon? [wikipedia.org]

Eris

[corsec67]

If Pluto gets called a planet, then Eris [wikipedia.org] would also be called a planet, since it is bigger than Pluto. Otherwise "Planet" would be a very arbitrary definition.

Re:liquid methane

[jschen]

The boiling point depends on the atmospheric pressure. Boiling points are typically reported based on sea level on Earth. With a much lower atmospheric pressure on Pluto, boiling points will drop.

Cold is absolute - Hot is relative

[drerwk]

Cold is an absolute term in that you can have absolute zero. Hot is a relative term in that there is no absolute hot, just degrees. Well maybe not - seems like the Planck temperature at 10^32 Kelvin might be an absolute hot. http://www.pbs.org/wgbh/nova/zero/hot.html [pbs.org] Makes sense given a Planck length and Planck time.

Re:So...

[GreenCow]

This is why we have different categories of planets.

Earth is the only Class M planet in the solar system.

Of course, with terraforming, Mars might join us in that someday.

Looking through: http://en.wikipedia.org/wiki/Class_M_planet

It seems like pluto should be a class K, or possibly a class D.