In 1960 during the early days of the search for extraterrestrial intelligence, theoretical physicist Freeman Dyson, who died last month, wrote an article titled "Search for Artificial Stellar Sources of Infrared Radiation" for the journal Science. He posited that "if extraterrestrial intelligent beings exist and have reached a high level of technical development, one by-product of their energy metabolism is likely to be the large-scale conversion of starlight into far-infrared radiation." One way to achieve that, he suggested, was by building an "artificial biosphere surrounding one star." And with that seed, the science fiction (science fact?) idea of an alien megastructure has grown, even making its way onto an episode of Star Trek: The Next Generation. From Elizabeth Howell's article in Space.com:

One of Dyson's daughters sent the physicist a videotape of a 1987 episode of "Star Trek: The Next Generation" called "Relics," Dyson said. The plot follows a distress call heard by the famous USS Enterprise starship; fans of the series may recall this as a crossover episode with "Star Trek: The Original Series" star Montgomery "Scotty" Scott (played by James Doohan).

The crew warps in space to the source of the call and discovers an immense Dyson sphere — which is indeed portrayed as a solid spherical object — surrounding a star. If we were to place this sphere in our own solar system, it would be so large that it would extend almost as far as the orbit of Venus, according to "Star Trek" fan site Memory Alpha.

One way to determine whether distant worlds may be home to extraterrestrials is to seek out the presence of biosignatures, molecules that indicate the existence of past or present life, in the exoplanet's atmosphere. (The chemical composition of the atmosphere affects its color spectra, observable with telescopes.) According to new MIT research, one biosignature may be a stinky, poisonous gas found in swamps, bogs, and even some animals' bowels. From MIT:

MIT researchers have found that phosphine is produced by... anaerobic organisms, such as bacteria and microbes, that don’t require oxygen to thrive. The team found that phosphine cannot be produced in any other way except by these extreme, oxygen-averse organisms, making phosphine a pure biosignature — a sign of life (at least of a certain kind).

In a paper recently published in the journal Astrobiology, the researchers report that if phosphine were produced in quantities similar to methane on Earth, the gas would generate a signature pattern of light in a planet’s atmosphere. This pattern would be clear enough to detect from as far as 16 light years away by a telescope such as the planned James Webb Space Telescope. If phosphine is detected from a rocky planet, it would be an unmistakable sign of extraterrestrial life.

“Here on Earth, oxygen is a really impressive sign of life,” says lead author Clara Sousa-Silva, a research scientist in MIT’s Department of Earth, Atmospheric and Planetary Sciences. “But other things besides life make oxygen too. It’s important to consider stranger molecules that might not be made as often, but if you do find them on another planet, there’s only one explanation.”

Through a collaboration with NASA and the SETI Institute, Girl Scouts can now earn badges in space science, from astronomy to the search for extraterrestrial intelligence.

“Part of science literacy is understanding our place in the big world, in the solar system, in the universe," Pamela Harman, the director of education at the SETI Institute, told Air & Space Magazine. "Once we realize that, I think it’s easier to think about protecting our planet.”

From Air & Space:

Girl Scout cadettes (grades 6-8) can earn the space science researcher badge by investigating properties of light and observing the night sky; seniors (grades 9-10) can obtain the space science expert badge by classifying stars and studying their life cycles; and ambassadors (grades 11-12) seeking the space science master badge will explore exoplanets through activities such as designing a habitat for an alien world.

Read the rest

The classic approach to the scientific search for extraterrestrial intelligence (SETI) is to scan the skies for radio transmissions from intelligent civilizations. While we definitely won't hear anything if we don't listen, SETI Institute senior astronomer Seth Shostak urges us to also keep our eyes (and sensors) peeled for another kind of alien technosignature: alien megastructures, "massive engineering works that an advanced society has constructed somewhere in space." We haven't found one yet but the possibility made headlines several years ago when a team of astronomers led by Tabetha Boyajian described a star that periodically dims in a very odd way. Shostak writes:

One explanation was that the star was surrounded by a Dyson sphere. The idea, proposed years ago by physicist Freeman Dyson, is that really advanced aliens would construct a gargantuan, spherical swarm of solar panels in orbit beyond their own planet — sort of the way you might cup your hands around a candle to collect the heat. The swarm would gather enough starlight to energize the aliens’ souped-up lifestyles, and could sometimes get in the way of light from the star, causing it to intermittently dim as seen from afar.

That explanation for Tabby’s star seems less likely today. Astronomical measurements show that it gets redder when it dims, suggesting that it’s surrounded by naturally produced dust, not a gargantuan group of light collectors.

But it’s reasonable to believe that Dyson spheres exist somewhere. In the past, astronomers looked for clues to such massive engineering projects by trawling star catalogs for systems that show an excess of infrared light — produced by the warm backside of the panels.

