Astronomer David Lane, director of the observatory at Saint Mary's University in Halifax, said it was likely a bright meteor called a fireball.
He said that while they are not rare, they do usually pass by in the middle of the night when most people are sleeping.
The ball of fire was reportedly seen by people in the Annapolis Valley, Antigonish, Sydney and even some on Prince Edward Island.
"It grew brighter as it streaked low on the southeastern horizon and expired with a bright green flash," said Emily MacKay on Twitter
Nova Scotia Webcams captured the fireball on its Halifax harbour webcam.
After multiple fireball sightings last year, Lane told CBC the odds of finding a meteorite after seeing a fireball are small.
"The chances of finding it are pretty slim. You really need a lot of good camera reports that shows the streak in the sky so that scientists can follow up ... to do, essentially, a triangulation and pinpoint a target search area."
He said finding a meteorite is very rare. Only one meteorite has ever been confirmed to have been found in the Maritimes.
"Fireballs happen all the time," Lane said. "There's something like 100 tonnes of stuff that hits the Earth every day from space, but [in] Nova Scotia, or I should say the Maritimes, there's only been one meteorite ever found on the ground."
Nova Scotia Webcams caught the thing on camera:
....the increases in fireball numbers are not just due to improved reporting - I suspect they are to some extent - then the above chart is quite worrisome. It does however seem to be plateauing which has to be good news although this is hardly clear when data is presented on a yearly rather than a monthly basis. It would be instructive if the data could be broken down into smaller time slots.