The U.S. government has shot down multiple unidentified flying objects out of North American airspace in recent days. This is not a drill.
The things downed over Alaska, Michigan and Canada's Yukon Territory are textbook UFOs. They're objects, they're flying and they're most definitely unidentified — so far, no one has been able to conclusively discern what they are or rule out any explanation for their presence.
That includes the possibility that they're not from this world.
"I haven't ruled out anything," Gen. Glen VanHerck, the head of NORAD and U.S. Northern Command, said when asked specifically about the possibility that the objects are extraterrestrial in origin. "At this point we continue to assess every threat or potential threat, unknown, that approaches North America with an attempt to identify it."
VanHerck may be keeping an open mind, but those most familiar with the reaches of outer space are more certain that these objects did not come from there.
Yes, the universe is a rich tapestry of mysteries. But it also abides by some fundamental laws of physics that make it extremely difficult for any object to travel across interstellar space and into our lower atmosphere undetected.
"Unidentified" doesn't mean "it's aliens" — it simply means that no one yet knows what it is. The number of unusual sightings that fit this criteria has increased in recent years, to the point where both the U.S. Department of Defense and NASA have embraced and legitimized the study of UFOs. They even gave the objects a new, more scientific-sounding name: unidentified anomalous phenomena, or UAPs.
U.S. military personnel have reported dozens of sightings of aerial objects that defy explanation, according to a report made public in 2021. Last year, NASA launched a study to determine which of its vast resources should be deployed toward further exploration of UAPs.
The goal is to remove the stigma of reporting a UAP sighting so that legitimate threats can be investigated. The Pentagon is at least as worried about the possibility of a new aerial weapon deployed by a foreign adversary as it is about aliens.
As for scientists, even those who accept the possibility that life may exist elsewhere in the universe are highly skeptical that the enigmatic objects are extraterrestrial. The bar for proving alien life is high, and these flying things — whatever they are — don't clear it.
"If you're claiming aliens came, that's kind of a big ol' hairy deal. We've never seen anything like that. That should never be the first place your brain goes," said Bruce Betts, chief scientist for the Planetary Society. "Odds are that's not the answer."
Here are a few of the reasons why aliens aren't likely to be the source of these unidentified objects.
Distance
Even astronomers who specialize in the search for extraterrestrial intelligence dismissed the possibility that these UAPs were sent by aliens.
"The impracticalities of interstellar travel are substantial," said Jean-Luc Margot, a planetary astronomer who leads UCLA's SETI (Search for Extraterrestrial Intelligence) Group.
Despite extensive efforts, the only life scientists have been able to identify in this solar system is right here on our planet. After our sun, the next closest star is Proxima Centauri, which is 4.3 light-years — 25.3 trillion miles — away.
Let's use Proxima Centauri as an example. Any object dispatched from its surrounding exoplanets would have to cross that staggering distance to get to us.
An object traveling 365,000 mph — just under the top speed of NASA's Parker Solar Probe, currently the fastest human-made object in the universe — would take 7,912 years to get from Proxima Centauri to us. If it could somehow travel at the speed of light — which would require so much energy that the slightest ding from an errant space rock would cause the craft to explode — it would still take more than four years to get here.
More significantly, any signals sent between the spacecraft and a base on its home planet would take those four-plus years to travel. That communication delay would complicate a mission involving an unmanned — unaliened? — robotic craft, Betts said.
A crewed mission would be even tougher.
"When you have size and mass and life support, spacecraft get big in a real hurry. That makes it even harder to make them go fast," Betts said.
This is just our closest star. There are 100 billion stars in our galaxy alone. The rest are even farther away.
Observation
Let's say our hypothetical alien spacecraft somehow manages to cross some significant part of the Milky Way and make it to our solar system. The closer the craft gets to Earth, the harder it will be for it to evade detection by the multitude of tools observing the cosmos around us.
The Solar Systems Dynamics Group at NASA's Jet Propulsion Laboratory alone is currently tracking the orbits of some 1.2 million small objects in Earth's immediate vicinity. Telescopes on the ground can spot objects the size of a duffel bag from tens of thousands of miles away, often years in advance of any approach to Earth.
When one of the smaller of these objects crashed through Earth's atmosphere on Monday — a 1-meter-wide asteroid named Sar2667 — the European Space Agency and NASA's Center for Near-Earth Object Studies knew well in advance how big it was, where it would enter the atmosphere (over northern France) and what time it would get there (around 4 a.m. Central European Time).
If these downed objects came from space, how did they manage to slip past all observation systems?
Besides, there's a more plausible explanation for the sudden increase in UAP detection. After the discovery of a Chinese surveillance balloon in U.S. airspace last week, the Pentagon has stepped up its scrutiny of objects in the sky. Things that would have been ignored in the past are now getting a closer look. That includes slower-moving objects that were detected after the U.S. adjusted its radar systems.
"We've been able to get a better categorization of radar tracks now," VanHerck said. "That's why I think you're seeing these, plus there's a heightened alert to look for this information."
Practical problems
Then there are a whole host of other questions.
Sar2667 had been speeding through the vacuum of space when it encountered the atmosphere, and the resulting friction caused it to burn up over the English Channel. If these UAPs came from outer space, how would they have survived the fiery entry into our atmosphere without similar destruction?
What kind of alien technology could survive a trip across space and safely enter the atmosphere, only to get downed by a missile above Lake Huron or Deadhorse, Alaska?
If there is an intelligent civilization out there, why would these easily destructible things be the way they signal their presence?
Medical students are told to picture horses and not zebras when they hear the sound of hoofbeats — a metaphor that cautions aspiring doctors not to be so distracted by the prospect of an exotic diagnosis that they overlook common explanations for a patient's symptoms.
The study of UAPs follows similar principles.
Betts invoked the phrase Carl Sagan popularized in regard to the search for extraterrestrial life: Extraordinary claims require extraordinary evidence. What we've seen so far from the UAPs above North America doesn't come close, he said.
"There's no reason to believe that it is from somewhere else. There are a range of explanations that are much easier to stomach," he said. "We have no solid evidence of aliens ever coming to our planet."
