Surely the most eagerly awaited astronomical event in years, the total solar eclipse on August 21 deserves our full attention this month.
Partial solar eclipse in Quebec
A total solar eclipse is an extraordinary event, but to see this one live, you must head to the United States. The eclipse is truly total only within the path of totality, a corridor at most 115 kilometres wide crossing the U.S. from Oregon in the northwest to South Carolina in the southeast. For observers along this path, the length of totality varies from 2 minutes on the west coast to just over 2 minutes 30 seconds on the east coast with a maximum of 2 minutes 40 seconds in Illinois. Note that observers in these areas can also see the partial phases of the eclipse.
On either side of the path of totality, the Moon doesn’t fully block the Sun. A partial solar eclipse therefore occurs in the rest of the U.S. and in Canada and Central America. The timing and length of the phenomenon, as well as the maximum percentage of the solar surface covered by the Moon, vary depending on the location.
Throughout Quebec, the phenomenon takes place in mid-afternoon. For the southern part of the province, nearly 60% of the solar surface will be obscured at the maximum phase of the eclipse, compared with barely 25% for the northernmost part of Quebec. Weather statistics for the province aren’t very promising with just a 50-50 chance for clear skies on August 21. Even if the sky is partly cloudy, though, you can watch the eclipse unfold during the occasional clear moments because the phenomenon lasts a long time. (During a total eclipse, however, the maximum phase lasts only a few minutes, so clear skies are even more crucial.) But if you want to see the phenomenon from beginning to end, you’ll need to travel at short notice to locations where weather conditions are best.
In Montreal, the partial eclipse begins at 1:21:54 p.m. EDT and reaches its peak at 2:38:26 p.m. when 58.3% of the solar surface is obscured. The phenomenon ends at 3:50:24 p.m.
Visit espacepourlavie.ca/en/eclipse2017 for details on the phenomenon, eclipse times for other cities across Québec and elsewhere in Canada, and tips for observing it safely and enjoyably.
Protect your eyes
We can’t stress enough that staring directly at the Sun is dangerous. Without a proper filter, the intense light from the Sun, even in a partial eclipse, can quickly cause permanent damage to your retina. Sunglasses, colour film negatives and smoked glass are not adequate filters. Instead opt for filters specially designed for safely observing the Sun.
You don’t have the right filter? Our Planetarium’s astronomers suggest projecting an image of the Sun onto a white surface so that several people can observe the partial eclipse at the same time. Different methods are possible (using a pair of binoculars, an astronomical instrument or a mirror), but never leave your equipment unattended. Alternatively, consider attending one of the public events held on the afternoon of August 21 by various planetariums, museums and clubs for amateur astronomers. Specialists will be on hand to ensure a safe, unforgettable group experience. The eclipse will also be broadcast on television, the web and many digital platforms, though nothing beats seeing this amazing phenomenon live with your own eyes.
Set aside the afternoon of Monday, August 21 and mark “partial solar eclipse” on your calendar.
The Perseids
As a cosmic appetizer before the partial solar eclipse, the Perseid meteor shower is back this year and hits its peak on the nights of August 11-12 and 12-13. Unfortunately, the waning gibbous Moon, visible in the second half of the night, will impede your view. Only the brightest meteors will be visible among the stars, so don’t expect to see more than a dozen Perseids an hour in a perfectly clear sky.
This meteor swarm is caused by the periodic comet Swift-Tuttle. Every year, Earth passes very close to the comet’s orbit. The comet leaves dust particles in its wake, and these create the famous meteor shower.
The summer planets
Jupiter and Saturn are visible in the early evening during August. As for Venus, it can be seen early in the morning before sunrise.
Look for Jupiter shortly after sunset not very high on the southwest horizon. The crescent Moon flanks it on the evenings of August 24 and 25. The gibbous Moon lies very near Saturn on the evening of August 2 and can help you spot the ringed wonder, which shines to the south between the constellations Sagittarius and Scorpius. The Moon passes by Saturn again late in the month on the evenings of August 29 and 30. There’s no missing Venus, which shines brilliantly to the east in the colourful dawn sky around 5 a.m. A thin crescent Moon is visible near the dazzling planet on the morning of August 18.
Finally, note that a partial (and unspectacular) lunar eclipse occurs on the night of August 7. It’s visible in Central Asia and the Indian Ocean.
Clear skies!
