SETI Archives

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

June 5, 2021June 5, 2021 by Matthew Cimone

What Would It Take To See Artificial Lights at Proxima Centauri B?

Feature Image Description: Ecumenopolis Planet orbiting Proxima Centauri-like Red Dwarf Star - Graphics from the video game Stellaris, developed and published by Paradox Interactive. - used with permission

Is there an alien civilization next door? It’s…possible(ish). In late 2020, we discovered a signal from the direction of Proxima Centauri (not necessarily from Proxima Centauri), our closest neighbour star. Named BLC- 1 by project Break Through Listen, the signal is still being analyzed to ensure it isn’t simply an echo of our own civilization – typically what they turn out to be. But why not just directly look at planets in Proxima Centauri and see if a civilization is there?

From space, the most obvious sign somebody lives on Earth is the glow from the nightside of our planet. Our cities emit light that’s shed into the Cosmos. Problem is that our current generation of telescopes are not powerful enough to see lights on distant worlds. But several researchers are testing the capabilities of the next generation of telescopes already on the drawing board. The finding? Yes! if advanced enough…or glowy enough…we would be able to see if another civilization has the lights on at Proxima Centauri.

8k compilation of footage taken from the International Space Station orbiting above Earth’s City Lights

May 16, 2021May 17, 2021 by Matt Williams

60 Years Later, is it Time to Update the Drake Equation?

The Drake Equation, a mathematical formula for the probability of finding life or advanced civilizations in the universe. Credit: University of Rochester

On November 1^st, 1961, a number of prominent scientists converged on the National Radio Astronomy Observatory in Green Bank, West Virginia, for a three-day conference. A year earlier, this facility had been the site of the first modern SETI experiment (Project Ozma), where famed astronomers Frank Drake and Carl Sagan used the Green Bank telescope (aka. “Big Ear”) to monitor two nearby Sun-like stars – Epsilon Eridani and Tau Ceti.

While unsuccessful, Ozma became a focal point for scientists who were interested in this burgeoning field known as the Search for Extraterrestrial Intelligence (SETI). As a result, Drake and Sagan were motivated to hold the very first SETI conference, wherein the subject of looking for possible extraterrestrial radio signals would be discussed. In preparation for the meeting, Drake prepared the following heuristic equation:

N = R^ x f_p x n_e x f_l x f_i x f_c x L*

This would come to be known as the “Drake Equation,” which is considered by many to be one of the most renowned equations in the history of science. On the sixtieth anniversary of its creation, John Gertz – a film producer, amateur astronomer, board-member with BreakThrough Listen, and the three-term former chairman of the board for the SETI Institute – argues in a recent paper that a factor by factor reconsideration is in order.

May 7, 2021May 7, 2021 by Brian Koberlein

We Could Detect Extraterrestrial Satellite Megaconstellations Within a few Hundred Light-Years

A map of space debris orbiting Earth. Credit: European Space Agency

Starlink is one of the most ambitious space missions we’ve ever undertaken. The current plan is to put 12,000 communication satellites in low-Earth orbit, with the possibility of another 30,000 later. Just getting them into orbit is a huge engineering challenge, and with so many chunks of metal in orbit, some folks worry it could lead to a cascade of collisions that makes it impossible for satellites to survive. But suppose we solve these problems and Starlink is successful. What’s the next step? What if we take it further, creating a mega-constellation of satellites and space stations? What if an alien civilization has already created such a mega-constellation around their world? Could we see it from Earth?

May 2, 2021May 2, 2021 by Brian Koberlein

Breakthrough Listen Searched for Signals From Intelligent Civilizations Near the Center of the Milky Way

A view of the Green Bank Telescope. Credit: Jiuguang Wang/CC BY-SA 2.0

The Breakthrough Listen project has made several attempts to find evidence of alien civilizations through radio astronomy. Its latest effort focuses attention on the center of our galaxy.

April 28, 2021April 28, 2021 by Matt Williams

We Could Detect Alien Civilizations Through Their Interstellar Quantum Communication

The Parkes radio telescope at Parkes Observatory in New South Wales, Australia. Astronomers using the telescope detected what appeared to be a radio signal coming from the direction of Proxima Centauri in April and May 2019. Image via Daniel John Reardon/ Wikimedia Commons.

Since the mid-20th century, scientists have been looking for evidence of intelligent life beyond our Solar System. For much of that time, scientists who are engaged in the search for extraterrestrial intelligence (SETI) have relied on radio astronomy surveys to search for signs of technological activity (aka. “technosignatures“). With 4,375 exoplanets confirmed (and counting!) even greater efforts are expected to happen in the near future.

In anticipation of these efforts, researchers have been considering other possible technosignatures that we should be on the lookout for. According to Michael Hippke, a visiting scholar at the UC Berkeley SETI Research Center, the search should also be expanded to include quantum communication. In an age where quantum computing and related technologies are nearing fruition, it makes sense to look for signs of them elsewhere.

April 8, 2021April 8, 2021 by Andy Tomaswick

What are the Best Ways to Search for Technosignatures?

The search for extraterrestrial intelligence (SETI) has long roots in human history. With the advent of modern technologies, scientists were finally able to start scanning the skies for any sign of life. When the search first started back in the 1960s, it focused almost exclusively on trying to detect radio signals. Over the decades, no irrefutable evidence of any artificial radio signals was ever found. Financial support started to drift away from the discipline, and where the money goes so do many scientists.

But more recently, the spike in interest in exoplanet research has breathed new life into the search for intelligent life, now commonly referred to as the search for “technosignatures”. In 2018, NASA sponsored a conference where scientists who were involved with the field came to discuss its current state. That meeting was followed up by a meeting last year sponsored by the Blue Marble Institute, which NASA also helped to sponsor. Now a working paper has come out from the group of SETI scientists that attended the conference. Numerous potential mission ideas to find technosignatures are described in the paper. It’s clear the search for extraterrestrial intelligence isn’t limited just to radio astronomy anymore.

January 17, 2021January 17, 2021 by Matt Williams

According to the Math, it’s Highly Unlikely That an Intelligent Civilization is Located at Alpha Centauri

In December of 2020, the world got a bit of a pre-holiday surprise when it was announced that astronomers at the Parkes radio telescope in Australia had detected a “tantalizing” signal coming from Proxima Centauri (the red dwarf companion of the Alpha Centauri system). Afterward, researchers at Breakthrough Listen consulted the data on the signal – Breakthrough Listen Candidate 1 (BLC1) – and noted the same curious features.

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.

Aim for the Center

N = R* x fp x ne x fl x fi x fc x L

N = R^ x f_p x n_e x f_l x f_i x f_c x L*