If you believe in UFOs, you're not alone. These 8 celebs all swear they've seen some extra-terrestrial stuff flying around up there. But if you're more of a skeptic, NASA employee James Oberg has some explanations behind some of the most common "UFO" sightings.
It all boils down to the human sensory system, which is sorely underprepared to absorb the kind of stuff that happens in outer space. Oberg told Atlas Obscura:
"Our sensory system is functioning absolutely perfectly for Earth conditions. But we're still a local civilization. Moving beyond our neighborhood has been visually confusing."
He explained three major space phenomena that commonly get misconstrued as alien activity, but are really completely logical occurrences... or are they?
1. Super-High Plumes
Remember when most of California — including the Kardashians — flipped their lid over a blue UFO in November 2015? The US Navy was quick to jump in and say it was just a test missile, but many believers were unconvinced. We see plumes behind planes all the time; they look like long skinny trails of smoke or something. But this plume was BIG.
Watch it again in this clip:
According to Oberg, rocket plumes spread out into much wider cones because they don't have the added pressure of air. Some of the particles even hit the rocket and wind up in front of it or next to it, and the plume can grow bigger and bigger. Oberg says this about the reactions most people experienced:
"There were thousands of people who were absolutely processing their visual stimuli correctly if [the plume] was a mile away or ten miles away. But it was 300 miles away, up in space and sunlit, which never occurred to them, because this is not something within the normal range of human experience."
2. Space Dandruff
Some of the videos that seemed the most legit are those that came from NASA and other space camps themselves. Mysterious, floating objects drifted in front of the camera. What is that stuff???
The answer is kind of anticlimactic: It's what Oberg calls "space dandruff." Because the spots are able to stay in view of the camera for several seconds, they are almost (almost!) certainly close to the shuttle, rather than far away. Probably just flakes of ice or bits of crap from the shuttle itself that have fallen off and are still floating around out there.
But Oberg does admit that they're mesmerizing. He and his colleagues at NASA used to watch the videos of space dandruff for fun. He waxed nostalgic to Atlas Obscura:
"The earth's still dark, the sky is full of stars, and these little snowflakes are playing out there, tumbling."
3. Twilight Shadowing
So you know how when the sun hits something, that something creates a shadow? Well the same thing happens in space with space shuttles, only there's usually nothing for the shadow to show up on. But sometimes, particles of space dandruff or whatnot float in and out of where the shadow would be, and you get what's known as "twilight shadowing." Oberg describes it like this:
"They tend to occur at a very special time every orbit, when the shuttle has just come up out of the Earth's shadow and is now bathed in sunlight. The camera is pointed back toward the receding horizon, and stuff suddenly appears, like it's coming up from behind the horizon, or behind a cloud."
You can see it in action in this video:
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Source: Atlas Obscura