Radio telescopes monitor the sky at the Allen Telescope Array in California. Finding a signal from a distant civilization is one way we could experience first contact with ET. (SETI Institute Photo)
Is it a multimedia art project? Or a rehearsal for alien contact? Let’s call it both: Researchers specializing in the search for extraterrestrial intelligence, or SETI, are working with a media artist to stage the receipt of an interstellar message — and a global effort to decode the message.
The metaphorical curtain rises on May 24, when ESA’s ExoMars Trace Gas Orbiter transmits an encoded radio message from Martian orbit to Earth at 19:00 UTC / noon PDT.
CHIME consists of four metal "half-pipes", each one 100 meters long. Image Credit: CHIME/Andre Renard, Dunlap Institute.
In 2017, the Canadian Hydrogen Intensity Mapping Experiment (CHIME) began to gather light from the Universe to address some of the biggest questions and astrophysics and cosmology. Located at the Dominion Radio Astrophysical Observatory (DRAO) in British Columbia, this interferometric radio telescope has been a game-changer for studying Fast Radio Bursts (FRBs), which remain one of the most mysterious cosmic mysteries facing astronomers today.
In the near future, CHIME will be getting an expansion that will help it more accurately identify where FRBs are coming from. This will consist of a new radio telescope outrigger located at the SETI Institute’s Hat Creek Radio Observatory (HCRO), new outriggers near Princeton, British Columbia, and at the Green Bank Observatory in West Virginia. These will work with the main CHIME telescope to localize CHIME-detected FRBs precisely in the night sky.
omposite image of the SKA combining all elements in South Africa and Australia. CreditL SKAO
In Australia and South Africa, there are a series of radio telescopes that will be soon joined by a number of newly-constructed facilities to form the Square Kilometer Array (SKA). Once established, the SKA will have a collecting area that measures a million square meters (close to 2 million square yards). It will also be 50 times more sensitive than any radio telescope currently in operation, and be able to conduct surveys ten thousand times faster.
During a historic meeting that took place on June 29th, 2021, the member states that make up the SKAO Council voted to commence construction. By the late 2020s, when it’s expected to gather its first light, the array will consist of thousands of dishes and up to a million low-frequency antennas. These will enable it to conduct all kinds of scientific operations, from scanning the earliest periods in the Universe to searching for extraterrestrial intelligence (SETI).
RATAN-600 radio telescope located in Northern Caucasus in the Karachaevo-Circassian Republic of Russian Federation. . Credit: SAO RAS.
We’re not saying its aliens, but this could be the most enticing SETI-related signal from space since the famous “Wow! Signal” in 1977.
Over the weekend, interstellar expert Paul Gilster broke the news that “a strong signal” was detected by Russian radio astronomers from the region around the star HD 164595. This signal has attracted enough attention that two prominent SETI observatories are quickly making follow-up observations. Alan Boyle reports in Geekwire that the Allen Telescope Array in California has already been observing the star system and the Boquete Optical SETI Observatory in Panama will make an attempt this evening, if the weather is clear.
Doug Vakoch, the President of METI International (Messaging Extraterrestrial Intelligence) told Universe Today via email that the Allen Telescope Array has already completed its initial reconnaissance of HD 164595, “with no indications of alien technologies at radio frequencies.”
“The first step in following up a putative SETI signal is to look at the same frequency where it was first detected,” Vakoch said, and with the nil detection from the ATA, “now it’s time to search other parts of the electromagnetic spectrum.”
Vakoch said METI International will be observing HD 164595 for brief laser pulses from the Boquete Optical SETI Observatory in Panama as soon as weather permits.
“It looks like the Boquete Observatory will be hit by heavy thundershowers late this afternoon and into this evening,” he said, “so we’ll likely need to wait to observe until another night. Once the evening sky is clear in Boquete, we’ll have about an hour to observe in the direction of the constellation Hercules shortly after sunset.”
The signal from HD 164595 was originally detected on May 15, 2015, by the Russian Academy of Science-operated RATAN-600 radio telescope in Zelenchukskaya, Russia. It is located about 95 light years from Earth in the constellation Hercules. The signal had a wavelength of 2.7 cm, with an estimated amplitude of 750 mJy.
Gilster wrote on his Centauri Dreams website that the researchers have worked out the strength of the signal and that if “it came from an isotropic beacon, it would be of a power possible only for a Kardashev Type II civilization,” which means a civilization capable of harnessing the energy of the entire star, and developing something like a Dyson sphere surrounding the star, and transfer all the energy to the planet.
