Canadians ready to take in partial eclipse of the sun
File-In this Jan.15,2010 file photo showing a combination of three separate photographs, the various stages of an annular solar eclipse seen over Anuradhapura, Sri Lanka. An annular solar eclipse occurs when the moon blots out all but a ring around the sun. This year's solar show can be viewed from eastern Asia to parts of North America.
Published Friday, May 18, 2012 9:17AM EDT
TORONTO - A celestial spectacle will trace a path across much of Canada this long weekend.
Canucks living west of the St. Lawrence will be able to see a chunk of the sun blotted out by the moon on Sunday as a partial solar eclipse takes place.
The event will begin across the globe in eastern Asia, where, weather permitting, early risers in southern China, northern Taiwan, and southeast Japan will be able to take in the solar spectacle early on Monday morning.
Parts of Canada and the western U.S. will be able to take in the show before sundown on Sunday.
For those in parts of the southwestern United States, a glowing halo will appear as the moon moves right in front of the sun in what's technically called an annular eclipse.
Further north, Canadians won't be able to see that "ring of fire," but will still get to take in an event that doesn't happen all that often.
"What we're going to have is just a partial eclipse, so instead of that ring, it will be almost like a chunk bit out of the sun," explains Trevor Prentice, a staff scientist at the Telus World of Science in Edmonton.
"It's like a crescent moon, but a crescent sun in this case."
The centre, like many others across much of central and western Canada, will be holding an eclipse viewing party of sorts where experts and the right viewing equipment will be on hand.
"It's a really cool astronomical event to watch. We're not used to seeing the sun that way with part of it obscured," Prentice says.
"It spurs people's imagination, gets them interested in astronomy in general so maybe they can have an interest in looking at other cool things up in the sky."
Before looking skyward however, experts are warning Canadians to make sure they view the eclipse only with the right equipment.
"You should never look at the sun directly, even if it is eclipsed," says Prentice. "It can damage your eyes and create permanent blindness or, in the best case scenario, you might an image of the sun on your retina for the rest of your life."
Regular sunglasses, smoked glass, exposed photographic film, dark garbage bags and binoculars or telescopes without proper filters will not protect eyes during a solar eclipse and are unsafe to use.
Special metal coated solar viewing glasses, which are being handed out by some observatories or are on sale at many science centres, are a safe way to watch the partial eclipse.
Number 14 welding filter glass can also be used to take in the event safely as the dark green glass filters out much of the visible light and all of the harmful invisible radiation. It can be obtained from most welding supply stores.
Those with a telescope or binoculars can obtain solar filters they can place at the front of their equipment before the light enters the device.
And for those who can't get their hands on any of that equipment, a simple home-made solution is available as well. A pinhole camera can be created with two pieces of white cardboard by cutting a small hole in the middle of one and covering it with aluminium foil. After pricking a tiny hole in the foil and facing away from the sun, the two pieces of cardboard can be held up so the sun's image shines through the pinhole onto the other sheet.
Just how much an eclipse a Canadian is able to watch will depend on where they are situated.
Those in much of British Columbia and Alberta will be able to witness more than 50 per cent of the sun covered by a wide arc of the moon's shadow, says Eric Briggs, secretary at the Toronto chapter of the Royal Astronomical Society of Canada.
Someone in Montreal, however, might just be able to glimpse a tiny bite taken out of the sun just as it sets across the horizon. Torontonians will be able to see about 10 per cent of the sun blotted out at dusk.
"It will look more interesting the further west you get," Briggs says. "You see sort of a semi-circular wedge taken out of the sun."
The last time many Canadians took in a similar event was in May 1994, when an annular eclipse tracked a path over part of the country, says Briggs.
"These eclipses repeat every 18 years and 10 and a bit days," he says.
Canadians who do get their hands on safe solar viewing equipment would do well to hold on to it as another celestial event takes place a few days after the eclipse.
Called the "Transit of Venus," the event takes place on June 5th.
"That's a much rarer event when the planet Venus is silhouetted against the sun," Briggs explains.
Venus' shadow will appear as a tiny dot traversing the solar surface. Such transits occur in pairs, with the 2012 transit succeeding its earlier partner, which took place in June 2004.
The next pair of transits are expected to take place in December 2117 and December 2125.