It looks a lot like a UFO … but it’s what’s called a lenticular cloud. These lens-shaped clouds typically form where stable, moist air flows over a mountain, and they can appear and disappear quickly. Karen Racette captured this one floating over Butte, Montana, on October 7, 2019.
Eleanor Imster has helped write and edit EarthSky since 1995. She was an integral part of the award-winning EarthSky radio series almost since it began until it ended in 2013. Today, as Lead Editor at EarthSky.org, she helps present the science and nature stories and photos you enjoy. She also serves as one of the voices of EarthSky on social media platforms including Facebook, Twitter and G+. She and her husband live in Tennessee and have two grown sons.