An aurora is expected to be visible from the southern parts of New Zealand this evening.
The aurora was caused by a large solar flare on the sun yesterday, which has thrown off a cloud of gas.
Mt John Observatory astronomer Alan Gilmore said a dark rural sky with a low southern skyline was best place to view the aurora.
"The aurora is quite a faint glow and suburban lights will be a big disadvantage," he said.
The aurora appears as a white, or greenish-white glow in the sky.
"It looks a bit like a twilight glow when it is starting off near the horizon and it is usually a white colour.
"If it develops and extends higher the top can become a pinkish red," he said.
"If it becomes really active you get a sort of drapery, which is red at the top and has this greenish-white light at the bottom," he said.
Carter Observatory said on its Facebook page that the aurora is moving faster than originally thought.
It is expected to be visible from about 9pm local time tonight.
NZN