An aurora is due to light up the night sky on Saturday evening, though astronomers warn forecast cloudy weather could stand between stargazers and the colourful display.
A large solar flare erupted on the sun on Friday throwing off a cloudof gas, which is heading for earth, causing the aurora.
Mt John Observatory astronomer Alan Gilmore says stargazers should start looking up at the sky about one hour after sunset.
A weak aurora will appear as a pale glow in the sky, but if it is stronger it will show up as white, or with red-coloured rays.
"If it gets really active it forms what looks like a curtain which is greenish-white at the and then becomes red at the top," says Mr Gilmore, the resident astronomer at the Tekapo observatory.
People in the South Island and in rural areas, stand the best chance of seeing the display.