Not a Flying Saucer

This Image of the Week shows hulking, smooth, white structures in the sky behind Gemini North, one half of Gemini Observatory, operated by NSF NOIRLab, which sits on Maunakea, Hawai‘i. If at first glance you thought the white shapes on the left looked like a flying saucer, then you are not alone. The white oval structures are in fact beautiful examples of lenticular clouds. These clouds most often form over large objects on Earth’s surface, such as the dormant volcano Maunakea, and at high altitudes. Combined with their smooth, saucer-like shape and defined “edge”, lenticular clouds are sometimes mistaken for UFOs.