In less than a second, astronomers photographed a rare "elf lightning".

CTOnews.com, Sept. 7 (Xinhua)-- astronomer Stanislav Kaniansky captured a rare "elf lightning" phenomenon in Slovakia on August 12. The whole red lightning is more than 50 kilometers (31 miles) in diameter and lasts only a fraction of a second.

Elf lightning is difficult to capture because it is fleeting and is often obscured by thick clouds. Kaniansky said the shooting was about 320km (200miles) from the thunderstorm and had a good view above the clouds.

Spaceweather.com said the photo was "one of the most detailed images of elf lightning in history".

CTOnews.com inquires the relevant information, and here is the introduction of Elf Lightning as follows:

Elf lightning is an upward jet in the atmosphere 30 to 80 kilometers above the ground. It appears in the air for less than 1/30 seconds and is as elusive as a ghost. Lightning in the upper atmosphere is different from white lightning in the troposphere. The former appears from above the clouds and extends to outer space. It usually lasts less than a second and has a variety of colors, so it is also called transient luminous event (Transient Luminous Events,TLEs).