What is that, on the surface of the moon(looks like a valley)?

to see what i mean check moon pictures taken by appollo|||It is called a rille. There are hundreds of them on the Moon. They are caused by the ground slumping following a lava flow. One of the Apollo landings took place next to one called Hadley Rille.|||There are many things on the Moon which look like valleys, and they are (drum roll please!) valleys.|||Sea of Tranquility?|||well probably it's a watter park :D...wouldn't that be sweet?


maybe a crack in the surface|||moon surface looks like valley.but its not true.......they are only rocks....made up of salts...and dust...they even contain some chemicals.which makes them to look llike a valley.......but they are not valleys... becoz in moondue to no atmosphere and air they turn them selves like that......if you want try this.....take a stone......put in a fire for hours..make it very hot.......some for hours.......after that....make it cool (not with water)keep it in a room till it gets cooled......during cooling.....put some salt in it and place it in a air tight container keep it in sunlight... but dont allow any air....keepit in a dark room during night.........for months.......after that see whats happen to the rock.......... you will notice the answer..............