At first glance at this image, you’d be forgiven for mistaking it as a scene from a science-fiction blockbuster.
But the eerie image of bubble-like clouds is very much real, and was snapped over Hastings, Nebraska back in 2004.
NASA has now featured the image, which was taken by photographer Jorn Olsen, as its Astronomy Picture of the Day.
While clouds usually have a flat bottom, the clouds in this image are round.
NASA explained: “Normally, cloud bottoms are flat. This is because moist warm air that rises and cools will condense into water droplets at a specific temperature, which usually corresponds to a very specific height. As water droplets grow, an opaque cloud forms.
“Under some conditions, however, cloud pockets can develop that contain large droplets of water or ice that fall into clear air as they evaporate.”
These types of clouds are called mammatus clouds, and often form in turbulent air near thunderstorms.
According to the Met Office , they’re some of the most unusual forms of cloud.
It explained: “Mammatus clouds are some of the most unusual and distinctive clouds formations with a series of bulges or pouches emerging from the base of a cloud.
“The shape of mammatus formations can vary widely; from the classic protruding shape, to a more elongated tube hanging from the cloud above.”
