Astronomers are worried that an increase in reports of people shining lasers at airplanes could lead to the government outlawing the pointers. "This has come up in other places in Canada," David Lane, a Halifax astronomer and president of the Royal Astronomical Society of Canada, said Tuesday.

"I think what often happens is people associate the use of these things with crazy amateur astronomers, but we’re the reasonable people. We’re not going to be stupid enough to shine them on an airplane. Unfortunately, it’s guilt by association."

Transport Canada recently expressed concerns about an increasing number of incidents where lasers were pointed at commercial planes in Canada. Since January 2009, there have been more than 100 incidents across the country. Three of those have occurred in Nova Scotia.

He said the association is trying to determine what the rules are for using lasers.

An astronomy association in Quebec using lasers near Dorval airport was told by Transport Canada more than a year ago that it needed government permission to use them, but that message hasn’t been passed to any other astronomy group in Canada, Mr. Lane said.

A Transport Canada website about lasers says it’s illegal to point them at an aircraft but doesn’t say they can’t be used at all.

"There are mixed messages from Transport Canada of what their (interpretation) of the law is," Mr. Lane said.

The lasers can’t cause permanent eye damage when momentarily shined in someone’s eyes but they can temporarily blind or disorient a pilot, which is dangerous, he said. It would be impossible to keep them shining directly into a pilot’s eyes long enough to cause damage, he added.

Mr. Lane said astronomers use the lasers to point out stars and constellations to youngsters and others, but they do so responsibly and not when planes are in the area. Losing the use of the lasers, if they are banned, wouldn’t be the end of the world for astronomers because they have only been around for the past 10 years, he said.

"It’s more of an annoyance because they’re a handy gadget for showing kids constellations. . . . It would be a shame to not have them because of a small number of irresponsible people with nothing more to do than shine them at aircraft."

The most recent incident in Nova Scotia happened on Jan. 9, when an Air Canada Jazz flight from Sydney to Halifax reported that a green laser was flashed into the cockpit after takeoff, when it was more than 1,300 metres high.

Prior to that, there were two incidents within three days in October. An Air Canada flight from Ottawa to Halifax on Oct. 11 reported seeing a green laser while approaching the airport at an altitude of 1,500 metres.

On Oct. 13, an ExpressJet Airlines flight from Newark to Halifax also reported a green light.

Both flights said the light seemed to be coming from the Halifax Harbour waterfront area.