This expansion can crack rocks if there is no place else for the water to go. Ice also forms large masses called glaciers. Sand dunes are formed by wind and are moved by the wind. The sediment carried by the wind can impact other rocks and weather them as well. The last agent of erosion is impact cratering .
Impacts break up rock and throw it out of the crater.
On planets without atmospheres, there is no air to slow down and break up incoming meteors. Any particle that hits, down to those the size of neutrons and protons, will impact the surface and break up rock.