This picture, taken by the Curiosity rover on Mars, shows an object that very much looks like a human finger, complete with fingernail.
Obviously, we're only seeing one side of the object, so we cannot tell if it still looks like a finger from all sides. Some have suggested that it's a fossilized finger from a Martian or a broken-off finger from a Martian statue.
Or is it just an odd rock that from this vantage point happens to look like a finger?
