Alien Probes May Have Already Visited Earth, Scientist Says

"Earth has had biosignatures for 3 billion years."

Breaking the Law

With official government inquiries into so-called "unidentified anomalous phenomena" (UAPs), the concept of extraterrestrial contact has never seemed closer — but alas, there are still major logistical hurdles for any aliens looking to swing by.

In interviews with Popular Mechanics about the nitty gritty of alien probes, space experts from schools in New York and California laid out a core tension in the search for intelligent life. On the one hand, life on Earth has been detectable from afar for a very long time. On the other, there are all kinds of pesky physics realities that would make it extraordinarily difficult to actually send a probe here.

"Earth has had biosignatures for 3 billion years," University of Rochester astrophysics professor Adam Frank told the outlet. "If there are [such things] as space-faring civilizations, it is not beyond possibility that somewhere in those 3 billion or 4 billion years that somebody came through, or somebody sent probes."

But, he warned, unless ETs discover improbable new laws of physics that help them travel faster than the speed of light, master the kind of "warp-drive" tech seen in sci-fi films, or have managed to access wormholes, the sheer distance would be an unbelievable obstacle.

"Anything going faster than light is science fiction right now because the laws of physics say that you can’t do that," Frank told the magazine. "Speed of light is as fast as you’re gonna go."

Diamond Rain

And Scott McCormack, an assistant professor of engineering and material science at the University of California, Davis said that even if alien civilizations did manage to figure out how to travel faster than light speed, they'd still have to deal with all that space junk that would pummel their crafts en route.

Per the reasoning of the UC Davis scientist, whose specialty is in materials that can withstand extreme conditions like those in space, ETs would need spaceships as hard as — or harder than — diamonds, and far more durable.

"To resist these impacts, you want to have a material that’s going to have both high hardness [to resist being deformed] and high fracture toughness," McCormack said. "What material could that be? I don’t think we have an answer yet."

But with all that time, like Frank said, you'd think that if anyone was out there, there's a decent chance they would have both spotted our lonely planet and sent something to go check it out. So, the consensus seems to be, it's worth it to keep looking.

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