And more may appear tomorrow night.
University of Otago physics Professor Craig Rodger said the colourful phenomenon was caused by coronal mass ejections (CMEs) - explosions of plasma from the sun that are shot into space.
Auroras are formed when charged particles from the CMEs collide with gases like oxygen and nitrogen in Earth's atmosphere, causing them to release energy in the form of light which creates the colourful displays over head.
The onset of the severe geomagnetic storm also had the potential to affect power transmission lines, so Transpower has issued a grid emergency notice this afternoon and removed some South Island electricity transmission lines from service.
"Removing the circuits from service does not have any impact on consumers’ electricity supply but is an important step to prevent damage to critical equipment, should the solar storm get worse," a Transpower spokesman said.
Prof Rodger said the storm appeared to be continuing and another coronal mass ejection was on its way toward Earth, so it was possible more Aurora Australis would be seen on Thursday night, if the skies remained clear.
‘‘If you're interested in the Aurora, this is definitely the time to go out and be looking for it.’’
In a Facebook post late this afternoon, Civil Defence said the National Emergency Management Agency was monitoring the large ejections of energy from the sun.
"We are working with international and domestic experts, who agree this event is unlikely to result in significant impacts for New Zealand."
Civil Defence said space weather was linked to solar activity, which rises and falls across an 11-year cycle. The current ‘solar maximum’ (a period of high solar activity) began in October 2024 and increased solar activity was expected over the next few years.
