The AI-Powered Hunt for E.T.

Alien Intelligence: How A.I. is Turbocharging the Search for E.T.

Imagine a distant world orbiting a faraway star. On its surface, an alien civilization broadcasts radio and TV signals out into space, unaware that over dozens of lightyears away, a radio telescope on Earth has detected their presence. This long-imagined moment of first contact has eluded us so far, but an unlikely ally may bring us closer: artificial intelligence.

The search for extraterrestrial intelligence (SETI) has traditionally relied on human eyes and ears sorting through radio telescope data. But machine learning algorithms can now analyze signals millions of times faster, uncovering patterns we easily miss. AI is turbocharging SETI with capabilities beyond our biological limits.

At UC Berkeley, the Breakthrough Listen project has amassed petabytes of data in the hunt for ET. "We realized several years ago that the volumes we're generating are beyond human scale," says Andrew Siemion, the initiative's lead. "Machine learning became critical for us."

In 2019, an undergraduate named Peter Ma developed an algorithm to vet SETI candidates from these massive datasets. By training on millions of samples, it learned to automatically flag anomalies worthy of followup. When let loose on telescope data already inspected by humans, it surfaced eight new signals missed before.

"The improvements are really staggering," says astronomer Steve Croft. "AI can be an invaluable partner in the search."

Meanwhile at Penn State, Jason Wright is training computers to recognize chemical signatures of life in exoplanet atmospheres. Kepler and other telescopes have found thousands of worlds orbiting distant stars. Now the race is on to scan their atmospheres for traces of biology.

"Finding life ultimately will come down to recognizing patterns in data," explains Wright. "That's a perfect machine learning problem." Neural networks can be primed to identify exoplanets likely harboring alien biospheres.

Rather than teaching the computer what to look for, UC Santa Cruz’s Eric Korpela takes an open-ended approach. His algorithms ingest raw telescope data and find whatever seems unusual, with no human guidance. This avoids inherent biases that could cause supervised algorithms to overlook unexpected signals.

"Letting the machine learn without guidance leads to the most flexible, sensitive system," says Korpela. Alien messages could resemble nothing we anticipate.

Of course, today's AI has limitations. "We have to be careful that enthusiasm for AI doesn't lead to misplaced expectations," cautions Andrew Siemion. "These technologies are very powerful but also fundamentally unintelligent."

Nonetheless, computers' speed and rigor already complement human creativity and intuition. Scientists see many other applications for AI in the cosmic search for life.

Onboard Spaceships

Future probes bound for Europa or Enceladus could be equipped with autonomous AI to explore in real time. If the spacecraft detected plumes erupting from an icy moon, algorithms could instantly analyze the material for signs of biology, plot a course toward the source, and determine where to point instruments next - no wait for instructions from Earth.

"An AI explorer could rapidly follow up on discoveries we'd otherwise miss," says exoplanet scientist Jessie Christiansen of Caltech. Onboard automation will let our emissaries probe alien worlds faster and smarter.

Exoplanet Modeling

Christiansen's colleagues at the Virtual Planetary Laboratory model hypothetical exoplanet environments to study conditions for life. But running all the permutations involves heavy computation. AI could take over these climate simulations to free up human time and run more variations.

"An AI might try novel combos of atmosphere, star type and planet rotation we didn't think to try but are compelling," says Christiansen. Algorithms could reveal inhabited worlds we overlooked.

Autonomous Telescopes

Rather than just crunching data, why not let AI take control of the telescopes? Jason Wright and colleagues are developing robotic systems that can independently scan skies, choose targets, acquire data and test hypotheses.

"I could see autonomous telescopes not just using machine learning to extract info from data, but actively choosing what data to go after," he says.

Handing telescopes over to artificial scientists could enable perspectives and experiments no human would think to try. The unexpected insights AI discovers could unveil our silent cosmic company.

Of course, keeping autonomous systems aligned with human values as AI capabilities grow remains an open challenge. Scientists emphasize transparency and maintaining human oversight of alien-hunting algorithms.

"We have to be thoughtful about how we train and apply these algorithms to avoid reinforcing our own biases," says Steve Croft. But used responsibly, AI can transcend the limits of human cognition.

Smarter Tools, Smarter Searches

From hunting laser beacons around distant exoplanets to extracting hidden patterns buried in static from radio telescopes, artificial intelligence is transforming how we search.

"AI allows us to greatly expand our intellectual capacity to look for life," says Andrew Siemion.

Algorithms unrelentingly comb through petabytes of data from SETI surveys, flag promising signals for followup, and even suggest new places to look. Automated systems guide future technologies to maximize our chance of success.

One day, through the technological augmentations of our mechanical assistants, that long-awaited discovery awaits - the first faint murmur of a greeting from beyond our world.

"AI is absolutely crucial for identifying ETI candidate signals amidst the noise," says Jason Wright. "This is a transformation in the whole field of SETI."

Sixty years ago, only human minds scoured the skies for alien messages. Today, artificial intelligences amplify our efforts. Silicon complements carbon. Machine learning provides clues human researchers overlook.

We have yet to meet our galactic neighbors, but advanced algorithms enhance the search. Our artificial collaborators awaken new possibilities. With their aid, perhaps the cosmic conversation awaits. We need only listen.