(MOVIE SOUND) As the storm clouds gather for a titanic battle, a young man named Perseus is thrust into the middle.

VOA: standard.2010.04.08

One of these satellites, CloudSat, has given the first glimpses of the middle layer of clouds in the Earth's atmosphere.

ECONOMIST: Climatology

Gas clouds in the middle of the galaxy are, everyone agrees, partly ionised: radiation flying through has battered electrons off some of the atoms in the gas.

ECONOMIST: Here be serpents