Waiting for the Aurora

We are waiting for possibly good Aurora tonight in Finland. The sun has a very large sunspot on it  (it has a number AR1944).

Sunspot AR1944 which is big enough to fit 3 earths in it
Sunspot AR1944 which is big enough to fit 3 earths in it

Two days ago this very large sunspot emitted a solar flare and a Coronal Mass Ejection (CME) which has been heading towards the earth at 2000km per second. The sun was not facing the earth directly at the time of the CME, but it is expected to give the earth a glancing blow. This CME is big enough that NASA scrubbed the Cygnus resupply launch to the International Space Station.This CME is expected to distort  the earth’s geomagnetic field which is called a geomagnetic storm. The benefit of a geomagnetic storm is that it ….. creates Auroras!

However we need more things going our way, Firstly the CME is expected to hit in the middle of the day out time, and its not dark then (sunrise here is 11:30am sunset 1:30pm). However no one is quite sure when the CME will hit  and it could be some hours later. Secondly we need good weather. It has been snowing here in Särkijärven, Finland for the past 3 days and it does not make good Aurora viewing. However tonight it is meant to clearing,  with a crisp clear night of -20C.  At the moment it is still snowing so we can only cross our fingers and keep watching the Kiruna Magnetogram which indicates the affect of the CME on the earths magnetic field. Kiruna ia a couple of hundred kilometres west of here so it should give us a good warning.

kiruna-magnetogram

 

UPDATE: It is nearly 1am and no sign of Aurora. The CME has arrived but not as strong as predicted, so it looks like no geomagnetic storms. The weather is excellent for viewing with clear skys and -17C:

Minus 17C
Minus 17C