September 20 2014 Latest news:
Saturday, March 1, 2014
The celestial show which set the social media sphere ablaze with stunning photographs was the most spectacular appearance of the aurora borealis in 20 years, according to astronomers.
North Norfolk’s sky became a palette of dancing red and green lights on Thursday evening after a large explosion on the sun’s surface earlier in the week.
Mark Thompson, president of the Norwich Astronomical Society, said it was the combination of the size of the solar flare, the speed of the particles sent out into the solar system and the orientation of the earth which caused the display to be as visible as what it was.
He said although there have been displays seen over Norfolk in recent years, including in early 2006, this week’s was the most impressive in two decades.
Mr Thompson said: “The last time we saw anything as spectacular was 20 years ago, there hasn’t been anything as bright as what we saw on Thursday night since then. There are a number of factors which determine how spectacular or how impressive the display is: how much stuff is sent out, the size of the flare, the speed of the particles - and this was a particular fast bunch - and the orientation of the earth when it strikes us. There are a number of variables which determine how good it is.
“We were lucky that everything came together to give us a nice display and it was a nice, clear night as well.”
The Northern Lights are caused by a large explosion on the surface of the sun, called a coronal mass ejection, that sends a flare of particles out into the solar system. If the earth happens to be in the way, those charged particles interact with the earth’s magnetic field which will then funnel that energy to the poles.
“The gases in the earth’s atmosphere, nitrogen and oxygen, light up in the same way you see a flourescent tube light up, they are the green and reds that we see,” said NAS secretary Dave Cook.
“We don’t see them this far south often because in order to push the lights that far south, you need a huge amount of energy and that means the solar flare has to be very large. The solar flare on Tuesday was massive.”