One distant galaxy, one "very unusual repeating signal." But it's never aliens.

...a very unusual repeating signal, coming from the same source about 1.5 billion light years away. Such an event has only been reported once before, by a different telescope. ... The CHIME observatory, located in British Columbia's Okanagan Valley, consists of four 100-metre-long, semi-cylindrical antennas, which scan the entire northern sky each day.

Is there life out there? That's one of the mind-boggling questions that the SETI Institute explores through its scientific research, all the while inspiring our own curiosity and sense of wonder about our place in the universe. SETI stands for the Search for Extraterrestrial Intelligence and the official mission of the organization, founded in 1984, "is to explore, understand and explain the origin and nature of life in the universe and the evolution of intelligence." Support their efforts with these far out new t-shirts from the SETI Institute's Chop Shop Store.

Above, the iconic SETI Logo tee. Below, a graphic expression of SETI pioneer Frank Drake's "Drake Equation" used to estimate the number of technological civilizations that could have developed in our galaxy. And lastly, a design honoring the scientists whose pioneering work underpins the search for extraterrestrial intelligence: Galileo Galilei, Johannes Kepler, Carl Sagan, Frank Drake, and Jill Tarter.

SETI Institute t-shirts (Chop Shop Store)

Read the rest

With NASA's InSight spacecraft scheduled to land on Mars today, it's fun to watch this vintage ABC News Australia segment from 1962: "Is there life on other planets?"

One of my favorite responses: "I hope not. Because they'd be frozen to death."

(via r/ObscureMedia) Read the rest

A feasibility study in the Astrophysical Journal explains how a powerful laser on an Earth mountaintop, focused through a huge telescope, could shine a light of infrared radiation that would be detectable up to 20,000 light years away. While some scientists are concerned about alerting extraterrestrials to our presence, I agree with something said to me by Ann Druyan -- co-writer of Cosmos and many other works with her husband Carl Sagan -- when we were working on the Voyager Golden Record: 40th Anniversary Edition: It's rather cynical, she explained, to think that a extraterrestrial civilization advanced enough to notice us and make the long trip to Earth would be so emotionally stunted as to purposely destroy us upon arrival. From MIT News:

The findings suggest that if a high-powered 1- to 2-megawatt laser were focused through a massive 30- to 45-meter telescope and aimed out into space, the combination would produce a beam of infrared radiation strong enough to stand out from the sun’s energy.

Such a signal could be detectable by alien astronomers performing a cursory survey of our section of the Milky Way — especially if those astronomers live in nearby systems, such as around Proxima Centauri, the nearest star to Earth, or TRAPPIST-1, a star about 40 light-years away that hosts seven exoplanets, three of which are potentially habitable. If the signal is spotted from either of these nearby systems, the study finds, the same megawatt laser could be used to send a brief message in the form of pulses similar to Morse code.

In 1960, my friend Frank Drake launched Project Ozma, the first modern scientific search for extraterrestrial intelligence (SETI). Frank used the National Radio Astronomy Observatory (image above) in Green Bank, West Virginia to listen for interstellar radio transmissions that might be a signature of ETs. Nearly 60 years and countless scans later, we still haven't heard anything. Why? Space is big. Massive. In a 2010 paper, the SETI Institute's Jill Tarter and her colleagues described their ongoing calculations of a “cosmic haystack" where we're searching for an extraterrestrial needle.

"If you build a mathematical model, the amount of searching that we've done in 50 years (as of 2008) is equivalent to scooping one 8-ounce glass out of the Earth's ocean, looking and seeing if you caught a fish," Tarter told NPR. "No, no fish in that glass? Well, I don't think you're going to conclude that there are no fish in the ocean. You just haven't searched very well yet. That's where we are."

Now, Penn State astronomer Jason Wright and colleagues have refined the "cosmic haystack" model to include additional factors involving likely frequencies and bandwidth along with the latest large SETI searches. Even still, they "conclude that the fraction of it searched to date is also very small: similar to the ratio of the volume of a large hot tub or small swimming pool to that of the Earth's ocean."

From Science News:

Converting the volume to liters for the sake of analogy, the researchers concluded that SETI has covered the equivalent of 7,700 liters out of 1.335

Researchers from extraterrestrial research initiative Breakthrough Listen, the SETI Institute, and UC Berkeley used machine learning to detect mysterious repeating radio bursts from a galaxy 3 billion light years from Earth. As of now, the source of the fast radio bursts (FRBs) is unknown and, yes, the bursts "could be the signatures of technology developed by extraterrestrial intelligent life," according to the scientists. From the SETI Institute:

In August of 2017, the Listen science team at the University of California, Berkeley SETI Research Center observed FRB 121102 for five hours, using digital instrumentation at the GBT. Combing through 400 TB of data, they reported (in a paper [pdf] led by Berkeley SETI postdoctoral researcher Vishal Gajjar, recently accepted for publication in the Astrophysical Journal) a total of 21 bursts. All were seen within one hour, suggesting that the source alternates between periods of quiescence and frenzied activity.

