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David Darling's Newsletter #32


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October 3, 2005



It's been a couple of months since the last newsletter and an amazing amount has happened in that time. Two major hurricanes have struck the Gulf coast, ratcheting up the debate about the possible effects of global warming. Astonishing new discoveries have been made around Saturn by Cassini. Another deep space probe, Japan's Hayabusa, has arrived at its target — the asteroid Itokawa — in preparation for bringing back the first samples of one of these flying mountains to Earth. Astronomers have spotted a pulsar hurtling out of the Milky Way Galaxy. Meanwhile, back on Earth, scientists have discovered the first fossil bones of our nearest extant relative, the chimpanzee, and recorded, for the first time on film, a live giant squid in the ocean depths. Plenty to catch up on then!


Heated Words and Global Warming

Not everyone is yet sold on the idea that the Earth is warming up or, if it is that, we pesky bipeds are to blame for it. But you won't find many professional climatologists and meteorologists in the camp of the nay-sayers anymore. Fast-melting glaciers around the world, unprecedented heat waves and droughts from southern Europe to Australia, ocean warming, and a spectacular loss of Arctic and Antarctic ice offer compelling evidence that our planet is entering a period of deep ecological uncertainty. Last week, researchers from the National Snow and Ice Data Center (NSIDC) in Boulder, Colorado, gave the latest batch of results on sea ice in the Arctic, showing that the September 2005 coverage was the lowest since records began. Given the current rate of shrinkage — about 8 percent per decade — there'll be no sea ice at all during the summer of 2060. Not only will all that ice have turned into water during the summer months, raising sea levels, but the lack of a highly reflective ice cover will speed up the warming process by absorbing more of the Sun's rays.

Of course, researchers know they have to tread carefully when interpreting these kind of data. The Earth's climate goes through natural cycles that don't have anything to do with human activities. But the amount of the Arctic summer sea ice has been trending down for several decades and it's dropped consistently for the past four years. The coverage is now a fifth less than the 1978-200 average. Mark Serreze at the NSIDC seems pretty convinced about the culprit. He told the BBC: "I think the evidence is growing very, very strong that part of what we're seeing now is the increased greenhouse effect. If you asked me, I'd bet the mortgage that that's just what's happening."

Is global warming to blame for hurricanes Katrina and Rita? There's no way to tell with isolated events like these. The general opinion seems to be that global warming will lead to more extreme weather of the kind we've been experiencing but we can only wait and see if the next few years bring more city-busting monsters of Katrina's ilk barrelling across the Atlantic.

The big thing that concerns scientists is that we may be close to, or even at, some tipping point, beyond which the situation will get rapidly, and maybe irreversibly, worse. There's already some fear that in the disappearance of sea ice, leading to greater absorption of the Sun's heat by open water, we're seeing one of the projected positive feedback effects beginning to kick in. Other possible tipping points are a melting of permafrost, releasing methane — a potent greenhouse gas — and a switch from forests being net absorbers of carbon dioxide to net producers, as logging companies relentlessly hack down the rainforests of Amazonia and Indonesia.

Personally, I think human activity does pose a grave and imminent threat to the planetary biosphere. But I also think — and it's no more than a gut feel — that it isn't too late to do something about it. Humans aren't separate from the global (Gaian) superorganism, like a virus attacking it from outside; we're an intimate part of nature and we — that is, the living Earth — will find a way to bring itself back into balance. I suspect and hope we're part of an inherently self-correcting system. Perhaps one of these days we'll wake up to find that we've come to our collective senses and begun tackling the real problems that face us instead of finding more ingenious ways to blow each other up. Or is that just being a little too naive?


Back to the Future

If NASA's recently announced plans to return to the Moon have a strangely familiar ring to them, that's hardly surprising. The Agency's Administrator has referred to them as "Apollo on steroids". Gone will be the Shuttle (by 2010) and in its place (by 2012) an Apollo-like Crew Exploration Vehicle (CEV). Think of the CEV as a beefed-up Apollo Command and Service Module. It will be NASA's all-purpose craft for human spaceflight in the next decade and beyond. Three astronauts and cargo will be able to travel to and from the International Space Station, having been launched from Earth by a new heavy-lift vehicle. For the Moon trip, four astronauts will occupy the CEV, which will be attached to a lunar lander. Once in Moon orbit, the lunar lander will descend to the surface with three or four astronauts aboard for a stay on the Moon of up to a week. NASA sees the first crewed return to the Moon by 2020, then a series of visits that may lead to the establishment of a small outpost that could be occupied by crews in stints lasting as long as six months each.

