Rare red lightning photographed from space

Courtesy: NASA/JSC

Wednesday, August 26, 2015, 4:25 PM - Earlier this month, scientists aboard the International Space Station (ISS) snapped two photos elusive sprites -- 'red lightning' that only lasts for a few milliseconds, high up in the atmosphere.

There's still a lot of mystery surrounding sprites, which were discovered in 1989.

Scientists have managed to grab a handful of photos but their brief existence makes it difficult to gather data.

Sprites occur in conjunction with the lightning strikes we see on Earth but they don't happen every time. They're dimmer than traditional lightning and, because they're so high up, difficult to see with the naked eye.

Astronauts captured the sprite images on August 10 but they weren't released by NASA until August 24.

The photo above was captured over the U.S. Midwest.

Nearly three minutes later another sprite was photographed over Acapulco, Mexico.

Courtesy: NASA/JSC

Both sprites extended at least 100 kilometres above the Earth's surface.

One of the working theories is that sprites are caused by 'positive lightning' -- a rare for of lightning that has a positive charge and is ten times stronger than 'negative' lightning. Ninety-five percent of all lightning has a negative charge.

Positive lightning creates an intense flash, and that may be strong enough to break apart molecules in the atmosphere into ions, creating a cold plasma cloud.

It's believed the sprites are red due to the ions smashing into molecules.

Scientists hope further study will shed some light on the nature of sprites and whether the phenomenon impacts storms on Earth.