The search for strange artifacts has come into focus

There’s no denying it The attraction of exotic antiques. Science fiction is steeped in the physical remains of extraterrestrial civilizations, appearing in everything from classic books by Arthur C. Clark and even gaming franchises like Mass effect and Outer wilds.

The discovery of the first interstellar objects in the solar system over the past decade has sparked speculation that they may be alien artifacts or spaceships, although the scientific consensus remains that these three visitors have natural explanations.

However, scientists have speculated about the possibility of encountering alien artifacts since the dawn of the Space Age.

“In the history of technological fingerprinting, the possibility of artifacts in the solar system has been around for a long time,” says Adam Frank, a professor of astrophysics at the University of Rochester.

“We’ve been thinking about this for decades. We’ve been waiting for this to happen,” he continues. “But being a responsible scientist means holding up to the highest standards of evidence and not crying too much.”

This raises some puzzling questions: What is the best way to search for alien artifacts? And what should we do if we have already identified one? Given that these technosignatures can run the gamut from tiny specks of alloy to huge spaceships — or perhaps some material beyond the imagination of Earthlings — it’s hard to know what to expect.

To address this challenge, researchers are currently working on a range of techniques to search for signs of alien remains throughout our solar system, including in orbit around Earth.

For example, Beatriz Villarroel, assistant professor of astronomy at the Nordic Institute for Theoretical Physics, has focused on a largely untapped observational resource: historical images of the sky taken before the human space age.

By studying archival photographic observations taken by telescopes before the launch of Sputnik in 1957, Villarroel produced an image of the sky before it was smeared by our satellites. As the leader of the Vanishing and Appearing in a Century of Observations (VASCO) project, she initially looked for any evidence that stars, or other natural objects, might disappear on these archival panels.

Instead, Villarroel found inexplicable “transients” that looked like satellites in Earth orbit, long before the Sputnik launch, which she and her colleagues reported in 2021.

“That’s when I realized that this is actually a wonderful archive, not to look for fading stars, but to look for artifacts,” she says.

Last year, Villarroel and her colleagues published three more studies on the search for near-Earth alien artifacts in publications of the Astronomical Society of the Pacific, Monthly Notices of the Royal Astronomical Society, and scientific reports that sparked spirited debate among scientists. Researchers have proposed a range of alternative explanations for these transient events, which could involve instrumental faults, meteorites, or debris from nuclear testing.

The mystery will likely be solved through a mission dedicated to searching for artifacts in geosynchronous orbit, an environment about 22,000 miles above Earth. However, Villarroel doubts that such a mission will get the green light by any federal space agency in the near term, due to the controversial nature of the topic.

She adds: “There are so many taboos that no one will take such findings seriously until such an investigation is dropped.”

Frank says he agrees that stigmatizing the search for otherworldly artifacts — and the search for alien life, more broadly — is counterproductive. But he believes that opposition to research into space artifacts is a healthy and natural part of scientific research.