Comet’s Approach To Earth On Dec. 21 Revives Debate Over Alien Technology

The object, known as 3I/ATLAS, will make its closest approach to Earth around Dec. 21, passing safely at a distance of roughly 170 million miles. It is only the third confirmed interstellar object ever observed entering the solar system, following ‘Oumuamua in 2017 and 2I/Borisov in 2019.

Because it originated around another star, 3I/ATLAS is, by definition, alien — but some observers have taken that idea further, speculating online and in fringe scientific discussions about whether the object could represent extraterrestrial technology.

Mainstream astronomers say there is no evidence to support that claim.

“There is currently no evidence whatsoever that this object is artificial,” a NASA planetary scientist said. “Everything we’re observing — its trajectory, its activity, its composition — is consistent with a natural interstellar comet.”

Why the Speculation Exists

Interstellar objects fascinate scientists because they are physical samples from other solar systems, formed under conditions different from those around the Sun. Their rarity means early observations are often incomplete, leaving room for uncertainty.

Some researchers note that past interstellar visitors have displayed unusual behavior, such as unexpected brightness changes or subtle accelerations, which initially lacked clear explanations.

That uncertainty has led a small group of scientists to argue that artificial origins should not be dismissed outright.

“Interstellar objects deserve serious scientific scrutiny,” said Avi Loeb, a Harvard astrophysicist who has publicly suggested that some past visitors could, in theory, be technological artifacts. “We should not assume that everything unfamiliar is automatically natural. Science advances by testing possibilities, not dismissing them.”

Loeb emphasizes that speculation does not equal proof.

“If an advanced civilization sent probes the size of asteroids, we would almost certainly mistake them for natural objects at first glance,” he said. “That doesn’t mean this comet is artificial — but it means the question is scientifically legitimate.”

The Scientific Pushback

Most astronomers strongly disagree that 3I/ATLAS shows any signs of being engineered.

The comet is exhibiting classic cometary activity, including a growing coma of gas and dust as solar heating vaporizes surface ice. Its motion follows a predictable gravitational path, with no signs of controlled propulsion or structured emissions.

“Interstellar does not mean intelligent,” said a senior astronomer at a major U.S. observatory. “It simply means the object formed around another star. Nature is extremely good at producing strange things without invoking technology.”

Scientists also point to lessons learned from earlier debates.

“We’ve seen this before with ‘Oumuamua,” the astronomer said. “Initial uncertainty led to speculation, but as data improved, natural explanations proved sufficient.”

No Signals, No Threat

Researchers affiliated with the Search for Extraterrestrial Intelligence (SETI) say the comet has produced no radio signals, no artificial light patterns, and no evidence of structure — the types of markers scientists would expect from technology.

“Extraordinary claims require extraordinary evidence,” a SETI researcher said. “So far, we see none — no signals, no propulsion, no structure — just a fast-moving comet doing comet things.”

NASA and international space agencies stress that 3I/ATLAS poses no risk to Earth and is being closely monitored for scientific purposes only.

A Rare Natural Visitor

As the comet slips past Earth during the darkest days of December, astronomers say its real value lies not in speculation, but in what it can teach scientists about how planetary systems form across the galaxy.

“People want cosmic mystery,” the SETI researcher said. “That’s understandable. But the real wonder here is that material from another star system is passing through our solar system at all.”

For now, scientists say, the evidence points firmly toward a natural interstellar comet, not alien technology — a reminder that the universe can be extraordinary even without intelligent design behind every anomaly.

“If alien technology ever passes near Earth, we hope to recognize it,” the NASA scientist said. “But science works best when we follow the data — not the excitement.”

What Would Alien Technology Actually Look Like?

Astronomers say that if an extraterrestrial probe or piece of alien technology ever passed near Earth, it would likely stand out — not by looking like a flying saucer, but by behaving in ways that defy natural physics.

Scientists point to several indicators that would raise serious red flags:

Non-gravitational maneuvering
An artificial object might change speed or direction in ways that cannot be explained by gravity, outgassing, or solar radiation pressure. Controlled course corrections would be especially suspicious.

Artificial signals
Radio transmissions, laser pulses, or repeating electromagnetic patterns — particularly narrow-band signals — would be strong evidence of technology. No such emissions have been detected from 3I/ATLAS.

Unnatural structure or symmetry
Highly regular shapes, flat surfaces, or repeating geometric patterns could suggest engineering. Natural objects tend to be irregular, fractured, and asymmetrical.

Extreme material properties
Materials that withstand intense heat without degrading, or that reflect light in unusual, highly efficient ways, could point to non-natural origins. Current observations show 3I/ATLAS behaving like an icy, dusty comet.

Energy generation or exhaust
Detectable heat signatures, exhaust plumes, or energy output inconsistent with sunlight absorption would draw immediate attention. None have been observed.

Why Scientists Are Confident This Isn’t It

Astronomers say 3I/ATLAS checks none of those boxes. Its motion follows gravity, its activity matches known comet physics, and it emits no detectable signals.

Interstellar objects may be rare, but researchers expect many more to be discovered as telescope surveys improve — and most, they say, will turn out to be natural.

Still, scientists agree on one thing: keeping an open — but disciplined — mind matters.

As one researcher put it, “The universe is vast. If technology is out there, we’ll find it by evidence — not by assuming it’s hiding inside every comet.

What ‘Oumuamua Taught Scientists About Alien Technology Claims

When the interstellar object ‘Oumuamua passed through the solar system in 2017, it became the first known visitor from another star — and a case study in how speculation can outpace evidence.

‘Oumuamua showed several unusual features. It had no visible comet tail, its brightness changed sharply, and it appeared to accelerate slightly as it left the solar system. Those observations led a small number of researchers to suggest it could be artificial.

Further study shifted the scientific consensus.

Later research indicated the acceleration could be explained by outgassing of hydrogen or nitrogen ice, a process that produces little visible dust. Scientists also concluded the object’s brightness changes were likely caused by an elongated, tumbling shape, not engineered structure.

Astronomers say those lessons apply to 3I/ATLAS, the interstellar comet now passing through the inner solar system.

Unlike ‘Oumuamua, 3I/ATLAS is showing typical comet activity, including a visible coma of gas and dust as it warms near the sun. Its motion follows gravity, with no unexplained acceleration or detectable signals.

Scientists say interstellar objects are expected to appear unusual at first, especially when observed for a limited time.

The consensus view remains that extraordinary claims require extraordinary evidence — and so far, none has been found.