One of Earth’s leading alien hunters has predicted that intelligent alien life forms will be found within two dozen years - after our telescopes have scanned two million star systems.
The prediction comes from Seth Shostak of the SETI Institute - one of Earth’s leading alien-hunting organisations, which uses an array of 42 radio telescopes to scan star systems NASA telescopes have pinpointed as likely to host life.
Shostak thinks that by the year 2040, telescopes will have scanned enough star systems to find E.T. - not just alien microbes, or planets likely to host life, but radio signals from space.
"I think we'll find E.T. within two dozen years using these sorts of experiments," Shostak said this week in a NASA talk at Stanford University.
"Instead of looking at a few thousand star systems, which is the tally so far, we will have looked at maybe a million star systems,” Shostak says. "A million might be the right number to find something. One in five stars has at least one planet where life might spring up. That's a fantastically large percentage. That means in our galaxy, there's on the order of tens of billions of Earth-like worlds."
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Seth Shostak has warned that any such signals could be “disruptive” to our society, bringing new technologies - or could be incomprehensible.
“We could become privy to knowledge that would otherwise remain unknown until developed by our descendants centuries or more in the future, he said last year, “While this manna from the skies could be profoundly disruptive, you can't argue that ignorance is blissfully preferable. It's not.”
Shostak also warned that it is entirely possible that we might not be able to understand such transmissions - “ the meaning of the message might eternally elude us”.
The SETI project has searched for alien life for 50 years - but has been met by silence. But NASA’s Kepler mission has provided SETI’s alien-hunters with known planets to aim at. The organisation’s telescopes are also significantly more powerful than previous technology.
The Allen Telescope Array, in Mountain View, California is a significant upgrade from telescopes that previously “listened” for radio signals - listening to radio frequencies which have never been observed before.
Previous telescopes tended to focus on a narrow band of signals - like listening to radio stations one by one - whereas the Allen array can search tens of millions of radio channels at once, across frequencies that are naturally “quiet”.
Since December 2011, the telescopes - funded by donations from supporters such as Contact star Jodie Foster - have been scanning on planets found by NASA’s Kepler telescope, and in particular those believed to be “habitable.”
Kepler “looks” at a field of 150,000 stars, looking for the tell-tale dips in brightness caused by planets passing in front of the stars.
It has found 2,740 planet candidates with estimated sizes from Mercury to larger than Jupiter. the ATA is focusing on Earth-like worlds in the “habitable zone” around stars - where liquid water could exist.
Jill Tarter, the Director of the Center for SETI Research at the SETI Institute said when the ATA began its scans of planets picked out by Kepler as likely candidates, "For the first time, we can point our telescopes at stars, and know that those stars actually host planetary systems - including at least one that begins to approximate an Earth analog in the habitable zone around its host star. That's the type of world that might be home to a civilization capable of building radio transmitters."
"In SETI, as with all research, preconceived notions such as habitable zones could be barriers to discovery," Tarter says. "So, with sufficient future funding from our donors, it's our intention to examine all of the planetary systems found by Kepler."