The radiant reds and gleaming greens that have decorated South Canterbury skies this year are set to stick around a little longer.
The Aurora Australis has captured the imagination of the region with many people flocking outdoors to capture their own photographs of the solar phenomenon.
Tūhura Otago Museum director and aurora enthusiast Dr Ian Griffin said auroras come around in a cycle of 11 years.
‘‘That cycle is tied to the sun because the sun has its own cycle of activity.
‘‘The number of auroras are related to the number of sunspots on the sun.
‘‘Basically, every 11 years the sun goes through this cycle of activity and when it comes close to maximum there are lots and lots of sunspots on the sun.’’
He said there had been lots of material from the sun fired towards the earth causing the aurora.
‘‘The fact we are seeing this many is because we’re coming close to the maximum phase of solar activity.’’
He said there were two main reasons why people had begun to take more notice of the aurora.
‘‘Firstly, I think the plethora of modern cameras we now have are much better at seeing auroras than the human eye,’’ Dr Griffin said.
‘‘This means if you go out with just a mobile phone you may very well see one, because your mobile phone is very, very sensitive. Every solar cycle was different, but the past couple had not been as good, he said.
‘‘This cycle is coming in much stronger than expected. We’ve got the combination of it peaking but also the cycle being particularly active, meaning we are getting a lot more auroras.’’
He said that since we were only reaching the peak of cycle, auroras could still be expected.
‘‘Scientists say we could expect to see them for probably another month, if not another year or so.
‘‘It’s quite a good time to be out there looking.
‘‘It’s a really interesting time, it’s a really exciting active cycle and I’d encourage people to get out and have a look because they are just beautiful things to look at.’’
It was also amazing to have had so many ‘‘STEVE’’ (strong thermal emission velocity enhancement) sightings, he said.
‘‘It’s actually not an aurora, it’s a plasma seen to the north of auroras.
‘‘No-one knows what causes it. It’s one of the great mysteries.
‘‘They are quite rare but oddly in the last six months, I think I’ve seen four or five of them.
‘‘The two, last Friday and the Tuesday before both had STEVEs and both had this great auroral arc.
‘‘I think because this has been a very active zone cycle we have been able to see the Steves and the picket fences, which are these lovely green things visible in the sky.’’
It was great to see so many people taking an interest.
‘‘There is a really good community and Timaru has some really experienced folks taking some pretty pictures.
‘‘The lovely thing is, though, you don’t actually have to be a super brainiac astronomy-type person. You can go out and just take pictures with your camera and see some really interesting things.
‘‘I think it is fair to say that New Zealand is one of the few places in the world where in our summer you can see an aurora wearing your shorts and jandals.
‘‘Not many people realise we’ve got this astounding thing down here in the south.’’
