The stunning Aurora borealis was visible with the naked eye last night, bonfire night, here on North Uist in the Outer Hebrides. The picture above was taken from the cottage garden with the green of the aurora reflected in the sea. It was a stunning evening, cold and still and I could see the green of the Aurora glowing in the sky all around me. The camera picked up even more colour than was visible to the naked eye.
After taking some pictures looking out north over the bay I turned to the south and saw what looked a strange pink coloured stripe. At first I thought it must be a cloud and I took the photo below.
We have never seen this before and this is probably the rare phenomenon of "Steve". This spectacular ray in the sky was there for about an hour and as I continued taking photos it dispersed up diagonally to the right. Being in a dark sky area countless stars were visible and glistening like diamonds. "Steve in the sky with diamonds" reminds me of that famous Beatles song.
What is "Steve"?
Steve is very rare and the aurora must also be present for it to appear. It is thought that Steve is made up of a fast moving stream of extremely hot particles called a subauroral ion drift (SAID). It appears as a ribbon or ray and lasts for between about 20 minutes to an hour. In 2019 the European Space Agency analysed photographs of Steve and estimated that the optical emissions of Steve range from 130 - 270 km in altitude. In comparison the Aurora borealis are caused by electrons colliding with the atmosphere at roughly 100km above the surface of the earth.
Why is it called "Steve"?
This natural light display got the name Steve in 2016 from a scene in an animated film "Over the Hedge" where animals gave the name Steve to a mysterious object they had never seen before. By giving this object a name it appeared less frightening to them. Scientists subsequently used the name for an acronym - Strong Thermal Emission Velocity Enhancement.
Later in the evening the aurora became more orange in colour, which you can see in the photo above.
Memories of this stunning natural light display and Steve lighting up the sky on bonfire night will stay with me forever. The cycle of solar activity is still increasing and hopefully we will all have more chances to watch the aurora dancing across the sky in the next few months.
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