Take a look at the picture above. You might wonder what is so special about it, no? Just a bunch of stones, or what?
Well, the thing is that the stones are round, just like pebbles on a beach. But where is the beach? and where is the sea? There is no water around. There is no water to be seen in the far distance. In fact, there has not been any water for millions of years. So how come these stones are so round?
Now, I am no geologist, and surely no pebble-expert and I am not sure if pebbles can be formed in the absence of water, so if someone knows, please tell me.
Recently, in 2008, the Phoenix Lander discovered water on Mars. But the picture above has been taken back in 2006 and as far as I am concerned it tells something about Mars.
To prove that the pebbles really are abundant, here are some more photo's. (Also notice the strange joker-like rock in the corner.)
Alle examples are taken from PIA01907, but more pebbles can be found here.