It's not an unknown occurrence that when strange things appear in the sky, onlookers take notice. But this time, the conditions may just be a bit stranger than usual.

Earlier this week Australians caught a glimpse of a bizarre sight in their morning sky, something that's not only rare, but also quite strange to see. Looking like a vortex for clouds, with a looming rainbow trapped in the center, Australians across the continent snapped shots of what they thought was an alien spacecraft, or rather a hole in the atmosphere. Taking to social media, the strange images garnered much attention, but as soon as the mystery was up, the strange solution was found.

Known as a "Fallstreak Hole", the phenomenon occurs when droplets in a cloud supercool below freezing, but without turning to ice-causing a strange structure and uniformity within the water molecules. Much more like a crystal, the cloud is able to create a rainbow that lingers in the sky.

"These 'supercooled' water droplets need a 'reason' to freeze, which usually comes in the form of ice crystals" researchers from the National Oceanic and Atmospheric Administration say. "Planes passing through the cloud layer can bring these ice crystals [to initiate the process]."

"Once the ice crystals are introduced, the water droplets quickly freeze, grow and start to fall. A hole is left behind, which will start to expand outward as neighboring droplets start to freeze."