However, the scientific community has since announced that the signal is unlikely to be anything other than the result of natural phenomena. This was also the conclusion reached by Amir Siraj and Prof. Abraham Loeb of Harvard University after they conducted a probability assessment on BLC1. Like the vast majority of candidate radio signals discovered to date, this one appears to be just the forces of nature saying hello.
There’s a powerful scene in the movie “Contact” (one of my favs) where lead character Ellie Arroway is sitting among an array of telescopes and hears the first alien signal – an ominous pulse – received by humanity. She races back to the control center where the array is pointed off target and then back to verify the signal. Contact is made. Shortly after, a message is found in the signal and we’ve confirmed the existence of alien life!
Ellie Arroway was inspired by a real-life pillar of the SETI community, Dr. Jill Tarter. I had the privilege of interviewing Jill Tarter last year and asked about that scene. She laughed saying “There’s not a lot of sitting around with headphones on. It’s not really that simple.” When it comes to analyzing signals from the stars for alien life, distinguishing a potential alien message from the noise of our own planet is quite complicated.
Excitingly, we’re watching that analysis play out right now as a signal which appears to originate from our closest neighbour star, Proxima Centauri, was recently detected by the Breakthrough Listen Project
Back in April, we reported on how a collaboration between the Chinese Academy of Sciences, the Breakthrough Listen Initiative, and the SETI Institute planned to use the new Five-hundred-meter Aperture radio Telescope (FAST) to search for signs of extraterrestrial life. We now caught up with another of the project scientists to flesh out some more details of their observational plans and what observations they hope to make in the future.
In the past five years, the project has made two major data releases (in the June of 2019 and February of 2020) and announced that it found no signs of alien transmissions from the 1,327 nearest star systems. But thanks to an analytical breakthrough recently proposed by researchers from the University of Manchester, it looks as though Breakthrough Listen’s search efforts could be expanded by a factor of more than 200!
In July of 2015, Breakthrough Initiatives announced that it was embarking on a ten-year initiative to conduct the largest Search for Extraterrestrial Intelligence (SETI) to date. This initiative was aptly named Breakthrough Listen, which combines state-of-the-art software and data obtained by premier observatories around the world to look for signs of extraterrestrial technological activity (aka. technosignatures).
Last week (Friday. Feb. 14th), the Breakthrough Listen Initiative released about 2 petabytes of optical and radio data that they have accumulated over the past four years. This is the second data release by the non-profit effort (as part of Breakthrough Initiatives) and the public is once again invited to search through the data for possible signs of extraterrestrial communications.
This week, the non-profit research organization Breakthrough Listen announced that it was entering into a partnership with scientists from the NASA Transiting Exoplanet Survey Satellite (TESS) mission. This new collaboration will direct the resources of the former with data and expertise of the latter to the search for extra-terrestrial intelligence (SETI) like never before!
In 2016, Russian-Israeli billionaire Yuri Milner launched Breakthrough Initiatives, a massive non-profit organization dedicated to the search for extra-terrestrial intelligence (SETI). A key part of their efforts to find evidence of intelligent life is Breakthrough Listen, a $100 million program that is currently conducting a survey of one million of the nearest stars and the 100 nearest galaxies.
In keeping with their commitment to making the results of their surveys available to the public, the Listen team recently submitted two papers to leading astrophysical journals. These papers describe the analysis of Listen’s first three years of radio observations which resulted in a petabyte of radio and optical data, the single largest release of SETI data in the history of the field.
Since that time, multiple surveys have been conducted to determine the true nature of this asteroid, which have included studies of its composition to Breakthrough Listen‘s proposal to listen to it for signs of radio transmissions. And according to the latest findings, it seems that ‘Oumuamua may actually be more icy than previously thought (thus indicated that it is a comet) and is not an alien spacecraft as some had hoped.
