moderation:

Planetary Landscapes

Sunset on Mars Sunset colors on Mars appear opposite of those typically seen on Earth. The central blue glow appears when the Martian atmosphere scatters the sunlight, the same phenomenon that makes the Earth’s sky blue. Powdery dust suspended in the atmosphere gives the rest of the sky a copper color. The Sun appears only about two-thirds the size that it does on the Earth.

(via New York Times)