Monday, November 23, 2009

Mission to Vinland

Norse Ship
In the course of a work gig, I lately read up on Leif Ericson. I have noted him before on this blog, a gloomy Nordic presence at the space banquet. His claim to fame is as the second to last person to discover America, proof that mighty voyages do not always have mighty results. (The connotations of 'mighty' depending, of course, on perspective.)

To recap the story, Leif was the son of Eric the Red - an even more unwelcome guest at the space banquet, since he founded the Norse colony in Greenland that ultimately failed, its life support technology overwhelmed by the Little Ice Age.

Leif heard that another Norse seaman had sighted land west of Greenland, bought the man's ship, and went to see for himself. He found a couple of rather bleak islands, then one that was a lot less bleak. He dubbed it Vinland.

Up until 50 years ago this whole story hung only on the saga accounts, glimpsed along with King Arthur and the Trojan War across the misty frontier between history and legend. Then archeologists dug at L'Anse aux Meadows, on the northern tip of Newfoundland, and found a Norse outpost.

Leif's colonization effort was shortlived - mostly due to short tempered Vikings - and it is not certain that a 'colony' was the intent, rather than a base camp for resource exploitation. A chance encounter at sea more than 300 years later indicates that the Greenland Norse were still sailing as far as one of Leif's intermediate islands, Markland (possibly Labrador) to gather timber.

In short, the entire Vinland episode was a matter of a small frontier settlement looking for additional resources to tap in neighoring regions, a process that would be repeated scores of times after 1492. Leif Ericson, like Christopher Columbus, had no idea that he was 'discovering America.' But Columbus did know that he was looking for a major trade route, one that if it panned out would bring fabulous wealth to Spain (and, from his Genoese perspective, poke one in the eye of the Venetians).

Leif Ericson was not looking for a major trade route, only a supply source for a remote settlement. The Greenland Norse were too few to exploit it, and no one else had any practical need for it. In space terms, Vinland was just one more outer-planet moon that turned out not to warrant follow-up missions. A great story in its own right, but not, after all, a story of failed discovery.

Friday, November 20, 2009

The Weather on Mars

Dust Devil Trails on Mars
Hat tip to Anita for reminding me about this striking image, via Astronomy Picture of the Day, from the Mars Reconnaissance Orbiter. The swirly patterns are formed by dust devils that blow aside reddish surface dust to reveal dark material just beneath it.

I am old enough to be reminded of the Nazca lines, geoglyphs made by ancient peoples in a South American desert, that figured prominently in 'ancient astronauts' crankery. The patterns are entirely different, but you can imagine a playful intelligence at work here. 'Dust devil' is an apt term - think of the Tasmanian Devil in old Warner Bros. cartoons. Dust devils on Mars can reach 8 km in height, and have extended the life of Mars rovers by blowing the dust off their solar panels.

Once again Mars evokes an offworldly American Southwest. The Bat Durston theme is quintessentially SF, perhaps the very heart of 'Murrican SF, but oddly enough it never entirely applied to the old, rocketpunk era Mars. The old Mars, Percival Lowell's Mars, was a desert world indeed, but a desert of vast flat plains (the better for the canal system).

No one dreamed that Mars had both the highest mountain and the largest canyon in the Solar System. By pleasing irony, Lowell's observatory is not so far from the Grand Canyon.

Lowell's Mars was flat because it was a slowly dying world, its topography long since worn down by its desert winds. Real Mars fall from Earthlike grace more quickly, its atmosphere now too thin for its winds to wear down Olympus Mons. The forces that break mountains have faded along with the forces that make them. Now the winds of Mars produce only dust devils. (And the occasional planetwide dust storm.)

Yet the dust devils are also a reminded that Mars is not quite dead. Winds swirl across its surface; from time to time liquid water still flows there. It is still a world with weather.

Related Post: I noted in March that in spite of appearances, Mars is fiercely unlike Arizona.

Friday, November 13, 2009

Lunar Water: 'We Practically Tasted It'

IR Spectrum From L-CROSS
My post before last turns out to have been premature. I should have known better. Even at the press conference just after impact the L-CROSS team seemed just a bit chipper and smooth, especially for guys whose heavily promo'd sky show had just gone bust. Their media leaks a few days ago were also just a bit coy. (And given the subject, 'leak' is a singularly appropriate term.)

The sky show may have been a bust for the Earth audience, but it was no bust for the instruments aboard the L-CROSS probe, or the Lunar Reconnaissance Orbiter passing 50 km overhead.

Cutting to the chase, team leader Anthony Colaprete reports that that they found water, and 'We didn't find just a little bit, we found a significant amount.' In fact, 100 kg of water vapor were detected in the plume. (The illo above is from the Sky & Telescope article, where it is explained.)

Colaprete wouldn't give an estimate for what fraction of the soil that might be, but on the face of it that is quite a lot, and apparently counts only vapor - ice either vaporized by the impact heat, or perhaps sublimating from crystals exposed to space, especially if kicked up high enough to be hit by sunlight.

A brew of other compounds was also detected, one of the inevitable candidates being ethanol. I hope that pans out, if only to see the estimates of how many fifths are locked up in the lunar regolith. However, the first potable moon juice will surely come from a still tucked away in the life support plant.