Freeman Dyson theorized that eventually, a civilization would be able to build a megastructure around its star to capture all its energy. Credit: SentientDevelopments.com
If the beam was narrow and sent directly to our Solar System, the researchers say it would be of a power available to a Kardashev Type I civilization, a type of civilization more advanced than us that is able to harness the full amount of solar power it receives from its star.
Of course, like any other signal, such as the recent study of the dimming light curve of KIC 8462852 (Tabby’s Star) that is still being researched, it is possible the signal comes from other “natural” events such microlensing of a background source or even comets as been proposed for both Tabby’s Star or the “Wow! Signal.”
The SETI website explains that narrow-band signals – ones that are only a few Hertz wide or less – are the mark of a purposely built transmitter. “Natural cosmic noisemakers, such as pulsars, quasars, and the turbulent, thin interstellar gas of our own Milky Way, do not make radio signals that are this narrow. The static from these objects is spread all across the dial.”
Update: A member of the SETI@Home team posted a note online that they were “unimpressed” with the paper from the Russian radio astronomers. “Because the receivers used were making broad band measurements, there’s really nothing about this “signal” that would distinguish it from a natural radio transient (stellar flare, active galactic nucleus, microlensing of a background source, etc.) There’s also nothing that could distinguish it from a satellite passing through the telescope field of view. All in all, it’s relatively uninteresting from a SETI standpoint.”
So, this detection might not be as exciting as originally reported. Also SETI senior astronomer Seth Shostak has now weighed in on the topic, also with measured skepticism on the excitement, with a post about this event on the SETI website.
What has probably fueled interest in this signal is the striking similarities between the star and our Sun. HD 164595 is a star just a tad smaller than our Sun (0.99 solar masses), with the exact same metallicity. The age of the star has been estimated at 6.3 billion years it is already known to have at least one planet, HD 164595 b, a Neptune-sized world that orbits the star every 40 days. And as we’ve seen with data from the Kepler spacecraft, with the detection of one planet comes the very high probability that more planets could orbit this star.
Why the Russian team has only made this detection public now is unclear and it may have only come out now because the team wrote a paper to be discussed at an upcoming SETI committee meeting during the 67th International Astronautical Congress in Guadalajara, Mexico, on Tuesday, September 27.
As Gilster wrote, “No one is claiming that this is the work of an extraterrestrial civilization, but it is certainly worth further study.”
One of the 42 dishes in the Allen Telescope Array that searches for signals from space. Credit: Seth Shostak / SETI Institute.
“We either caught something shortly after an event like two planets crashing together or alien intelligence,” said Dr. Gerald Harp, senior scientist at the SETI Institute in Mountain View, California, referring to the baffling light variations seen by the Kepler Observatory in the star KIC 8462852 .
And he and a team from the Institute are working hard at this moment to determine which of the two it is.
Gerald Harp of the SETI Institute is involved in gathering and studying data from the mysterious Kepler star. Credit: SETI Institute
Beginning last Friday (Oct. 16), the Institute’s Allen Telescope Array (ATA) was taken off its normal survey schedule and instead focused on KIC 8462852, one of the 150,000-plus stars studied by NASA’s Kepler Mission to detect Earth-sized exoplanets orbiting distant stars.. The array of 42 dishes comprises a fully automated system that can run day and night, alerting staff whenever an unusual or interesting signal has been detected.
A swarm of comets has been proposed to explain the erratic and non-repeating light variations seen in the star located nearly 1,500 light years from Earth in the constellation Cygnus the Swan. But no one really seems satisfied with the explanation, and the chances that we’d catch a huge event like a comet breakup or planetary collision in the short time the star has been under observation seems unlikely. Collisions also generate dust. Warmed by the star, that dust would glow in infrared light, but none beyond what’s expected has been detected.
The Allen Telescope Array (ATA) is a “Large Number of Small Dishes” (LNSD) array designed to be highly effective for simultaneous surveys undertaken for SETI projects (Search for Extraterrestrial Intelligence) at centimeter wavelengths. Credit: Seth Shostak / SETI Institute
The ATA picks up radio frequencies in the microwave range from 1-10 gigahertz. For comparison, your kitchen microwave oven produces microwaves at around 2 gigahertz. Although Harp couldn’t reveal the team’s results yet — that will come soon when a paper is submitted in few weeks in a science journal — he did share the excitement of a the hunt in a phone interview Tuesday.
The array normally looks for a very narrow wave or specific frequency when hunting for potential “ET” signals. But not this time.
