Search for extraterrestrial intelligence extends to near-infrared optical signals

Astronomers have expanded the search for extraterrestrial intelligence into a new realm with detectors tuned to infrared light. The idea was first proposed by Charles Townes, the late UC Berkeley scientist whose contributions to the development of lasers led to a Nobel Prize.
Pulses from a powerful near-infrared laser could outshine a star, if only for a billionth of a second. Interstellar gas and dust is almost transparent to near-infrared, so these signals can be seen from greater distances. It also takes less energy to send the same amount of information using infrared signals than it would with visible light.
Scientists have searched for radio signals for more than 50 years and expanded their search to the optical realm more than a decade ago. But instruments capable of capturing pulses of infrared light have only recently become available.
“We had to wait for technology to catch up,” said Shelley Wright, an Assistant Professor of Physics at the University of California, San Diego who led the development of the new instrument while at the University of Toronto’s Dunlap Institute for Astronomy & Astrophysics.
The new instrument, called NIROSETI (near-infrared optical SETI), will also gather more information than previous optical detectors by recording levels of light over time so that patterns can be analyzed to for potential signs of other civilizations.
NIROSETI has been installed at the University of California’s Lick Observatory on Mt. Hamilton east of San Jose and saw first light on March 15. Lick Observatory has been the site of several previous SETI searches, including an instrument to look in the optical realm, which Wright built as an undergraduate student at UC Santa Cruz.