On a scorching day of sun and dust when the arid wind is sucking the energy out of your body, you can feel like you're shrivelling up and just want to get out of the heat somehow. A simple glass of water is hugely more precious in that environment than it would be back in Canada where we not only swim in more-or-less-drinkable water, we boat in it. Lake Superior on its own contains about 12,100 cubic kilometres of the stuff! How many bottles of water would that be? Only about 1.7 million for every person alive today on planet Earth!
Ohhh... I got distracted. I do love the lake, though. And it's a reminder how astonishing it would be to find water flowing on Mars, which does appear to be more barren and desiccated than anywhere on Earth. Yet, NASA scientists have found strong evidence that water is still flowing in recent times. The atmosphere is so thin, little more than a vacuum with faint suggestions of carbon dioxide, that any liquid water on the surface should soon boil-and-freeze. Out in the Red Planet Cafe you'll see it's true. If you order tea, you'd better drink it as soon as I've poured it out, or you'll have wasted your money.
Seriously though, I've been reading Mars Up Close: Inside the Curiosity Mission by Marc Kaufman of National Geographic. It's more than just fascinating: it follows the story of the Curiosity rover's journey, landing and exploration so vividly that I can almost see the rusty, dusty hills of Gale Crater without looking at the pictures (of which there is a hoard).
So far, the mystery of Mars appears to be this: So, the planet did have a tremendous amount of water in its distant past, enough to make a deep ocean. And most scientists believed that most of the water vanished long ago into the rocks, evaporating and dissociating into space, freezing into the polar caps. Climatologists have run computer models of the climate on Mars back then to verify this.
But now Curiosity's discoveries (of course, actually the discoveries of the scientists and engineers who program her) suggest more and more convincingly that there was water flowing in the recent past - by which they mean less than a billion years ago. And the newest discoveries of water streaks down mountainsides shows that it's still happening! So the climatologists and the dry-Mars theorists are scrambling to revise their models or challenge the new theory.
|Dark, narrow streaks on Martian slopes discovered by the Curiosity rover are inferred to be formed by seasonal flow of water on contemporary Mars. The streaks are roughly the length of a football field. Image credit: NASA/JPL-Caltech/Univ. of Arizona|
What does it have to do with us, though, practically speaking? Quite a lot, I'd say. For a start, it would mean that my cafe doesn't have to depend on the annual supply-drop of water anymore - I can go and gather up my own water by heating the frozen soil and collecting the water vapour! That's what any Mars colonists could do, too.
On a more meaningful note, doesn't it show you how - in the middle of our getting on with life as usual, thinking we have it mostly mapped out and understood - surprise! Reality spins us around and makes us rethink how we understand the world, or the people we meet.
More practically, also, more water on Mars means that colonising it will be more possible, and that is bound to affect the rest of the human race, not just those embarking on that great adventure. Just think of the effects on history of the movement of settlers across the Atlantic (for better or for worse, some might say).
That's why I'm staying tuned to Curiosity's own 'Discovery' channel.