Which all sounds great, until you start to figure out the cost. $100 billion is the conservative estimate for getting back to the Moon. Are future US Administrations and Houses going to be willing to cough up the extra billions per year that NASA will to need to carry through these ambitious plans without cancelling other projects such as robotic missions to the planets and Earth resources programs? Apollo was a fantastic adventure and achievement but it produced precious little science per buck. You could launch dozens of space observatories and probes to Mars, Pluto, the Kuiper Belt, and elsewhere in the Solar System for the cost of "Apollo II". If NASA's new plans for human spaceflight, along with those of Europe, Russia and China, really do mark the beginning of man's colonization of the cosmos, then fine, let's make sure it's properly and continuously funded, and not done at the expense of science-rich robotic missions.


Strange New Worlds

Even as we're wondering what's happening with our own planet, our robot probes are sending back spectacular new views of worlds elsewhere in the Solar System. The Cassini probe, in orbit around Saturn, continues to outperform the wildest expectations anyone had before the mission began. The high point for me still has to be the landing of Huygens - the little spacecraft carried by the Cassini mothership — on Titan and its sending back of color photos from the surface. But the amazing vistas of Saturn's other moons revealed by Cassini as it threads its way through the Saturnian realm have to be seen to be believed. Check out this amazing photo (BBC website), sent back last week, of the odd-shaped moon Hyperion.

It looks like a giant pumice stone! Researchers are still puzzling how Hyperion came to acquire its strange features: nothing else quite like it has ever been seen before.

Elsewhere, Japan's Hayabusa probe has been getting up close and personal with a half-mile-long, misshapen chunk of rock called Itokawa. This is the first asteroid from which it's hoped to return specimens for laboratory study. Go here (JAXA website) to see an image of this mini-world recently sent back by Hayabusa, together with suggested names for three features that have been identified on its surface. One of them is "Woomera Desert", the place in Australia where it's hoped the sample capsule carried by Hyabusa will parachute to Earth with its precious cargo in July 2007.


Monsters of the Deep

I don't know about you but I'm fascinated by mysterious and semi-mythical creatures. Is the Loch Ness Monster or Bigfoot real? Maybe - though I'd bet not. Are there any large animals still awaiting discovery anywhere? You bet! We're still finding them - new types of primate, shark, and so forth. We already knew that the giant squid was real. But no one had ever captured one live on film before in its natural habitat - hundreds of meters below the ocean surface. Now that's all changed. Every major TV station and newspaper last week carried pictures of an 8-meter-long Architeuthis snapped by Japanese researchers as it tussled with a baited line almost a kilometer down in waters off Japan's Ogasawara Islands. If you missed it, see the squid (National Geographic website) for yourself.

Several varieties of squid are known to exist even larger than the giant variety, including the "colossal" squid, Mesonychoteuthis hamiltoni, which is though to reach lengths of 20 to 25 meters. Read more about this creature, a dead specimen of which was netted in 2003 (BBC).


Correspondence

Remember last time we were talking about the discovery of a "tenth planet" - a new object in the Solar System that's bigger than Pluto? It's offical temporary name is 2003 UB313, though it's being popularly called Xena. The latest estimate is that its at least 20 percent more massive than Pluto and Cal Tech scientists have just confirmed that it has a moon. So, is it really Planet X? David Jordan writes from the UK:
"Just a brief observation about the tenth planet. When this came up on the news last week, I had a feeling of deja vu. It's like life on Mars: every few years someone — usually an American scientist with a good agent — rushes into print/camera with the great discovery. Then, closer scrutiny by his/her peers reveals a rather more sober explanation. Maybe someone is moving the goalposts on what constitutes a planet as opposed to a planetoid."
David's right to sound skeptical. Astronomers are having a heck of a time, following the discovery of several large Kuiper Belt objects of which Xena is the biggest, deciding what to call a planet. Two schools of thought have emerged. According to one, any object bigger than a certain size (say, that of Pluto) should be accorded planetary status. Xena would then be the tenth planet and we can expect eventually to find planets 11, 12, and so on, in the Kuiper Belt. According to the other school, Pluto should be demoted leaving only eight planets in the Solar System — the idea behind this being that an object is only a planet if it's the dominant body in its immediate neighborhood.

Finally, Charles ("Chuck") O'Dale writes from Canada to point out his intriguing website. Chuck is a retired engineer with a unique hobby — exploring all of North America's meteorite craters from his private airplane! See what he's been up to here.


Until next time,
Best wishes,
David Darling