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David Darling's Newsletter #21


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May 25, 2004


Contents

1. Meanderings
2. Views from Mars, part 2
3. Bookends


1. Meanderings

Aside from my "newsflash" newsletter (#20) about the discovery of methane on Mars sent out last month, it's been quite a while since I was last in touch. Sorry about that, but I have a good excuse. I was rushing to meet the editorial deadline for my book on Teleportation, which will be in the bookstores in a few months time. This is a fascinating subject about which I want to chat with you more about in the coming weeks.

Following on from the last full issue (#19) on "Higher Dimensions," Roy Dutton wrote from Devon in England to point out that time is often taken to be the fourth dimension, so that we should regard the next higher dimension of space as the fifth dimension. This is a good point. To a physicist, used to talking about the four-dimensional space-time continuum, time really is the fourth dimension after the three of everyday space. Mathematicians tend to deal more in space dimensions alone and so are used to thinking in terms of four-dimensional cubes, spheres, and so on.

Also thanks to Michael Billnitzer of Perrysburg, Ohio, who got in touch to remind me that it was he who'd had one of the ideas I mentioned in #19. He'd called in while I was on the Coast-to-Coast AM radio show with George Noory (which, for those not familiar with it, runs through the middle of night in the U.S. and discusses all sorts of weird and wonderful subjects). Michael was wondering if the alleged shape-shifting that some UFOs are said to undergo could be due to rotation in the fourth dimension. I'm a bit of skeptic when it comes to UFOs but I thought it was a nifty idea.

In my Meanderings in Issue 19, I mentioned that of the following — having my name in lights on Broadway, encountering a giant crab on the south coast of England, meeting a Vulcan in Yellowstone Park, and being abducted by aliens — only one hadn't actually happened to me. The truth, as they say, is out there. I have had my name in lights on Broadway, but the Broadway in question was in downtown Portland, Oregon, where I was lecturing several years ago at the Schnitzer Concert Hall. I have encountered a giant crab on the south coast of England but I want to tell you about this in its proper place when I do an issue on cryptozoology. I have met a Vulcan in Yellowstone Park. Jill and I were staying at the Mammoth Hot Springs Hotel and in the morning decided to clear out our sinuses with a walk up to the sulfery springs themselves. Who should be there but Leonard Nimoy in full traditional Vulcan regalia filming for the first Star Trek movie! So, not only have I met a Vulcan but I know what his planet looks and smells like! I haven't, however, yet been abducted by aliens, unless it happened in my sleep or they erased my memory.

Finally, John Kirkley in commenting on my Mars methane newsflash, wondered what the impact might be of "unequivocally finding Martian life on the collective consciousness of we humans." Would it be something akin to the Copernican revolution, he mused, or more of a flash in the pan? We already know the answer, in a sense, from the reaction ) to the (overly optimistic, as it turned out) 1996 "announcement" of the discovery of Martian fossils. Worldwide headlines, Presidential mention, lots of excitement — for about a week! I think, as a race, we'd get used to Martian microbes quite quickly. Of course, it would transform astrobiology and energize our efforts to send more probes to Mars followed by a crewed mission. But we'd assimilate it without too much fuss. What would change everything would be the discovery of intelligent life, especially superior intelligent life, in the universe. I don't think we'd ever be the same again after that.

I hope you'll visit my "Worlds" website from time to time, or simply drop me a line to let me know how things are going. I may not always reply the same day, but I usually reply eventually!


2. Views from Mars, part 2

What a few months these have been on and around Mars, with both the Mars Exploration Rovers — Spirit and Opportunity — sending back bucket loads of pictures and data from the surface, and Mars Express returning some awesome pictures from orbit having hardly yet got into its scientific stride. And what a pity Beagle 2 couldn't make it a quartet of successes — particularly following the methane discovery, which Beagle would have been ideally suited to verify and further investigate.

