SETI Archives

March 29, 2022March 29, 2022 by Matt Williams

Astronomers Come up With a New Message to let the Aliens Know we’re Here

The globally distributed dishes of the European VLBI Network are linked with each other and the 305-m William E. Gordon Telescope at the Arecibo Observatory in Puerto Rico. Credit: Danielle Futselaar.

On Nov. 16th, 1974, the most powerful signal ever beamed into space was broadcast from the Arecibo Radio Telescope in Peurto Rico. Designed by famed SETI researcher Frank Drake (creator of the Drake Equation) and famed science communicator Carl Sagan, the broadcast was intended to demonstrate humanity’s level of technological achievement. Forty-eight years later, the Arecibo Message remains the most well-known attempt to Message Extraterrestrial Intelligence (METI).

To mark the occasion, an international team made of researchers led by Jonathan H. Jiang of NASA’s Jet Propulsion Laboratory has come up with a new signal! Known as The Beacon in the Galaxy (BITG) message, this updated signal combines aspects of the original Arecibo Message with every METI attempt made to date – like the Pioneer Plaques, the Voyager Golden Records, and the Evpatoria Transmission Messages (ETMs).

March 20, 2022March 20, 2022 by Matt Williams

Why Would an Alien Civilization Send Out Von Neumann Probes? Lots of Reasons, says a new Study

Artist's concept of the New Horizons spacecraft encountering a Kuiper Belt object, part of an extended mission after the spacecraft’s July 2015 Pluto flyby. Credits: NASA/JHUAPL/SwRI

In 1948-49, mathematician, physicist, computer scientist, and engineer John von Neumann introduced the world to his idea of “Universal Assemblers,” a species of self-replicating robots. Von Neumann’s ideas and notes were later compiled in a book titled “Theory of self-reproducing automata,” published in 1966 (after his death). In time, this theory would have implications for the Search for Extraterrestrial Intelligence (SETI), with theorists stating that advanced intelligence must have deployed such probes already.

The reasons and technical challenges of taking the self-replicating probe route are explored in a recent paper by Gregory L. Matloff, an associate professor at the New York City College of Technology (NYCCT). In addition to exploring why an advanced species would opt to explore the galaxy using Von Neumann probes (which could include us someday), he explored possible methods for interstellar travel, strategies for exploration, and where these probes might be found.

February 14, 2022February 14, 2022 by Evan Gough

Astronomers Scan the Center of the Milky Way for Any Sign of Intelligent Civilizations. Nothing but Silence.

This is an image of the center of the Milky Way. The bright white area right of center is home of the supermassive black hole Sagittarius A star. Image Credit: By NASA/JPL-Caltech/ESA/CXC/STScI - http://photojournal.jpl.nasa.gov/catalog/PIA12348See also http://www.spacetelescope.org/images/opo0928a/ and http://hubblesite.org/newscenter/archive/releases/2009/28/image/a/, Public Domain, https://commons.wikimedia.org/w/index.php?curid=24958921

Are there civilizations somewhere else in the Universe? Somewhere else in the Milky Way? That’s one of our overarching questions, and an answer in the affirmative would be profound.

Humanity’s pursued the Search for Extraterrestrial Intelligence (SETI) in one form or another since shortly after the advent of radio waves in the early 20th century. Efforts have waxed and waned over the decades, but the search has never been completely abandoned.

The search detected transient hints in the form of unexplained radio waves in the past, but nothing that comprises reliable evidence. Now a new search for technosignatures in the Milky Way’s center has turned up nothing.

January 10, 2022January 10, 2022 by Matt Williams

What is the Arecibo Message?

A team of astronomers from UCLA searched for "technosignatures" in the Kepler field data. Credit and Copyright: Danielle Futselaar

On November 16th, 1974, a coded radio message was broadcast from the Arecibo Observatory in Puerto Rico. The message contained information on mathematics, humanity, the Solar System, DNA, and the Observatory itself. The destination for this message was Messier 13 (NGC 6205 or “The Great Hercules Cluster”), a globular star cluster located about 25,000 light-years from Earth in the constellation of Hercules.

This historic signal was the Arecibo Message, humanity’s first attempt at Messaging Extraterrestrial Intelligence (METI). Almost fifty years later, the Message remains a focal point in the Search for Extraterrestrial Intelligence (SETI), the ethics of messaging, and why we haven’t heard from any extraterrestrial civilization (the Fermi Paradox). What’s more, a growing movement today would like to see more METI efforts mounted in the future.

December 8, 2021December 8, 2021 by Matthew Cimone

A New Way to Detect Alien Megastructures

Dyson Sphere as Depicted in the videogame "Stellaris", developed and published by Paradox Interactive. Used with permission. Screenshot by author

How do you power a super advanced alien civilization? Soak up a star. We harness the power of the Sun using solar panels. What if you were to scale this idea to astronomical proportions? Surround an entire star with solar collecting structures or satellites to power your sprawling alien galactic empire. Such massive structures are known as a “megastructures” – in this case a “Dyson Sphere.” We are already trying to detect possible megastructures in space using the dimming of a star and the glow of megastructure components in infrared light. But recent research provides a new detection method – a Dyson Sphere may cause its host star to swell and cool.

October 27, 2021October 27, 2021 by Matthew Cimone

The Radio Signal From Proxima Centauri Came From Earth After All

The three telescopes at CSIRO’s Parkes Observatory. Credit: Red Empire Media/CSIRO.

Turns out we were hearing ourselves! Earth can be a noisy place when listening to stars.

