One of many largest searches for alien intelligence in historical past is nearing completion, due to the assistance of greater than 2 million citizen scientists and the legendary Arecibo Observatory.
Launched in 1999, the SETI@Residence undertaking enlisted hundreds of thousands of volunteers world wide to assist determine uncommon radio indicators in information from the Arecibo Observatory — a large radio telescope in Puerto Rico that collapsed in 2020 as a consequence of a cable failure. Although the undertaking ended prematurely with the telescope’s demise, citizen scientists nonetheless recognized greater than 12 billion indicators of curiosity in 21 years of information.
Thus far, there isn’t a smoking-gun proof of alien transmissions from any of those radio sources. Nonetheless, the group is enthusiastic that their huge dataset will assist make future hunts for extraterrestrials much more efficient.
“If we do not discover ET, what we are able to say is that we established a brand new sensitivity stage. If there have been a sign above a sure energy, we might have discovered it,” laptop scientist and undertaking co-founder David Anderson mentioned in a assertion. “We’ve a protracted listing of issues that we might have completed otherwise and that future sky survey tasks ought to do otherwise.”
ET enters the group chat
The seek for extraterrestrial intelligence (SETI) is a department of science that goals to detect and talk with superior alien civilizations utilizing radio indicators — the thought being that, if people have made it this far technologically, hypothetical alien lifeforms may need too.
The Arecibo telescope was a star participant within the SETI area; in 1974, a group of scientists together with Carl Sagan and Frank Drake despatched a radio transmission from Arecibo to a close-by star cluster in hopes of reaching an intelligence viewers. The well-known “Arecibo Message,” transmitted in binary code, included a human stick determine, a double-helix DNA construction, a mannequin of a carbon atom and a diagram of a telescope. (Sadly, E.T. has but to telephone house about it.)
One massive problem for SETI is that area is overflowing with radio waves; all the things from chilly hydrogen molecules to exploding stars emits some type of radio vitality. Discovering a significant detection of radio indicators from clever aliens amongst all this cosmic noise borders on the inconceivable.
To assist slim the search, the co-founders of SETI@Residence turned to crowd sourcing. The group requested volunteers to obtain a free software program program to their house computer systems, borrowing every laptop’s processing energy to research Arecibo’s newest scans of the evening sky.
Beginning within the mid-Nineties, the group deliberate their undertaking with 50,000 volunteers in thoughts. However inside a 12 months of the undertaking beginning, greater than 2 million customers in 100 nations have been working SETI@Residence on their computer systems.
“It went approach, approach, approach past our preliminary expectations,” Anderson mentioned. “I want to let that group and the world know that we really did some science.”
Increasing the search
In two papers printed in 2025 in The Astronomical Journal, Anderson and his colleagues describe the huge dataset their contributors collected, and the way the group analyzed it for the highest candidate indicators.
The undertaking targeted on radio indicators coming from the Milky Means close to the radio wavelength of 21 centimeters, which is the wavelength used to map hydrogen fuel within the galaxy. Astronomers routinely observe the universe at this frequency; a hypothetical alien civilization would know that, and make use of that frequency to spice up their possibilities of being detected, the researchers defined.
Utilizing a supercomputer supplied by the Max Planck Institute for Gravitational Physics in Germany, the group eradicated billions of false indicators and Earth-based sources of radio interference, dropping the candidate pool right down to 1,000,000. The group then analyzed essentially the most promising 1,000 radio sources manually, whittling them right down to the highest 100 contenders.
Thus far, nothing uncommon has jumped out of the outcomes.
“We’re, no doubt, essentially the most delicate narrow-band search of enormous parts of the sky, so we had one of the best likelihood of discovering one thing,” astronomer and SETI@Residence undertaking director Eric Korpela mentioned within the assertion. “So yeah, there’s slightly disappointment that we did not see something.”
Nonetheless, what’s computationally doable at this time far outpaces what was doable in 1999, when the undertaking started, Korpela added. Comparable surveys are being carried out by FAST and different radio telescopes world wide; the hunt for alien intelligence will proceed, and the information evaluation will solely get quicker and extra dependable going ahead.
“There’s nonetheless the potential that ET is in that information and we missed it simply by a hair,” Korpela concluded.
