NASA captures mysterious 'holes' in the sky

Have you ever looked up at the sky and thought something strange was going on?

That's exactly what happened to a group of fishermen in Florida, when they were out on the water and saw unusual, circle-shaped clouds.

American TikToker @blacktiph - who has 3.8 million followers - posted a video of the phenomenon with the caption: "Has anyone seen clouds like these before? We were fishing off Key West."

The video shows a light layer of clouds across the sky - which seems pretty uniform, until you spot a few circles that have been stamped out of the cloud cover.

The fishermen were obviously confused by this unique happening, and one voice can be heard saying: "Bro, look at these clouds, what is that? What is going on here with these clouds?

It's hard to see circles in the sky and not think of extraterrestrial activity, with one comment reading: "I've seen enough alien invasion movies to know exactly what those are."

But before you start making a tinfoil hat and practicing alien dialects, you should probably know that there's actually a logical explanation for this - and who better to break it down than NASA?

The space agency posted an aerial shot, which appears to show a similar cloud pattern seen in the TikTok video.

Apparently, these are Cavum clouds, also known as hole-punch clouds or fallstreak holes, and NASA says they're actually caused by airplanes.

"Cavum clouds form when planes fly through banks of altocumulus clouds, mid-level clouds that have supercooled (below the freezing point of water but still liquid) water droplets," NASA explains.

"As air moves around the plane, a process called adiabatic expansion can make the droplets freeze into ice crystals! The ice crystals eventually grow heavy and fall out of the sky, leaving a hole in the cloud layer."

NASA continues: "The falling ice crystals are visible in the center of the holes as wispy trails of precipitation that never reach the ground – features called virga."

NASA's satellite snap seems to confirm the TikToker's video, as it was taken over the Gulf of Mexico off of Florida’s west coast.

While a lot of people were blown away by the shot - with one person commenting: "Beautiful!" while another said: "We're pretty much obsessed with clouds at this point," others couldn't help but cracking jokes.

"No it’s just the astronaut breathing on the lens and drawing with finger," one Instagrammer joked, and another was a bit more skeptical, saying: "Aliens hiding..."