Late last year, a story was leaked indicating that the Murriyang radio telescope in Australia had detected a “signal-of-interest”. Dubbed “blc1” (Breakthrough Listen Candidate 1), the signal appeared to originate from the direction of Proxima Centauri, the closest neighbouring star to the Sun. The signal had yet to be fully analyzed when the story was leaked. Now that the analysis is complete, research shows blc1 is in fact “RFI” – radio frequency interference – and not an interstellar signal.

But while it’s not aliens – or “Proxima Centaurians” as lead author on the signal analysis Dr. Sofia Sheikh whimsically refers to them – new methodologies for conducting radio-based SETI (Search for Extraterrestrial Intelligence) have been developed by analyzing blc1; further honing our ability to distinguish future potential ET signals from our own planet.

Simulation of Proxima Centauri b , Rocky World in the Proxima Centauri System – SpaceEngine by author

October 14, 2021October 14, 2021 by Matthew Cimone

Advanced Civilizations Could use Their Stars to Communicate (and as Telescopes)

A schematic of a on-axis stellar relay transmission system, opening angles, distances, and sizes not to scale. The initial unfocused transmission beam may even have an annular pattern to prevent flux from being lost to the disk of the Sun.A reversed arrangement can be used to receive signals from a distant star by focusing rays onto the spacecraft. c. Kerby and Wright 2021

A Long Distance Call

E.T. managed to call home with a Speak and Spell, buzzsaw blade, and an umbrella. The reality of interstellar communication is a bit more complicated. Space is really, really big. The power needed to transmit a signal across the void is huge. However, rather than using super high power transmitters, recent research by Stephen Kerby and Jason T. Wright shows that we could make use of a natural signal gain boost built into solar systems – the gravitational lensing of a solar system’s star. Networking a series of stars as nodes could get signals across vast tracts of the Milky Way. And we may be able to detect if our Sun is already part of an alien galactic communication network.

Distant Satellites at the far reaches of the solar system may use the natural focusing of light by the Sun to communicate across space – c. NASA

August 10, 2021August 11, 2021 by Matt Williams

We’ll Have to Wait About 3,000 Years for a Reply From Intelligent Civilizations

Artist’s impression of CSIRO’s Australian SKA Pathfinder (ASKAP) radio telescope finding a fast radio burst and determining its precise location. The KECK, VLT and Gemini South optical telescopes joined ASKAP with follow-up observations to image the host galaxy. Credit: CSIRO/Dr Andrew Howells

As a field, the Search for Extraterrestrial Intelligence suffers from some rather significant constraints. Aside from the uncertainty involved (e.g., is there life beyond Earth we can actually communicate with?), there are the limitations imposed by technology and the very nature of space and time. For instance, scientists are forced to contend with the possibility that by the time a message is received by an intelligent species, the civilization that sent it will be long dead.

Harvard astronomers Amir Siraj and Abraham Loeb tackle this very question in a new study that recently appeared online. Taking their cue from the Copernican Principle, which states that humanity and Earth are representative of the norm (and not an outlier), they calculated that if any transmissions from Earth were heard by an extraterrestrial technological civilization (ETC), it would take about 3000 years to get a reply.

July 28, 2021July 29, 2021 by Matt Williams

A New Plan to Search for Extraterrestrial Artifacts at Earth and Across the Solar System

Swarm of laser-sail spacecraft leaving the solar system. Credit: Adrian Mann

On October 19th, 2017, astronomers made the first-ever detection of an interstellar object (ISO) in our Solar System. This body, named 1I/2017 U1 (‘Oumuamua), was spotted shortly after it flew by Earth on its way to the outer Solar System. Years later, astronomers are still hypothesizing what this object could have been (an interstellar “dust bunny,” hydrogen iceberg, nitrogen icebergs), with Harvard Prof. Abraham Loeb going as far as to suggest that it might have been an extraterrestrial solar sail.

Roughly three years later, interest in extraterrestrial visitors has not subsided, in part because of the release of the Pentagon report on the existence of “Unidentified Aerial Phenomena.” This prompted Loeb and several of his fellow scientists to form the Galileo Project, a multi-national, multi-institutional research team dedicated to bringing the search for Extraterrestrial Technological Civilizations (ETC) into the mainstream.

July 3, 2021July 3, 2021 by Matthew Cimone

The Center of the Milky Way is the Most Likely Place to Find a Galactic Civilization

Composite image of the Milky Way's core created by Hubble, Spitzer, and Chandra telescopes. Credit X-ray: NASA/CXC/UMass/D. Wang et al.; Optical: NASA/ESA/STScI/D.Wang et al.; IR: NASA/JPL-Caltech/SSC/S.Stolovy

Aim for the Center

The Milky Way is 13 BILLION years old. Some of our Galaxy’s oldest stars were born near the beginning of the Universe itself. During all these eons of time, we know at least one technological civilization has been born – US!

But if the Galaxy is so ancient, and we know it can create life, why haven’t we heard from anybody else? If another civilization was just 0.1% of the Galaxy’s age older than we are, they would be millions of years further along than us and presumably more advanced. If we are already on the cusp of sending life to other worlds, shouldn’t the Milky Way be teeming with alien ships and colonies by now?

Maybe. But it’s also possible that we’ve been looking in the wrong place. Recent computer simulations by Jason T. Wright et al suggest that the best place to look for ancient space-faring civilizations might be the core of the Galaxy, a relatively unexplored target in the search for extra terrestrial intelligence.

Animation showing the settlement of the galaxy. White points are unsettled stars, magenta spheres are settled stars, and white cubes represent a settlement ship in transit. The spiral structure formed is due to galactic shear as the settlement wave expands. Once the Galaxy’s center is reached, the rate of colonization increases dramatically. Credit: Wright et al