“This is a special target,” said Harp. “We’re using the scope to look at transmissions that would produce excess power over a range of wavelengths.” Perhaps from a potential alien power source? Maybe. Harp believes the star’s peculiar, a-periodic light variations seen by Kepler are “probably natural and definitely worth looking at” but considers an intelligent source a possibility, however remote.
This artist concept illustrates how two large, planet-sized objects could collide to create clumps of material in orbit around a star. They’d also create a lot of dust, which would glow in infrared light, something not seen around the Kepler star. Credit: NASA/JPL-Caltech/T. Pyle (SSC)
During our conversation, he emphasized how special the light variations from the star were, adding how the “big gob” of material orbiting KIC (stands for Kepler Input Catalog) 8462852 is unusual in that it’s “clumped”. “We expect it to spread into a ring,” he said.
AAVSO chart of KIC 8462852. Click to enlarge or go to the website to make your own customized version. Credit: AAVSO
Meanwhile, the American Association of Variable Star Observers (AAVSO) published an Alert Notice this week requesting amateurs and professional astronomers around the world to immediately begin observing KIC 8462852 now through the end of the current observing season. To locate the star, you can either use the charts provided in our previous story or go to the AAVSO site and type in KIC 8462852 in the “Pick a Star” box to create a chart of your own.
I’m a variable star observer, so naturally I thought of variables with irregular fluctuations in light when I first heard about this stellar mystery. Time to talk to an expert. According to Elizabeth Waagen, senior technical assistant for science operations at the AAVSO, KIC 8462852 is different.
“Based on the information so far, it doesn’t seem to fit the criteria for an irregular variable,” said Waagen in a phone interview this morning. “It’s doesn’t add up.”
She encouraged an open mind. “It’s a big puzzle, so we sent out the notice,” referring to the alert described above.
All quite exciting, and I’m as eager as you to see the published results on the signals, which Harp said would appear or link from the SETI website soon. Stay tuned …
The Allen Telescope Array is the first radio telescope designed specifically for SETI Photo by Colby Gutierrez-Kraybill
Since it was founded in 1984, the SETI (Search for Extraterrestrial Intelligence) Institute in Mountain View, California, has been a principal American venue for scientific efforts to discover evidence of extraterrestrial civilizations. In mid-November, the institute sponsored a conference, “Communicating across the Cosmos”, on the problems of devising and understanding messages from other worlds. The conference drew 17 speakers from numerous disciplines, including linguistics, anthropology, archeology, mathematics, cognitive science, philosophy, radio astronomy, and art.
This is the second of four installments of a report on the conference. Today, we’ll look at the SETI Institute’s current efforts to find an extraterrestrial message, and some of their future plans. If they find something, just how much information can we expect to receive? How much can we send?
The idea of using radio to listen for messages from extraterrestrials is as old as radio itself. Radio pioneers Nikola Tesla and Guglielmo Marconi both listened for signals from the planet Mars early in the 20th century. The first to listen for messages from the stars was radio astronomer Frank Drake in 1960. Until recently though, SETI projects have been limited and sporadic. That began to change in 2007 when the SETI Institute’s Allen Telescope Array (ATA) started observations.
Consisting of 42 small dishes, the ATA is the first radio telescope in the world designed specifically for SETI. The SETI search is currently managed by Jon Richards, an engineer who is an expert on both the system’s hardware and software. He spoke at the conference about the project. The ATA is currently used for SETI research twelve hours out of each day, from 7 pm to 7 am. During the day, the site is operated by Stanford Research International to perform more conventional astronomical studies. When used for such observations, the dishes can function together as an interferometer, generating images of celestial radio sources. To minimize radio interference from human activities, the telescope is sited a six hour drive north of the SETI Institute at the remote Hat Creek Observatory in the Cascade Mountains of Northern California.
The ATA can detect signals over the range from 1 to 10 GHz. The researchers use several strategies to tell potential ETI signals apart from naturally occurring radio sources in space, and human-made terrestrial interference. Radio emissions from natural sources are smeared over a broad range of frequencies. Artificial signals designed for communication typically pack all of their energy into a very narrow frequency band. To detect such signals, the ATA can resolve frequency differences down to just 1 Hz.
When a radio source is moving with respect to the receiver, it appears to change in frequency. This phenomenon is called the Doppler effect. Because an alien planet and the Earth would be moving in relation to one another, a genuine ETI signal would exhibit the Doppler effect. A source of terrestrial interference that’s fixed to the Earth wouldn’t. If the beam of the telescope is shifted away from the target, a genuine alien signal emanating from a distant point in space would disappear, reappearing when the beam was shifted back. A signal due to local interference wouldn’t.