Now, (UC Berkeley doctoral student Gerry) Zhang and collaborators have developed a new machine learning algorithm, and reanalyzed the 2017 GBT dataset, finding an additional 72 bursts that were not detected originally...

Additional FRB research may provide clues about whether or not they are signatures of extraterrestrial technology.

More at UC Berkeley news: "AI helps track down mysterious cosmic radio bursts" Read the rest

Remember the fantastic attention experiment in which you have to count the times the basketball is passed? (If you don't know it, watch the video before reading the rest of this post.)

In a recent paper in the scientific journal Acta Astronautica, University of Cadiz psychologists suggest that like the gorilla experiment, "selective attention" based on our preconceptions about possible extraterrestrials and how they may communicate may cause us to overlook evidence of their existence. Over at the SETI Institute blog, BB pal and astronomer Seth Shostak likens their argument to the gorilla experiment and counters that right now, the best thing to do is what we know how to do. And that's scanning the skies with antennae listening for signals:

It would be heavy-duty hubris to claim that we have considered every possibility in our efforts to find aliens. We’ve certainly been myopic in the past. During the nineteenth century, European physicists suggested we could establish contact with Martians by turning gas lanterns in the direction of the Red Planet. The plan was hopeless, but not because the scientists were ignoring other possibilities. They simply didn’t know about radio or much about Mars, and proposed a reasonable experiment given the science understanding of the time.

Sure, our preconceived notions of what would be good evidence of aliens — including radio signals, flashing lasers, or megastructures — might be blinding us to clues that, like nitrogen in the air, are all around us and yet overlooked. But to quote Dirty Harry, “a man’s got to know his limitations.”

On March 22, Institute for the Future, the nonprofit thinktank where I'm a researcher, is hosting an event celebrating the Voyager Golden Record at our Palo Alto, California offices/gallery! Joining me in conversation will be legendary astronomer Frank Drake, the father of the scientific search for extraterrestrial intelligence and technical director of the original Voyager Record in 1977. Tickets are $10 and RSVP is required: "The Voyager Golden Record: Celebrating a Journey Through Space and Time" I hope to see you there! Here's the full announcement...

IFTF's The Future Presents... "The Voyager Golden Record: Celebrating a Journey Through Space and Time" Thursday, March 22, 2018, 5:30 to 7:30pm 201 Hamilton Ave. Palo Alto, CA RSVP is required.

Please join Institute for the Future for a reception celebrating the Voyager Golden Record, the iconic message for extraterrestrials, launched into space by NASA in 1977 and released on vinyl for the first time in the 2017 Grammy-winning boxed set, “Voyager Golden Record: 40th Anniversary Edition,” created by IFTF researcher David Pescovitz, Timothy Daly, and Lawrence Azerrad. At this special event, Pescovitz, also a co-editor of Boing Boing, will be host a conversation with legendary astronomer Frank Drake, the father of the Search for Extraterrestrial Intelligence (SETI) and technical director of the original Voyager Record.

Forty years ago, NASA launched two Voyager spacecraft on a grand tour of the solar system and into the mysteries of interstellar space. Attached to each of these probes is a golden phonograph record containing Earth's greatest music from myriad peoples and eras, natural sounds, spoken greetings in dozens of human languages, and more than 100 encoded images that depict who, and what, we are.

Is there anybody out there? If we don't listen for the answer, we certainly won't hear it. Over at the Planetary Society, Jason Davis posted an excellent survey of the past, present, and future of the search for extraterrestrial intelligence. It begins in 1959 with Giuseppe Cocconi and Philip Morrison's historic paper "Searching for Interstellar Communications" and Frank Drake's Project Ozma, the first scientific SETI search:

One year later, the National Academy of Sciences hosted an invitation-only meeting at Green Bank to discuss how to go about conducting further SETI research. The eclectic, interdisciplinary group included Drake, Cocconi, Morrison, the biochemist Melvin Calvin (who won the Nobel Prize in Chemistry during the meeting), Bernard Oliver, who was the vice president of research and development at Hewlett-Packard, the young Carl Sagan, and the scientist John Lilly, who had recently published a controversial book arguing dolphins were an intelligent species.

With a nod to Lilly's book, the participants dubbed themselves "The Order of the Dolphin." One product of the meeting was the Drake equation, which attempts to predict the number of advanced civilizations in the Milky Way able to contact Earth. The equation includes variables such as average star formation rate, the number of habitable planets per star, and the number of planets where intelligent life could evolve.

