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As nutty as it may seem to the uninitiated, the notion of looking for alien artifacts on our own Moon may finally be gaining mainstream scientific traction.
There are good reasons to seriously consider the possibility that at some point in the Earth-Moon system’s storied 4.5 billion year-old history, an alien intelligence may have passed through our solar system; leaving physical artifacts of their visits.
These artifacts would likely entail more than just alien space trash, and would arguably include evidence of alien scientific or industrial activity, such as extremely advanced lunar mining, energy generation; even technology related to lunar nearside Earth reconnaissance.
Or so says Paul Davies, a longtime SETI (Search for Extraterrestial Intelligence) researcher, physicist, and now Director of the Beyond Center at Arizona State University in Tempe.
At least one related paper on the subject is due to presented at the September meeting of the UK SETI Research Network, a group of mainstream British academicians. But even a decade ago, talk of alien lunar artifacts was mostly beyond the ken of anything remotely resembling the mainstream astronomical community.
With the success of crowdsourcing, citizen science initiatives such as SETI@home; Einstein@home; and Cosmology@home however, Davies and a handful of other serious scientific researchers are now advocating marrying crowdsourcing analysis with the images now being catalogued by NASA’s Lunar Reconnaissance Orbiter (LRO).
Since 2009, LRO has been measuring lunar landforms down to half meter resolution; in the process targeting more than 10,000 lunar sites and covering up to 90 percent of the lunar surface. The mission’s current success has resulted in a treasure trove of thousands of very high resolution images, almost all of which could be searched via an citizen science initiative.
Davies thinks the ideal lunar survey would not only include a search for optical anomalies but would go beyond the breadth of LRO’s own mission to include searches for evidence of alien lunar industrial activity.
“[Evidence of past] mining or quarrying could show up in gravimetry or magnetic surveys, even if an ancient mine was buried under the lunar regolith,” said Davies. “We could detect [alien] nuclear waste perhaps from a lunar satellite by looking for localized gamma ray sources from the lunar surface.”
A crowdsource lunar image analysis initiative might use Tomnod-type search software in the same way that volunteers were recruited to search satellite imaging for the missing Malaysian 777.
Davies says at some stage any search needs to be automated and use state-of-the-art software.
“In searching for artifacts, one is looking for ‘something fishy’,” said Davies. “But ‘fishiness’ requires a human decision in advance about a signature of artificiality. There are some simple examples, like right angle edges. But we have little idea what million year-old technology might look like.”
Yet Andrew Siemion, a research astronomer at the University of California at Berkeley, says citizen science projects involving image analysis are relatively straightforward to set up.
“Professional astronomers sometimes suffer from the tendency to discount anything other than our expected signal as instrumental noise or some kind of interference,” said Siemion. “When identifying the unexpected, the eye of an amateur citizen scientist can be just as effective, if not more so, than that of a conditioned professional.”
Volunteers sifting through images as part of a crowdsourcing effort, could make their efforts dual purpose. That is, they might look for orange pyroclastic rocks or even residual vulcanism at the same time they would look for artificial anomalies.
Davies says a search for lunar artifacts should be combined with a search for unusual geological features. However improbable, Davies says planetary scientists need to keep their eyes open for non-random anomalies; even ones on the moon and scrutinize their respective databases to “keep an eye out” for putative signatures of alien technology.
A 1995 academic paper by Ukrainian radio astronomer Alexey Arkhipov argues that only artifacts larger than one meter in size would be found on the lunar surface; with objects smaller than that buried by meters of regolith due to the lunar surface’s continual bombardment by micrometeorites.
Even so, Davies says, the moon is an attractive environment to search for artifacts because they would be preserved for much longer than on Earth (or Mars ). “On Earth, human artifacts get buried in centuries,” said Davies. “On the Moon it takes millions or tens of millions of years.”
However, Davies thinks the case for jettisoned material or junk is stronger than a gadget deliberately left for what might be an unknown and truly immense duration.
