On Pi Day, March 14 2015, a team of astronomers expanded the search for extraterrestrial intelligence into a new realm when they made their first observation, known as “first-light,” with a ground-breaking instrument.
While most searches for a signal from an advanced alien civilization have been conducted with radio telescopes, the new instrument, called NIROSETI, is the first capable of detecting extremely short, extremely bright pulses of infrared light.
“Infrared light is an excellent means of interstellar communication,” said Shelley Wright, who led the development of the new instrument while at the University of Toronto’s Dunlap Institute for Astronomy & Astrophysicsand is now an assistant professor of physics at the University of California, San Diego. Interstellar gas and dust is almost transparent to near infrared, so these signals can be seen from greater distances than visible light.
NIROSETI, or Near InfraRed Optical Search for Extra-terrestrial Intelligence, looks for short pulses based on the thinking that an advanced alien civilization attempting to communicate with us would send pulses rather than a continuous signal; if the same amount of energy was put into a continuous signal or an extremely short pulse, the pulse would be much brighter. In fact, a laser signal a billionth of a second long could outshine the Sun.
According to Wright, the idea dates back decades, and scientists had expanded their search for a signal from ET to the optical realm more than a decade ago.
But instruments capable of capturing pulses of infrared light have only recently become feasible. “We had to wait for technology to catch up,” Wright said. “I spent eight years waiting and watching as new technology emerged.”
Then, while Wright was still at the Dunlap Institute, a new generation of detector technology arrived. She and Dunlap Fellow Jérome Maire — who played a key role in developing the new instrument — tested detectors and found that they could turn the concept into reality.
“It was exciting,” said Maire, “to solve the technological challenge of building the first instrument capable of detecting an infrared signal a billionth of a second long.”
The team at the Dunlap Institute also included U of T undergraduate student Patrick Dorval and Elliot Meyer, a U of T graduate student.
NIROSETI has been installed at the University of California’s Lick Observatory, the site of several previous SETI searches including an optical instrument which Wright built as an undergraduate student at UC Santa Cruz under the direction of Remington Stone, the director of operations at Lick at that time. Dan Werthimer and Richard Treffers of UC Berkeley designed that first optical instrument. All three are playing critical roles in the new search.
NIROSETI could uncover new information about the physical Universe as well. “This is the first time Earthlings have looked at the Universe at infrared wavelengths with nanosecond time scales,” Werthimer said. “The instrument could discover new astrophysical phenomena, or perhaps answer the question of whether we are alone.”
The group also includes SETI pioneer Frank Drake of the SETI Institute and UC Santa Cruz who serves as a senior advisor to both past and future projects and is an active observer at the telescope.
Drake pointed out several additional advantages to a search in this new realm. “The signals are so strong that we only need a small telescope to receive them. Smaller telescopes can offer more observational time, and that is good because we need to search many stars for a chance of success.” he said. The receivers are also much more affordable that those used on radio telescopes.
“There is only one downside: the extraterrestrials would need to be transmitting their signals in our direction,” Drake said, though he sees a positive side to that limitation. “If we get a signal from someone who’s aiming for us, it could mean there’s altruism in the universe. I like that idea. If they want to be friendly, that’s who we will find.”
The NIROSETI team also includes Geoffrey Marcy and Andrew Siemion from UC Berkeley. Shelley Wright is also a member of the Center for Astrophysics and Space Sciences at UC San Diego. Richard Treffers is now at Starman Systems. Funding for the project comes from the generous support of Bill and Susan Bloomfield
With files from Susan Brown.