This illustration of the Doppler effect shows the change of wavelength caused by the motion of the source. Credit: ARM.
The ATA is designed to perform these tests automatically whenever it detects a potential candidate signal. To make sure, it repeats the second test five times. If a signal passes the tests, the operator is automatically sent an e-mail, and the candidate signal is entered into a database. Periodically, as a test, the telescope is programed to point in the direction of one of the two Voyager spacecraft. Because these spacecraft are hurtling through deep space beyond the orbit of Neptune, their signals mimic the properties expected from an alien transmission. So far, all the e-mails received have been generated by such tests, and by false alarms. The fateful e-mail announcing the successful detection of an extraterrestrial signal has not yet been sent.
Richards explained that the ATA’s most recent project has been to listen to more than one hundred Earth-like planets discovered by the Kepler space telescope between 2009 and 2012. Next year the ATA’s antenna feeds will get an upgrade that will increase their upper frequency limit to 15 GHz and greatly increase their sensitivity. Both ground-based and Kepler studies have identified numerous Earth-like planets at habitable distances from small dim red dwarf stars. A systematic search of these stars is planned next. If the SETI Institute can find the funding they hope eventually to expand the ATA to 350 dishes.
According to astronomer Jill Tartar, the retired director of the SETI Institute’s Center for SETI Research, the institute is hoping to become involved in a much larger international project; the Square Kilometer Array (SKA). When it begins operations in 2020, the SKA is planned to be the world’s largest radio telescope. It will consist of several thousand dishes and other receivers giving it a radio signal collecting area of one square kilometer. The advantage of having more collecting area is that the telescope is sensitive to fainter signals. If funding allows it to be built in the way currently planned, it will be capable of training multiple simultaneous beams at the sky, some of which Tartar said might be used to mount a continuously ongoing SETI search.
The planned Square Kilometer Array will be the world’s largest radio telescope when it begins operations in 2018 Swinburne Astronomy Productions for SKA Project Development Office
Suppose we did find something. What sort of reply could we send? How much do we have the technological capability to send, if we wanted to? Back in 1974, in the first demonstration of the capacity for interstellar messaging, the Arecibo radio telescope transmitted a mere 210 bytes, and took 3 minutes to do it. The message consisted of a human stick figure and a few other crude symbols and diagrams. Because this primitive effort is still the most well-known example of interstellar radio messaging, prepare yourself for a stunning surprise. According to SETI Institute radio astronomer Seth Shostak, using broadband microwave radio, we could send them the Library of Congress (consisting of 17 million books) in 3 days, and the contents of the World Wide Web (as of 2008) in a comparable time.
Using the shorter optical wavelengths of a laser beam and optical broadband, we could send either one in 20 minutes. Since the extraterrestrials might tune in at any time, we would need to send the transmission over and over again many times. Although our transmissions could be sent in only days or minutes, they would, of course, still take decades or centuries to traverse the light years. This transmission capability presents a stunning opportunity. We can send anything. We can send everything. Could it really be that someday, beings from Tau Ceti will peruse your Facebook page?
So what can we expect from the aliens? Any message we might receive, Seth Shostak thought, would be of one of two possible sorts. A civilization already aware of our existence, he believed, would send us a huge message, rich in information content. This is because even if technological civilizations are fairly common in the galaxy the nearest one might be tens, hundreds, or thousands of light years away. Radio messages traveling at the speed of light will take that long to cross those distances, and decades or centuries will elapse between query and response. If we are contacted, Shostak really does think that we should send the aliens the entire content of the World Wide Web. Civilizations further away than 70 light years from Earth probably wouldn’t know that we exist, because radio signals from Earth haven’t reached them yet. Shostak didn’t think that civilizations would waste precious transmitting time and energy bombarding planets with petabytes of information if they didn’t already know that there was a technological civilization there. Worlds that weren’t known to harbor a civilization, Shostak speculated, might get put on a long list of potentially habitable planets to which the aliens might periodically send a brief “ping” hoping to get a response.
A petabyte of gibberish contains as much information as a petabyte of our world’s greatest art and literature (or tackiest YouTube videos). A petabyte of our world’s greatest art and literature is gibberish to a being who can’t understand it. We could send the aliens truly stunning amounts of information, but can we find some way to ensure that they will understand its meaning? Could we hope to understand an alien message sent to us, or would all those petabytes be for naught? In the next installment, we’ll learn that we face daunting problems.
