RT
2011-09-12 02:01:52 UTC
Interesting.
http://www.newscientist.com/article/mg21128294.100-scour-earth-for-traces-of-intelligent-aliens.html
Scour Earth for traces of intelligent aliens
If smart aliens exist, they may have visited Earth millions of years ago
and left signs of their technological prowess that should be cheap and easy
for us to detect.
So says astrophysicist Paul Davies of Arizona State University in Tempe.
Traditionally, the search for extraterrestrial intelligence (SETI) has
focused on listening for deliberate dispatches in radio signals. But in 50
years of searching, this costly approach has drawn a blank.
So Davies suggests scouring our own planet, even our cells, on the off-chance
that aliens visited and did what amounts to scrawling "We were here" on the
walls. "We can answer the question 'Are we alone?' without picking up
messages," he says. "We may see indirect evidence of alien technology based
on the footprint it leaves."
If aliens did come to our cosmic neighbourhood, it was probably hundreds of
millions of years ago. Any "footprints" would have to last for eons to be
detected by us. That means a manufactured slab of rock in the style of
2001: A Space Odyssey would be a poor candidate: it would erode,
or at least get buried before we came to notice it.
But detritus from industry, such as mining, might last. Former mines on the
Earth, the moon or asteroids could show up in geological surveys, even if
they have filled in or eroded since the aliens left, says Davies.
Nuclear waste is another possibility. Davies suggests we search for
plutonium-244. The element occurs naturally on Earth in trace amounts only
and has a half-life of 80 million years. So substantial deposits would be a
sign of alien nuclear technology.
This echoes a suggestion by Frank Drake of the SETI Institute in California
that aliens might have used radioactive materials to mark the location of a
message.
Aliens may even have left deliberate messages in our DNA, Davies says. Most
DNA includes long sequences that seem to serve no biological function.
Aliens may have embedded code in this "junk DNA" a sequence of prime
numbers as in the movie Contact, say to signal their existence to us.
Microbiologist Steve Benner of the Foundation for Applied Molecular Evolution
in Gainesville, Florida, reckons such a message would get deleted pretty
quickly. "Paul is being a little too extravagant here," he says. "He
overestimated the robustness of non-functional DNA."
...
Regarding that last part - mitochondrial Eve anyone?
http://www.newscientist.com/article/mg21128294.100-scour-earth-for-traces-of-intelligent-aliens.html
Scour Earth for traces of intelligent aliens
If smart aliens exist, they may have visited Earth millions of years ago
and left signs of their technological prowess that should be cheap and easy
for us to detect.
So says astrophysicist Paul Davies of Arizona State University in Tempe.
Traditionally, the search for extraterrestrial intelligence (SETI) has
focused on listening for deliberate dispatches in radio signals. But in 50
years of searching, this costly approach has drawn a blank.
So Davies suggests scouring our own planet, even our cells, on the off-chance
that aliens visited and did what amounts to scrawling "We were here" on the
walls. "We can answer the question 'Are we alone?' without picking up
messages," he says. "We may see indirect evidence of alien technology based
on the footprint it leaves."
If aliens did come to our cosmic neighbourhood, it was probably hundreds of
millions of years ago. Any "footprints" would have to last for eons to be
detected by us. That means a manufactured slab of rock in the style of
2001: A Space Odyssey would be a poor candidate: it would erode,
or at least get buried before we came to notice it.
But detritus from industry, such as mining, might last. Former mines on the
Earth, the moon or asteroids could show up in geological surveys, even if
they have filled in or eroded since the aliens left, says Davies.
Nuclear waste is another possibility. Davies suggests we search for
plutonium-244. The element occurs naturally on Earth in trace amounts only
and has a half-life of 80 million years. So substantial deposits would be a
sign of alien nuclear technology.
This echoes a suggestion by Frank Drake of the SETI Institute in California
that aliens might have used radioactive materials to mark the location of a
message.
Aliens may even have left deliberate messages in our DNA, Davies says. Most
DNA includes long sequences that seem to serve no biological function.
Aliens may have embedded code in this "junk DNA" a sequence of prime
numbers as in the movie Contact, say to signal their existence to us.
Microbiologist Steve Benner of the Foundation for Applied Molecular Evolution
in Gainesville, Florida, reckons such a message would get deleted pretty
quickly. "Paul is being a little too extravagant here," he says. "He
overestimated the robustness of non-functional DNA."
...
Regarding that last part - mitochondrial Eve anyone?