http://news.yahoo.com/blogs/sideshow/scientists-ancient-martian-rock-full-water-223144105.html

So this article says that a rock full of water came from Mars to Earth. How is that possible?

EDIT:  Obviously I didn't read the article carefully enough.

So with that said, I wonder how Earth-rocks our volcanoes has sent across the galaxy.

http://news.yahoo.com/blogs/sideshow/scientists-ancient-martian-rock-full-water-223144105.html

So this article says that a rock full of water came from Mars to Earth. How is that possible?