The search for extraterrestrial intelligence just got a big boost, thanks to the introduction of a powerful new infrared telescope. In addition to scanning for pulses of infrared light, astronomers will use device to search for alien megastructures, such as Dyson Spheres.
As an idea, optical SETI has been around for a while. The suggestion that we might be able to detect alien messages in the infrared was first proposed by laser developer and Nobel laureate Charles Townes back in 1961. Efforts to find optical signals began more than a decade ago, but instruments capable of capturing pulses of infrared light have only recently been developed.
The new infrared detector, which is located at the Lick Observatory near San Jose, is called NIROSETI, which stands for near-infrared optical SETI.
As noted by University of California physicist Shelly Wright in UCSD News, "Infrared light would be an excellent means of interstellar communication." Though the signal would last for a mere billionth of a second, a pulse from a powerful infrared laser would outshine a star. If directed right at us (which it would have to be for us to detect it), an alien civilization could send us a series of repeated coded signals indicating its presence.
There are several advantages to using infrared light over radio signals or visible light. Radio signals are achingly weak and they disperse over vast interstellar distances. Contrast that with infrared light, which penetrates farther through gas and dust than visible light. Accordingly, the NIROSETI team will be able to extend the search to stars that are thousands, rather than hundreds, of light-years away. Also, less energy is required to send infrared light than visible light.
Excitingly, NIROSETI could also be used to search for Dyson Spheres. These hypothetical megastructures would envelop an entire star to reconstitute all the absorbed light into useful energy. But not all traces of the star would be extinguished. The stellar energy would be re-radiated back into space at considerably lower temperatures. Assuming all the visible light was absorbed by the shell, the signature of a pure Dyson Sphere would take on that of an infrared object.
"NIROSETI would detect Dyson Spheres that emitted large amounts of near-infrared light, especially if it varied in brightness," Geoff Marcy told io9. He's a member of the NIROSETI team and professor of astronomy at Berkeley.
Interestingly, the device could also be used to uncover astrophysical information as well.
"This is the first time Earthlings have looked at the universe at infrared wavelengths with nanosecond time scales," noted NIROSETI's Dan Werthimer in UCSD News. "The instrument could discover new astrophysical phenomena, or perhaps answer the question of whether we are alone."
Top image via From Quarks to Quasars; NIROSETI image: Laurie Hatch.