At www.spaceweather.com April 7th and 8th 2016 … we have news of a geomagnetic storm on April 7th – but with a difference. Although a giant sun spot is brewing on the face of the Sun this geomagnetic storm was caused by the Earth crossing a 'fold in the heliospheric current sheet' – plunging our planet into a region of space with 'negative polarity' magnetic fields. This sparked the colourful light show in the polar skies. Bright aurora appeared around the Arctic Circle. The image below was taken in Norway
and the second one in Scotland (and includes a meteor crossing the sky).
Many people have never heard of the heliospheric current sheet, Space Weather adds, but it is one of the biggest things in our solar system – a vast undulating system of electrical currents shaped like the skirt of a ballerina. 
The image was published in the journal Science in 1980 – see http://wso.stanford.edu/gifs/HCS.html
Meanwhile, the green comet, visible for weeks in the southern hemisphere, has now crossed the celestial equator and the view below was taken in New Mexico. It is the blown up atmosphere, or coma of the comet, that you can see. The nucleus is quite small. The atmosphere is around 90,000 km in diameter. It is barely visible by eyeball and a small telescope is advised in order to see the fuzz ball clearly. It will rise higher in the northern sky over the next few weeks. Tips on observation are available in 'Sky and Telescope' which is available at all good newsagents such as WH Smith. Tips are likely to be in other astronomy magazines also so don't restrict yourself to the recommended one if you don't like the cover story.
