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."
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