In Search of the Next Frontier
Thursday, September 25, 2008
In our own halting, herky-jerky fashion, human beings are becoming inhabitants not just of a planet but of a solar system.
We have scouts out there, robotic spacecraft, including a couple winging their way into the interstellar void. We have big plans for sending astronauts once again beyond low-Earth orbit. For an exploring species, one driven by curiosity and material desires, this solar system is a target-rich environment. There are places to go, things to see.
There is, for example, Titan, the great moon of Saturn, with its weather-carved landscape, its methane rain, its valleys and rivers and lakes. Too cold for liquid water and for life as we know it, it is still a chemist's paradise, rioting with the kind of carbon-based molecules that suggest that this is a universe primed for life's efflorescence.
There's Jupiter's moon Europa, covered with what look to be icebergs shifting above a deep subsurface ocean.
There's Enceladus, another Saturnine moon, a weird-looking place with part of its face smooth, part ragged, and the surface erupting in geysers of ice, like a cold Yellowstone.
Of course there's Mars, which, though chilly, rusty, nearly airless and blasted by radiation, is by comparison with Venus or Mercury a veritable Club Med. We've found water ice on Mars, and there may be some liquid stuff deep underground. The planet has just about as much land surface as Earth. A Martian day lasts about 24 hours. On the warmest days, the air temperature is about the same as at a Green Bay Packers playoff game at Lambeau Field.
Never getting much ink, but still intriguing, are the asteroids, some of them hundreds of miles across, a few of them crossing the path of Earth. They may be like giant tanker ships of exploitable resources, waiting for someone to bring them in to port.
Much closer to hand, and perhaps unfairly unfashionable these days, is our own moon. It could potentially supply raw materials to fuel fleets of spacecraft. The far side has the nice feature of being radio-quiet, protected from our wireless chatter and other electromagnetic noise. It's the perfect place to put a telescope to scan the deep universe.
This solar system is not entirely ideal -- it's chockablock with hostile environments and not a single benign location apart from our own to plop down and hold a cookout. But it is a scientific wonderland and, perhaps, full of practical opportunities that we simply haven't envisioned. If nothing else, it beckons us to great adventures.
There are many people who make the plausible argument that we can't afford to throw money into space when we have so many practical problems on terra firma. Finding water on, say, Europa may seem esoteric to earthlings who don't have clean drinking water at home.
But we already are, in our own half-interested way, a space-faring civilization. The basic principles of spaceflight are known to us. The big, overriding question is: Where do we go from here?
That question was simpler half a century ago, on the first day of October, 1958, when the National Aeronautics and Space Administration began operations. At that point we just needed to get into space, up beyond the atmosphere, into that high frontier.