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Beyond the Fermi Paradox --The Search for Extinct Alien Civilizations (VIEW Today's 'Galaxy' Stream)

 

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Contemplating extinct alien civilizations and the possibly of finding them and exploring their ruins to learn about them. Issac Arthur contemplates the possibility of bringing them back, and the conundrums that raises.

“As we improve our understanding of ancient Earth and the history of our solar system, perhaps we may someday uncover evidence that suggests the activity of another technological civilization right here in our neighborhood,” says Andrew Siemion, the director of Berkeley’s SETI Research Center.

 



One of the open questions of astrobiology is whether there is extant or extinct life elsewhere the Solar System. Astronomer Jason Wright at Penn State says that we are looking for microbial or, at best, unintelligent life, even though technological artifacts might be much easier to find.

Searches for alien artifacts in the Solar System typically presumes that the origins such artifacts would be from beyond our Solar System, even though life is known to have existed in the Solar System, on Earth, for eons.

But if a prior technological, perhaps spacefaring, species ever arose in the Solar System, it might have produced artifacts or other technosignatures that have survived to present day.

The origins and possible locations for technosignatures of such a prior indigenous technological species might have arisen on ancient Earth or another body, such as a pre-greenhouse Venus (image shown above NASA’s Pioneer Venus Orbiter took this false color image of Venus’ clouds ) or a wet Mars.

In the case of Venus, the arrival of its global greenhouse and potential resurfacing might have erased all evidence of its existence on the Venusian surface. In the case of Earth, erosion and, ultimately, plate tectonics may have erased most such evidence if the species lived a Gyr, a billion years, ago.

Wright suggests there could have been an explosion in life around the time of or after the Cambrian period, when a sudden wave of complex animals appeared, according to fossil records.

A cosmic catastrophe may have destroyed this early species, erasing all signs it ever existed and “forcing the biosphere to ‘start over’ with the few single-celled species that survived,” Wright writes.

We may have already seen technosignatures in geological record, but mistaken them for natural phenomena, Wright said. Or, the evidence may be long gone, erased from the surface by shifting tectonic plates.

“The Earth is quite efficient, on cosmic timescales, at destroying evidence of technology on its surface,” he writes in the paper.

Wright “correctly points out that there has existed ample opportunity for this to have occurred,” says Siemion.

Earth is the only place known to host intelligent life, which makes it a prime target for this kind of search. Life, after all, develops on planets with suitable environmental conditions, and Earth has provided just that.

Other indigenous technosignatures might be expected to be extremely old, limiting the places they might still be found to beneath the surfaces of Mars and the Moon, or in the outer Solar System.

Mars in particular may be well mapped by orbiters and rovers, but technological artifacts could be buried underneath its surface.

“For all we know, maybe Venus had cities all over it a billion years ago and now they’re gone,” Wright said.

The suggestion that artifacts from another intelligent species may be lying around the solar system is an old one, Wright said, first considered in the literature in the the 1890s.

“Once it felt like we had good maps of everything, once we went to Mars and mapped mars and mapped the moons of Jupiter, it all became a lot less unfamiliar,” Wright said. It makes sense that astronomers now look elsewhere, studying the subsurface oceans of Europa and Enceladus and listening for radio pings around stars light-years away. But the existence of technosignatures from an ancient species somewhere in time, Wright said, remains plausible.

A cosmic catastrophe may have destroyed this early species, erasing all signs it ever existed and “forcing the biosphere to ‘start over’ with the few single-celled species that survived,” Wright writes. We may have already seen technosignatures in geological record, but mistaken them for natural phenomena, Wright said. Or, the evidence may be long gone, erased from the surface by shifting tectonic plates.

“The Earth is quite efficient, on cosmic timescales, at destroying evidence of technology on its surface,” he writes in the paper.

If an “indigenous technological species” once existed somewhere in the solar system, why did they go extinct?

Wright suggests that an asteroid impact that led to mass extinction, a supernova closer than 30 light years, or a lethal burst of gamma rays. Or, perhaps the species, as some do, just died out, leaving behind hints of its history, and some corroded out of existence

The Daily Galaxy via The Daily Galaxy via The Atlantic and "Prior Indigenous Technological Species", arXiv:1704.07263 [astro-ph.EP] arxiv.org/abs/1704.07263

 

Comments

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The biological record on Earth is quite clear. It has taken the "tree of life" 5 billion years to produce an intelligent, technology producing species. That is a very long incubation period. There are no indications in Earth's biological record to suggest otherwise.

I suggest Issac consider the possibility that a journey within (meditation) will be far more fruitful in encountering an "alien intelligence". You project the need to do the inner journey into the outer situation in your SETI questing.

The following photos show many apparent artifacts found by Mars rover Curiosity:
1. https://www.flickr.com/photos/fossil_lin/21535456445/in/dateposted-public/
2. https://www.flickr.com/photos/fossil_lin/33836321242/in/dateposted-public/
3. https://www.flickr.com/photos/fossil_lin/21159227455/in/dateposted-public/
4. https://www.flickr.com/photos/fossil_lin/29160864896/in/dateposted-public/

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