As they indicate in their study, the team relied on information from the ESO’s Very Large Telescope in Chile and the William Herschel Telescope in La Palma. Using these instruments, they were able to obtain spectra from sunlight reflected off of ‘Oumuamua within 48 hours of the discovery. This revealed vital information about the composition of the object, and pointed towards it being icy rather than rocky. As Fitzsimmons explained in op-ed piece in The Conversation:
“Our data revealed its surface was red in visible light but appeared more neutral or grey in infra-red light. Previous laboratory experiments have shown this is the kind of reading you’d expect from a surface made of comet ices and dust that had been exposed to interstellar space for millions or billions of years. High-energy particles called cosmic rays dry out the surface by removing the ices. These particles also drive chemical reactions in the remaining material to form a crust of chemically organic (carbon-based) compounds.”
These findings not only addressed a long-standing question about ‘Oumuamua true nature, it also addresses the mystery of why the object did not experience outgassing as it neared our Sun. Typically, comets experience sublimation as they get closer to a star, which results in the formation of a gaseous envelope (aka. “halo”). The presence of an outer layer of carbon-rich material would explain why this didn’t happen ‘Oumuamua.
They further conclude that the red layer of material could be the result of its interstellar journey. As Fitzsommons explained, “another study using the Gemini North telescope in Hawaii showed its color is similar to some ‘trans-Neptunian objects’ orbiting in the outskirts of our solar system, whose surfaces may have been similarly transformed.” This red coloring is due to the presence of tholins, which form when organic molecules like methane are exposed to ultra-violet radiation.
Similarly, another enduring mystery about this object was resolved thanks to the recent efforts of Breakthrough Listen. As part of Breakthrough Initiatives’ attempts to explore the Universe and search for signs of Extra-Terrestrial Intelligence (ETI), this project recently conducted a survey of ‘Oumuamua to determine if there were any signs of radio communications coming from it.
While previous studies had all indicated that the object was natural in origin, this survey was more about validating the sophisticated instruments that Listen relies upon. The observation campaign began on Wednesday, December 13th, at 3:00 pm EST (12:00 PST) using the Robert C. Byrd Greenbank Radio Telescope, the world’s premiere single-dish radio telescope located in West Virginia.
The observations period was divided into four “epochs” (based on the object’s rotational period), the first of which ran from 3:45 pm to 9:45 pm ET (12:45 pm to 6:45 pm PST) on Dec 13th, and last for ten hours. During this time, the observation team monitored ‘Oumuamua across four radio bands, ranging from the 1 to 12 GHz bands. In addition to calibrating the instrument, the survey accumulated 90 terabytes of raw data over after observing ‘Oumuamua itself for two hours.
“It is great to see data pouring in from observations of this novel and interesting source. Our team is excited to see what additional observations and analyses will reveal”.
So far, no signals have been detected, but the analysis is far from complete. This is being conducted by Listen’s “turboSETI” pipeline, which combs the data for narrow bandwidth signals that are drifting in frequency. This consists of filtering out interference signals from human sources, then matching the rate at which signals drift relative to the expected drift caused by ‘Oumuamua’s own motion.
In so doing, the software attempts to identify any signals that might be coming from ‘Oumuamua itself. So far, data from the S-band receiver (frequencies ranging from 1.7 to 2.6 GHz) has been processed, and analysis of the remaining three bands – which corresponds to receivers L, X, and C is ongoing. But at the moment, the results seem to indicate that ‘Oumuamua is indeed a natural object – and an interstellar comet to boot.
This is certainly bad news for those who were hoping that ‘Oumuamua might be a massive cylinder-shaped generation ship or some alien space probe sent to communicate with the whales! I guess first contact – and hence, proof we are NOT alone in the Universe – is something we’ll have to wait a little longer for.
Dr. Emilio Enriquez is a Post Doc at the Berkeley SETI Research Center and a member of the Breakthrough Listen Initiative (http://seti.berkeley.edu/listen/). Emilio is the lead author of two recent SETI Research Center publications about Ross 128 b, the nearby exoplanet that researchers feel may have conditions that are conducive to life.
His expertise is in modelling of physical processes in galaxies, such as gas accretion onto galaxies, star formation, stellar feedback, gas accretion onto black holes, among other similar mechanisms. He also works with large multi-wavelength surveys of galaxies to study the connection between galaxies and their central super-massive black holes.
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