For the rest of the 1960s, SETI research remained mostly dormant, aside from a few searches in the Soviet Union. Starting in 1971, two Project Ozma follow-ups named Ozpa and Ozma II used bigger dishes and listened to more stars.

Stephen Canfield and his colleagues at WeTransfer curated a stunning online experience inspired by the Voyager Golden Record, the iconic message for extraterrestrials launched into space on a phonograph record 40 years ago. My friends Tim Daly and Lawrence Azerrad and I co-produced the first ever vinyl release of the Voyager Record this year and we were honored to help with WeTransfer's effort, titled A Message from Earth.

A Message To Earth includes newly-commissioned images, art, sound, and words from the likes of Gilles Peterson, Wanda Díaz Merced, Aspen Matis, S U R V I V E, Lawrence Krauss, Fatima Al Qadiri, and Oneohtrix Point Never. It's a beautiful, non-linear exhibition of creative work that embodies the sense of hope, optimism, and goodwill instilled by the original Voyager Record.

The exhibition's intention is to relay a message of goodwill and encourage further exploration while raising awareness and funding for Astronomers without Borders, the Carl Sagan Institute at Cornell University, and the SETI Institute. WeTransfer is providing $10,000 grants to each institution to initiate public donations, and the project will be commemorated in a $15 limited edition zine with 100% of generated revenues going to the non-profits above.

Far out.

Here are the contents of A Message From Earth:

Preface: A comic of illustrations by Sophy Hollington telling the story and brief history of the original Golden Record.

1. Greetings: Wanda Díaz Merced, a blind astronomer who uses sonification to study interstellar events, presents a study of stars as heard on earth - with a selection of images curated by NASA's Rebecca Roth.

FRB 121102, a fast radio burst signal first picked up in 2012, was just observed emitting many new bursts of energy. Scientists from SETI and Breakthrough Listen were both very excited by the new findings. Read the rest

In 1971, astronomer Frank Drake, the father of the search for extraterrestrial intelligence, drew a map pinpointing Earth in our galaxy. That diagram, a "pulsar map," was etched on a plaque designed by Frank and Carl Sagan and first carried into space in 1972 by the Pioneer 10 and 11 spacecraft. In 1977, the pulsar map would appear again etched on the covers of the golden records affixed to the the Voyager probes. These days, Frank's original pencil drawing of the map is stored in an old tomato box at his house. (In fact, Frank kindly allowed us to scan it for our book included in our new Voyager Golden Record vinyl box set!) Over at National Geographic, Nadia Drake, one of my favorite science journalists who also happens to be Frank's daughter, tells the fascinating story of this iconic piece of cosmic cartography. From National Geographic:

The question was, how do you create such a map in units that an extraterrestrial might understand?

...To my dad, the answer was obvious: pulsars. Discovered in 1967 by Jocelyn Bell Burnell, these dense husks of expired stars were perfect blazes in both space and time.

For starters, pulsars are incredibly long-lived, staying active for tens of millions to multiple billions of years.

Also, each pulsar is unique. They spin almost unbelievably fast, and they emit pulses of electromagnetic radiation like lighthouses. By timing those pulses, astronomers can determine a pulsar’s spin rate to a ridiculous degree of accuracy, and no two are alike.

In 1977 radio astronomers at the Big Ear space telescope, searching for signs of extraterrestrial life, came across a signal that wasn't just odd, it was unbelievably strong! The signal, broadcast at at 1420.456 MHz, radiated from the direction of the constellation Sagittarius, and lasted just seventy-two seconds. When researcher Jerry R. Ehman came across the signal he wrote "Wow!" on the print out.

Antonio Paris, a professor of astronomy at Florida's St. Petersburg College, thinks he's figured out the source -- a pair of recently discovered comets!

Everything about the Wow! signal created huge interest. The frequency it was found on correlates strongly with the 'hydrogen line' and was believed to be a most-likely frequency to for Aliens to use when communicating with us. The intensity and sharp build-up/fall off of the signal led researchers to believe it came from a fixed point in the sky. Antonio Paris believes the signal was a sign of two comets, unidentified at the time of the recording, passing in front of the Big Ear.

Via New Scientist:

Comets release a lot of hydrogen as they swing around the sun. This happens because ultraviolet light breaks up their frozen water, creating a cloud of the gas extending millions of kilometres out from the comet itself.

If the comets were passing in front of the Big Ear in 1977, they would have generated an apparently short-lived signal, as the telescope (now dismantled) had a fixed field of view. Searching that same area – as subsequent radio telescopes did – wouldn’t show anything.