perfidy

The recent announcement that NASA scientists have concluded that surface of Mars - at least where the opportunity rover is exploring - was once a wet place has space enthusiasts rather excited. For those who don't see why this is a good thing, nevermind. It's a space thing and you wouldn't understand.

Just kidding. The fact that at least one place on Mars was certifiably wet has many implications. It means that there was once another place in the solar system that was habitable. This does not by any means guarantee that there was at any point life on Mars, but by studying the geological history of Mars, we can learn things that we could never learn by studying the Earth alone. Science moves much faster when researchers have two things to compare. We will learn from Mars how life didn't evolve under conditions similar to those on Earth, and from this learn more about how it did on Earth. We can learn about climate, and how it goes wrong. (Maybe Mars was hit by global warming? The sky is falling!)

Also, the fact that there was once surface water raises the big question, "Where is it now?" If this water is bound up in the rocks, or in subsurface permafrost or ice deposits, that means that we could potentially get at it, and use it for human settlements or even for terraforming.

And besides, it's just plain cool to imagine what Mars might have looked like with oceans and seas. Like this:

A view down the Valles Marineris.

Or imagine sailing on these seas:

Or sailing up to the very base of the tallest mountain in the Solar System: