Sky Fallstreak Hole Cloud

It is believed that a disruption in the stability of the cloud layer, such as that caused by a passing jet, may induce the domino process of evaporation which creates the hole. Such clouds are not unique to any one geographic area and have been photographed from the United States to Russia.
Because of their rarity and unusual appearance, fallstreak holes are often mistaken for or attributed to unidentified flying objects.