Sen—The search for extraterrestrial life (SETI) received a huge boost this week, when a new program to search for signals was announced.
Named Breakthrough Listen, this renewed effort will incorporate radio telescopes in both hemispheres which will scan the skies over a broader range of radio frequencies than ever before. The project will include use of the U.S. National Science Foundation’s 100 meter Green Bank Telescope (GBT) based in West Virginia, and the 64 meter Parkes radio telescope based in Australia.
Part of the Breakthrough Prize Foundation effort, the Breakthrough Listen contract announced on July 20 will provide $2 million dollars a year over the next 10 years to Green Bank to allow for the international effort. Compare this to the $1.5 million a year funding needed to operate the Allen Telescope Array (ATA) at Hat Creek. The ATA project went on a temporary hiatus when NSF funds dried up during the 2011 U.S. government shutdown.
“Beginning early next year, approximately 20 per cent of the annual observing time on the GBT will be dedicated to searching a staggering number of stars and galaxies for signs of intelligent radio signals,” said National Radio Astronomy Observatory (NRAO) director Tony Beasley in a recent press release. “We are delighted to play such a vital role in hopefully answering one of the most compelling questions in all of science and philosophy: are we alone in the Universe?”
The $100 million dollar Breakthrough Listen project was unveiled at a Royal Society meeting in London Monday, promoted by such science luminaries as physicist Professor Stephen Hawking.
“We believe that life arose spontaneously on Earth,” Hawking said during the Monday press release. “So in an infinite universe, there must be other occurrences of life.”
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Video from the press conference announcing the Breakthrough Listen initiative to search for E.T.
The plan will not only systematically search the one million stars nearest to Earth, but it will scan the galactic plane of the Milky Way and nearby galaxies for signs of extraterrestrial intelligence. The Parkes and GBT radio telescopes are sensitive enough that they would be able detect aircraft radar transmitting from a planet orbiting the nearest 1,000 stars, which equates to about a radius of 70 light years. Some of the powerful radars used in World War II would’ve been easily detected at this distance.
Breakthrough Listen will also involve a concerted effort using optical searches as well. To this end, the project will utilize the Automated Planet Finder Telescope at the Lick Observatory in California to watch for any laser flashes that E.T. might be sending our way to try and get our attention.
The dome housing the Automated Planetfinder Telescope. Image credit: Oleg Alexandrov/Public Domain.
All of the data generated by Breakthrough Listen will be available to the public as well. To this end, the project will also team with the popular SETI@Home project in the search for signals. Started in 1999, SETI@Home is a crowdsourced project that uses a computer’s idle time to sift through data looking for signals that may have been generated by extraterrestrial intelligence.
Software and computing power has changed vastly since Frank Drake ushered in the era of the modern SETI search with Project Ozma in 1960. Ozma looked at just two nearby Sun-like stars: Tau Ceti and Epsilon Eridani. In the next 60 years, SETI has been an on- and off- affair, mainly at the whim of budgetary constraints and precious observing time allotted to it on radio telescopes.
Frank Drake also proposed a method to calculate how many civilizations might exist currently in our galaxy for us to talk to. Known as the Drake Equation, it factors in:
The yearly rate of star production in the galaxy;
The fraction of stars that have planets;
The fraction of those planets suitable for life;
The fraction those planets where life actually arises;
The fraction of those instances where intelligent life arises;
The fraction of those civilizations that develop the capability to communicate across space;
And finally, the last value L is the length of time said civilization is active.
SETI has yet to turn up compelling detections of extraterrestrial intelligence, although there have been some tantalizing moments. The Wow! signal was detected by the Big Ear radio telescope project working out of Ohio State University in 1977. Lasting for 72 seconds, the Wow! signal was a radio burst detected by Jerry R. Ehman during a SETI search on Aug. 15, 1977. Terrestrial and satellite interference was ruled out, and tantalizingly, the signal came from along the plane of the Milky Way, right where you might expect it to be. Was it a from natural source, or perhaps, a distant artificial transmitter that was gravitationally lensed long enough for Earthbound receivers to pick it up? The area in the constellation of Sagittarius that the signal originated from has been scanned repeatedly in the years to follow, but has never repeated.
In 1950, physicist Enrico Fermi even proposed what’s become known of as Fermi’s Paradox: if intelligent life is common, then where are they? Many solutions have been proposed over the years: maybe the final factor of L in Frank Drake’s famous equation noting the longevity of a transmitting civilization is so small that there is currently no one nearby to talk to. Maybe there’s a universal ‘Prime Directive’ (think Star Trek) in place, and we haven’t merited contact yet. Or maybe civilizations become ‘radio quiet’ as they outgrow technological adolescence and become more efficient. Or maybe bacterial life is common, but radio telescope-building iPhone-carrying intelligent apes like ourselves are rare.
The Green Bank Radio Telescope, part of the new Breakthrough Listen campaign. Image credit: NRAD/AUI/NSF
Or maybe everyone’s listening and no one is transmitting. It’s tough to tell how typical we are with just a statistical sample set of one. NASA is searching for life in our Solar System as well, and discovery of microbial life on Mars or in the subterranean seas of Europa would have far-reaching implications.
Breakthrough Listen will also spearhead a possible Breakthrough Message project as well to perhaps carry out a crowd-sourced message to be transmitted to space.
Or perhaps, the first detections may come from the hunt for exoplanets. For example, the detection of the spectral signature of chlorophyll on an exoplanet—a chemical molecule that, on Earth, is only created by life—would present a strong case that something interesting is occurring on a far off world. We may soon also have the capability to detect ‘extraterrestrial light pollution’ on the nighttime side of exoplanets given off by the glow of E.T.'s cities.
We live in an amazing era for sure, and the Breakthrough Listen project may deliver the greatest scientific discovery of our lifetimes.