Tuesday, November 10, 2009

On Colonization

Colony Planet from 'Firefly'
A post at SFConsim-l leads me to revisit a trope I have commented about here before. Space colonization, as imagined in SF and 'nonfiction' space speculation, is - surprise! - a riff on the English colonization of America, an experience shared by Clarke and Heinlein, albeit from different perspectives. Historically sort of colonization was driven first and foremost by cheap land.

This should be no surprise, any more than the American colonial analogy itself. It is like hydraulics. Provide a cheaper place to live and people will drift toward it, sometimes even flood toward it.

And the heart of the nutshell, as Heinlein once put it, is that there is no cheap land in space because there is no land at all. Land doesn't just mean a solid planetary surface (those are dirt cheap). Land means habitat, and in space the only way to have any is to build it youself. Which makes it expensive, especially since you have to build it up front.

Water can be pumped uphill, and people can be pulled toward expensive places to live by compensating attractions, or pushed there by pressures. But it is not a 'natural' process, and it can easily be reversed, hence ghost towns in rugged, played-out mining regions.

The sort of colonization envisioned in the rocketpunk era, most explicitly in books like Farmer in the Sky, but implicit in the consensus future history of the genre, is just plain unlikely, almost desperately unlikely, this side of the remote future or the Singularity, whichever comes first.

This is not the only possible sort of colonization. People have traveled afar, often spending their adult lives in some remote clime with no intention to settle there, marry, and raise a family, hoping instead to make their fortune and return home. The ones who don't make their fortune may end up staying, but that was not the plan.

Political colonialism often follows this pattern. The British colonized India, but I've never heard that any significant number of Britons settled there. (Human nature being what it is they did leave an Anglo-Indian population behind.)

A similar pattern has been common for trading outposts through the ages, whenever travel times have been prolonged. Even today, with one day global travel, people live abroad for years or even decades as expatriates, not emigrants. This, I believe, is a far more plausible scenario for the long term human presence in space than classic colonization. (And human nature being what it is, a mixed population will leave someone behind.)

Meta to this discussion - and not all that meta - is the delicate cohabitation of 'nonfiction' space speculation and science fiction. Space colonization has been driven first and foremost by story logic. For a broad range of story possibilities we want settings with a broad range of human experience. For this we want complete human communities, which means colonization in something like the classic SF sense.

But who are we trying to kid? Science fiction, particularly hard SF, is not known for engaging the whole range of human experience. This is no knock on it; all the branches of Romance are selective. The truth is that we want space colonies so that they can rebel against Earth, form an Empire, and generally play out History with a capital H, with lots of explosions and other cool stuff along the way.

I've suggested before on this blog that you can, in fact, get quite a lot of History without classical colonies. But another thing to keep in mind is that story logic doesn't necessarily drive real history. We may have an active spacefaring future that involves practically none of the story tropes of the rocketpunk era.

As a loose analogy, robotic diving on shipwrecks has done away with all those old underwater story tropes about divers trapped in a collapsing wreck, or bad guys cutting the air hose, but it has not at all done away with the somber magic of shipwrecks themselves, something the makers of 'Titanic' used to effect.

On the other hand, Hollywood has made two popular and critically acclaimed historical period pieces about actual space travel, and the stories are both an awful lot like rocketpunk.

Related posts: A Solar System for This Century.

Friday, November 6, 2009

Cold and Dry

Moon Above Desert
This seems to be the current forecast for the Moon's polar craters, as it presumably has been for the last few billion years, and will continue to be for the next few billion.

Not much (only one heavily processed image) has come out officially from the L-CROSS team since their mission scored a lunar bull's eye, minus the photogenic plume that was supposed to be the media highlight of the show. But in the grand old aerospace industry tradition of using Aviation Leak to get the story out, the L-CROSS team dropped some hints in the online Sky & Telescope about what is going on behind the scenes.

The impact did produce a plume, but it was about 10 times less massive than expected. Why it was so sparse is not yet known and may never be fully known, but new hypervelocity impact modeling suggests that debris may have gone more 'out' than 'up.'

There's also mention of the Centaur booster stage 'collapsed into itself when it hit.' I am not quite sure what to make of that last part. You'd expect any tank structure to 'collapse into itself' when it slams into the Moon at 1.5 km/s. But fans of kinetic weapons, including me, take note: There is a lot that we do not know about uber-fast impacts.

As for what was in the faint plume, Sky & Telescope gives contradictory hints, noting that the IR signature of water vapor is conspicuous (and implicitly absent), but also broadly hinting that when an L-CROSS public announcement comes, in a couple of weeks, the team may reveal that it did detect water. But not, I suspect, very much of it. What they did detect, rather oddly, is mercury.

The article also has one other interesting tidbit, though not from L-CROSS. Apparently an instrument aboard the Lunar Reconnaissance Orbiter determined that the surface temperature on the floor of those permanently shadowed are only about 35 K - much lower than anticipated, and making those spots the coldest known place in the entire Solar System.

And right in our local 'hood. How cool is that?