Many residents of Victoria, Australia, as well as people around the world who saw the pictures were puzzled, scared, freaked out and occasionally impressed by the appearance of a giant hole in the sky. For a change, this one has a solid scientific explanation – and one possible cause that’s worth investigating.
The admittedly scary-looking multicolored hole in the clouds appeared over Wonthaggi in the Gippsland area of Victoria on November 3. Photographs, videos and panicked messages hit the Internet almost immediately. It was described as everything from a UFO to a mothership to something from the movie “Independence Day” to a harbinger of the end of the world, or at least the Rapture. So what was it?
Weather.com meteorologist Linda Lam says it was a fallstreak hole. A what?
A fallstreak hole is a circular or elliptical gap that can appear in high- to mid-level clouds. There are water droplets in the cloud that have yet to freeze, and once they do (when ice crystals are introduced), the water droplet freezes and grows. As it grows, it begins to fall and a hole is left behind.
I’m not sure I would use the words “left behind” around people who think it’s the Rapture. Michael Efron, a forecaster for the Bureau of Meteorology, says it’s also known as a punch hole cloud and explains the unusual colors and contrasts.
This type of [cloud] iridescence occurs with high level cloud and with diffraction, [meaning] that water droplets are gathering light.
Whatever you call them – some people also call them crop circles in the sky – these cloud formations are usually rare but have been seen with increasing frequency this year. One was spotted in Perth in October and another in Northern California in May.
Why are they forming more frequently? It could be because many of them are man-made. That’s right, contrail watchers. Fallstreak holes can be created when aircraft propellers and wings pass through clouds and form the ice crystals that fall and create a hole.
Aircraft creating things that eventually fall to earth? Why would they be doing that?