Rare 'Steve' phenomenon spotted over Shetland

3rd March 2021 Last updated at 11:18

The aurora borealis can make a regular appearance over northern Scotland but on Tuesday night another phenomena was spotted in the Shetland Islands alongside it, as captured here by BBC Weather Watcher KevB.

Pale purple ribbon of light in night sky above a house
BBC Weather Watchers / KevB

The thin purple ribbon glowing in the sky is a relatively new scientific discovery often associated with the aurora.

While it has been photographed for decades, little was known about the phenomenon.

After a US citizen science project funded by NASA and the National Science Foundation from 2015 to 2016, the glow was named "Steve" by the aurora watchers, reportedly after a scene in the animated movie Over the Hedge where the characters use the name to refer to something they don't know about.

Scientists adapted the name to "Strong Thermal Emission Velocity Enhancement".

Little was known about its formation and why it can sometimes appear during an aurora display.

NASA's Goddard Space Flight Center has been studying Steve using pictures from the ground along with satellites.

While Steve is only spotted in the presence of an aurora, it is not a normal aurora.

While auroras happen globally in an oval shape, Steve appears as a ribbon and lasts for 20 minutes to an hour before it disappears.

In a study published in Science Advances the author Dr Liz McDonald suggests that Steve comprises of a fast moving stream of extremely hot particles called a subauroral ion drift, or SAID.

While SAIDs had been studied since the 1970s, scientists didn't know it had a visible light.

As Steve is unpredictable and only lasts for a short time, recording occurrences from the ground is rare, so KevB had a real treat.