Strange bubble cloud in the English sky

Dark night, crowded together like giant oil droplets and full of intimidation, the cloud in the sky of Hertfordshire last week looked like a special effect in horror movies.

But it is a perfect product of nature, and is also completely harmless, a meteorological phenomenon called mammatus cloud.

The photo taken by Ian Pattison outside his home in St Albans, Hertfordshire, England last week.Photo: Dailymail.

Named after Latin, meaning breasts, mammatus clouds are always accompanied by strong thunderstorms that can occur in the summer, and are a sign of a large amount of water vapor kept in the air.

Normal clouds consist of water droplets, ice crystals or mixes of both, and different cloud shapes are created by a number of factors such as temperature, water and ice ratio, cloud height and speed. wind in it.

But while most clouds have thin edges that are unclear, mammatus clouds (usually stable in minutes) have exceptionally clear and sharp boundaries. Each of its "drops" can have a diameter of up to 1 mile. They are also almost opaque, making the cloud look like it can be touched.