Mars, like Earth, has an atmosphere.  However, unlike Earth, Mars' atmosphere is composed mainly of carbon dioxide at a very low pressure.  Craters scar most of the surface of Mars.  This is because of the thin atmosphere which is unable to burn up most meteorites before they impact the surface.
 

The surface on Mars is very dry and because of this Mars has tremendous dust storms.  These storms, fueled by the heating of the planet's surface by the Sun, have winds that blow at very high velocities.  These winds disturb the small dust particles on the surface and cause them to become airborne creating the dust storm.  Scientists have observed dust storms as big as 50 kilometers tall!   Mars also has clouds composed of water.  These clouds, mainly observed around Mars' four volcanoes which are located near the equator, are composed of ice crystals.   If you were to live on Mars, what would you need to survive?