S. J. Dick (1996), The Biological Universe: The Twentieth_Century Extraterrestrial Life Debate and the Limits of Science, Cambridge University Press, Cambridge, UK.
SETI, the Search for Extraterrestrial Intelligence suffered a big blow in April of this year when the primary alien search engine –the Allen Telescope Array (ATA) in northern California — was put into “hibernation” due to lack of funds. But now you can help get the ATA back online through a crowdsourcing effort called SETIstars. Similar to fundraising efforts like KickStarter, SETIstars is working to raise enough money to bring the telescope array online again and provide operating costs for at least one year. The goal is to raise $200,000.
As of this writing, nearly $30,000 has been raised already.
While the ATA is not the only radio telescope that can be used for SETI searches, it was the observatory that was primarily used for that task. The funding crisis occured when state and the National Science Foundation contributions were significantly cut.
SETIstars is an initiative by the SETI Institute to rally support from the community to help fund the SETI Institute’s operations and that of the Allen Telescope Array. SETIstars has clearly defined fundraising goals, and will recognize supporters and contributors to the SETI Institute — both financial and non-financial.
“We are starting with a simple site with a clear mandate: raise funds from the community to help bring the ATA back on line,” says the SETIstars website. “But this is just the beginning…Bringing the ATA back online is a critical first step. However, sustaining operations is also of vital importance. SETIstars will be a rallying point for future community engagement and fundraising efforts.”
Here’s your chance to allow SETI scientists to start listening for signals from space again, especially in the region in space where Kepler has found a boatload of exoplanets. Your donations are tax free (in the US) since SETI is a nonprofit institution. International donors should contact their government for information on tax deductions for charitable gifts to U.S. based charities.
SETI, the Search for Extraterrestrial Intelligence has suffered a big blow. The primary alien search engine –the Allen Telescope Array (ATA) in northern California — has been shut down due to budget woes. In a letter last week, the CEO of the SETI Institute, Tom Pierson told donors that in the ATA has been put into “hibernation,” — a safe mode of sorts, where “the equipment is unavailable for normal observations and is being maintained in a safe state by a significantly reduced staff.”
The ATA has been in hibernation since April 15, with the equipment put in a safe configuration so that it stays ready to be turned back on should the SETI Institute find new sources of funding.
While the ATA is not the only radio telescope that can be used for SETI searches, it was the observatory that was primarily used for that task, and now SETI researchers will have to borrow time on telescopes where “competition for observing time can be fierce or piggyback their searches on other ongoing observations,” according to John Matson, writing for Scientific American.
The ATA was operating with 42 antennas, and was scheduled to expand gradually to 350 six-meter radio antennas to listen for possible radio emissions from any faraway civilizations that might exist elsewhere in the galaxy. But after the first $50 million phase was completed in 2007, additions to the array were delayed due to lack of funding.
NASA had funded some of the early SETI projects, but Congress canceled any NASA contributions in 1993. The nonprofit SETI Institute, founded in 1984, relies mainly on private donations to support its research. Microsoft co-founder Paul Allen, had contributed $25 million to the first phase, with donations and grants funding the rest.
According to astronomer Franck Marchis, who works for the SETI Institute and the University of California, Berkeley – which is responsible for operating the ATA, “the financial state of the observatory degraded significantly over the past 2 years with the loss of various sources of funding (NSF, California state) at UC Berkeley” forcing UC Berkeley to withdraw from the SETI project. And, as Marchis wrote on his blog, “because the project is mainly funded through private donors, the economic recession had a huge impact and delayed significantly the expansion of the array impacting the overall project.”
In his letter, Pierson said that NSF funding has been reduced to approximately one-tenth of what it formerly gave to SETI. “This is compounded by growing State of California budget shortfalls that have severely reduced the amount of state funds available to the Radio Astronomy Lab.”
ATA operations cost about $1.5 million per year, Pierson said, and the SETI science campaign at ATA costs another $1 million annually.
Pierson said that the SETI Institute has been working for more than two years to find additional funding, such as providing assistance to the US Air Force in tracking orbital debris. The SETI Institute is also currently working on a fundraising campaign to raise $5 million so that the ATA can be used to focus on the potentially habitable planets found by the Kepler telescope.
For anyone who is interested in donating SETI, and in particular the ATA and their search of signals from the Kepler database of planets, see this website.