Arkhipov argued that the peak of the southern wall of the moon’s nearside crater “Malapert” would make a logical site for alien reconnaissance of Earth, since our planet can always be seen from there.
“Given that the moon is a big place, it pays to narrow the search by such educated guesses,” said Davies. “Lunar lava tubes would preserve artifacts and also provide an attractive location for equipment to be shielded from ultraviolet radiation and meteorites.”
When would alien probes have first arrived in our solar system?
Because Earth is only about a third of the age of the universe, habitable planets in the galaxy could thus have emerged at least 8 billion years ago, says Davies. So, he notes it’s likely that if alien technology ever entered our solar system, it happened a long time ago. Assuming that the number of technological extraterrestrial civilizations remain uniform over time, then Davies says it’s still arguable that our solar system has been visited at least once during that 8 billion year timeframe.
Thus, Davies reasons that the average expectation for a visit is of the order 4 billion years ago and later. But he says even a 100 million years ago is optimistically the most recent timeframe for their arrival. And to think they’ve been here since the dawn of recorded human civilization, he says, would be pretty much a statistical impossibility.
However you cut the numbers, says Davies, you would not expect “recent” visits.
In any event, Davies doesn’t expect that there have been any visits by flesh and blood entities and if there were, he reckons they would have moved on. In the event biological entities did travel to actually colonize a new planet, Davies says they would likely pick one without burgeoning life forms, due to difficulties co-habitating with any existing biology.
“My position is that biological intelligence is but a transitory phase in the evolution of intelligence in the universe,” said Davies. “Why dispatch fragile biological entities on a hazardous journey across the vastness of space when almost all the intellectual heavy lifting, let alone the physical grunt work, will be done by designed systems?”
And Davies says if such a system happened to enter our solar system, for reasons we cannot even imagine, it may either “stay, go, or multiply.”
Of course, in science fiction, the most famous alien artifact was the enigmatic monolith envisioned in Arthur C. Clarke’s “2001: A Space Odyssey.” In the novel and subsequent film, the monolith appears to reactivate after being found just a few meters under the lunar regolith.
SETI searchers have long considered the possibility that dormant alien probes may have been sent to our solar system to wait as silent sentinels before our own technology wakes up to their possible presence. SETI researchers have even considered the possibility of beaming radio beacons to the Earth-Sun gravitational Lagrange points in hopes of “awakening” such unseen probes. That is, if they are out there.
In the last 40 years, before the advent of digital photon counters on telescopes, there were two relatively cursory searches within both the Earth-Sun and Earth-Moon Lagrange points, using comparatively small aperture optical telescopes at Kitt Peak, Arizona and Leuschner Observatory in California. Both failed to detect any such non-human artificial objects.
John Gertz, president of the California-based FIRSST (Foundation for Investing in Research on SETI Science and Technology) initiative, suggests conducting a radio search for a beacon within our own inner solar system that would have been activated at the probe’s first detection of Earth’s own electromagnetic leakage. He thinks it would now be broadcasting now at very low wattage and would have no message, other than the implied one, “I am here; and I am artificial.”
Likely smaller than a car, but larger than a grapefruit, Gertz says the payload, a virtual Encylopedia Galactica — or their civilization’s complete history and knowledge — could be stored on a thumb drive which we would literally have to physically retrieve.
This, of course, assumes that the designers of such probes would have an innate desire to bare their alien souls to an emerging technology like ours.
“Physical encoding is a very efficient way of transmitting very large amounts of information from point-to-point,” said Siemion. “So, it is entirely possible that an advanced civilization might choose to disseminate large amounts of information via encoded physical artifacts.”
There may even be more than one such probe waiting for us.
“There is no reason to believe that only one civilization has sent a probe; there may be a variety of probes out there,” said Gertz.
So, why not look?
“I advocate searching all free searchable databases just for the hell of it,” said Davies.
Quelle: Forbes
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