The Carter Observatory is asking people who saw lights in the sky overnight on Tuesday to log their sighting to help determine whether it was a meteor or space junk.
The Wellington observatory has received a large number of reports from Auckland to the lower North Island of a display of green, white, orange and yellow lights just after 11pm on Tuesday.
Nelson residents also reported sightings to police.
The observatory says the object made a sonic boom as it passed through Earth's atmosphere.
It says the object travelled south to north up the country, indicating it could be space junk, as meteorites usually travel east to west.
People who saw the lights, or filmed them, are asked to fill in a fireball report on the Royal Astronomical Society's website.
