A brilliant flash in the sky Tuesday night has people from St. John's to Bonavista wondering what they saw, even though local astronomers say it was likely a lightning strike.

There were several reports of a flash that turned the sky a brilliant white or blue before it faded to pink. Some witnesses say they saw a couple of flashes, others only one.

Former city councillor Marie White saw the flash as she was driving to a meeting around 9 p.m.

"I was moving through the intersection. Off to the right there was a brilliant flash of light, just like an explosion went off in front of my face. And it lasted about 20 seconds," she said.

While witnesses have suggested it could be a comet, a meteor or satellite debris, it was probably lightning according to Chris Stevenson, a physics professor at Memorial University in St. John's.

Cloud-to-cloud lightning may explain phenomenon

"I'd say the most likely explanation is, as boring as it may sound, is high altitude lightning. So far we're being missed by the satellite bits and the asteroid bits and so on and so forth. At least I don't want to get hit by these things," he said.

Stevenson said he has checked with other local astronomers and they agree it was probably lightning.

"Lightning does discharge from cloud to cloud, and there are other discharges that actually go upwards, called 'sprites' … they happen in the upper atmosphere, and these things can pack quite a wallop," he said.

White disagrees with Stevenson's assessment, saying the flash didn't look like any lightning she had ever seen.

"Whether it was the jagged single lightning, even the lightning I've seen that's lit all of the sky, it didn't resemble that. It was too powerful. Just like this big flash of white light," she said.