An expert at Auckland's Stardome has weighed in on reports of a bright light shooting across the skies over New Zealand last night.

Callers to Newstalk ZB described a "ball of fire" in the sky south-west of New Plymouth.

Some people posted on social media about seeing the sky light up, while others described the light as being green in colour.

Stardome public programmes team leader Pooja Sundar said meteors tend to be metallic.


"They're bits of rockets that have been left up in space or just chunks of asteroids, they're usually quite small.

"When it's still in space it's a meteoroid, it becomes a meteor when it's in the earth's atmosphere and that's when you see the really bright light when it's burning up, its going pretty fast and its burning up.

"The colour of the light depends on what its made of. A lot of the meteorites we get tend to be iron, and thats a nice yellow light. If it's another metallic substance it can be a blue-green light or a green one some can even be violet."

There has been speculation that the bright object was part of a Russian rocket re-entering the Earth's atmosphere, and Sundar noted that "anything's a possibility" to explain what the "ball of fire" was.

"If there was any left over debris it may be a rocket, but I couldn't really say."

Meteors pass by the earth every day. Sometimes they enter our atmosphere with dramatic effects

She said reports of sightings like this one were common worldwide.

"All over the world you get a few thousand a year, they're reported all the time, however actually seeing one in New Zealand... I haven't seen that many so it's always really exciting when you get to see one."

One woman posted on Facebook that she saw the light in Lower Hutt.

"Yup saw it clearly in Lower Hutt. It was huge and the tail colorful."

Other eyewitnesses reported sightings in Blenheim, Porirua, Lake Ferry, Martinborough and Dunedin.