As I write this, the Opportunity rover is poised, almost literally, on the edge of a sizeable, steep-sided crater called Endurance Crater, on the so-called Meridiani Planum. Spirit meanwhile is trundling its way across Gusev Crater to the distant Columbia Hills. On May 21, Spirit was still 680 meters (0.4 mile) from its first target at the western base of the hills, a spot informally called "West Spur." The mission team are estimating that Spirit will reach West Spur by June 1, 2004 (that's sol 146 — the 146th Martian day since the rover landed). It's expected to stay there for about a week to study the outcrops and rocks before moving on another 620 meters to a higher location dubbed "Lookout Point." Arrival at Lookout Point could happen around June 20, 2004 (sol 165). You can see an aerial view of the Columbia Hills region, and Spirit's projected path, by going to the JPL mission home page. And let's not forget, Mars Express in orbit above, which is only just at the start of its science mission and has already sent back some spectacular hi-res images. You can see many of these pictures at the ESA mission webpage.

There have been two huge discoveries by these combined probes. The rovers have found evidence, beyond all reasonable doubt, of past water at both locations. And Mars Express has confirmed what two ground-based telescope studies have shown: that there are small amounts of methane gas in the Martian atmosphere.

First, the water. Back at the start of March, NASA scientists announced that data from Opportunity, collected at an outcrop of rocks called "El Capitan," had convinced them that this location had once been drenched in liquid water. Steve Squyres, the principal science investigator, said: "We believe at this place on Mars for some period in time... this was a ground water environment that would have been suitable for life. That doesn't mean that life was there. We don't know that." Several lines of evidence pointed to past water: the physical appearance of the rocks, cross-bedding, small round beads nicknamed "blueberries," and high concentrations of salts. In fact, the rock was laden with salts, which on Earth happens when minerals precipitate out of water over time, and especially when the water evaporates. One of the salts the rover found is an iron sulfate called jarosite, which you'd normally associate with acid-rich lakes or the vicinity of hot springs. What does it all mean? Two main possibilities are being discussed. One is that volcanic eruptions threw out ash that formed layered rocks with lots of pores in them. Subsurface water then percolated through the pores, depositing salts. The other idea is that there was once a salty sea of water with currents and waves. As the water evaporated, salt settled out along with other sediments and built the layers we see today. I get the impression that the salty sea scenario is more popular but no one seems to have a good handle on how long the water was around for or when all this happened. Early to middle Martian history seems to be the best guess, which could put it anywhere from over 4 billion years ago to 3 or 3.5 billion years ago. The Spirit rover has also found evidence of past water in Gusev Crater, but not in sloshing-around amounts. It's found clues such as multiple coatings on rocks, and fractures filled with material that looks like it's been altered by water. The general impression is of small quantities of water, maybe underground. Still, water is water. And where there's water — or has been — there's hope for life.

Which brings me to the other big breakthrough of the past few months: the discovery of methane. Check out Newsletter #20 (which, like other past newsletters, is available on my website) for details of the three experiments — two on Earth-bound telescopes and one on Mars Express — that have contributed to this finding. As I mentioned in that announcement, there really is a very good chance that this methane is being produced by microbes in the soil. Methane can't survive in the Martian atmosphere for more than a few centuries, so what we're seeing today must either have been ejected in the fairly recent past or is being continually replenished. There's also a chance that it's been produced by volcanic activity. But you'd think if this were the case that the Themis experiment on Mars Odyssey would have found hot spots on the surface by now. We'll have to wait and see, but I'm in the life camp on this one at the moment.

We can look forward to plenty more extraordinary findings from Opportunity, Spirit, and Mars Express over the coming weeks and months. Both Mars rovers have had their missions extended beyond the nominal 3 months for a further 5 months, which takes them into the start of September (assuming their batteries and other vital systems hold out as the Red Planet gets further from the Sun). Mars Express has a nominal lifetime in orbit of one Martian year, or 687 days, which began last Christmas Day.


3. Bookends

My next book, The Universal Book of Mathematics, which is all about the most strange, puzzling, and entertaining aspects of this subject, goes on sale in August. You can find out about, and read samples from all my other books, by going to the home page of my website and clicking on any of the book covers. I was delighted to hear a few days ago from Richard Barrett in Australia who recently rescued a copy of Deep Time (1989) from a used bookstore in Melbourne. The title caught his eye because Richard has composed a piece also called Deep Time, which appears as one of the tracks that plays on the car radio in the computer game "Grand Theft Auto." I love those kind of strange connections!


Until next time,
Best wishes,
David Darling