In this photo taken on a smartphone camera by Leesa Willmott, a fallstreak hole forms in the sky over Wonthaggi, Australia. The bizarre sight seen Monday in the town near Melbourne looked like a hole in the sky, or perhaps an alien spacecraft. Bureau of Meteorology forecaster Adam Conroy said fallstreak holes are circular gaps that appear in high clouds when a section of the cloud freezes.
The ice crystals are heavy, so they fall out of the cloud, leaving a hole. It is a relatively rare phenomenon.