Let’s hope that the sky will be clear on Saturday noon since a solar eclipse will take place above Quebec. The eclipse, which must be observed with protective glasses equipped with an appropriate filter, will however be partial in the Montreal region.
The most impressive phenomenon, which will be visible on Saturday from the Pacific to the Atlantic in a narrow strip about 200 km wide, is an annular eclipse. The latter occurs when the Sun, Moon and Earth are aligned on the same axis. This particular arrangement ensures that the Moon, which is illuminated by the Sun, becomes a screen for us, Earthlings, when we look at the Sun. This eclipse occurs when the Moon is at the furthest point in its orbit from Earth. Its apparent diameter is then smaller and does not hide the entire surface of the Sun. A thin ring of solar light thus remains visible all around the Moon, explains Marie-Eve Naud, astrophysicist at the Trottier Institute for Research on Exoplanets, at the University of Montreal.
On the other hand, when the Moon is closer to the Earth, its size appears larger to us, which allows it to hide the entire surface of the Sun. We then speak of a total eclipse, because the Sun completely disappears for a period of up to seven minutes.
We speak of partial eclipses when we are geographically far from the place where the total or annular eclipse is visible. We also call partial eclipses the phases where the Moon begins to veil the Sun, until it completely covers it, and when it withdraws.
“To see the ring [lumineux autour de la Lune, lors de l’éclipse annulaire de samedi 14 octobre], you will have to be in the center of this narrow strip which will cross Oregon, Nevada, Utah, New Mexico, Arizona, Colorado and Texas, then the Yucatán Peninsula, Belize, Honduras , Nicaragua, the coast of Costa Rica, Panama, Colombia and finally Brazil. This band of annularity is the area where the shadow cast by the Moon on the Earth will move. Because given that the Moon revolves around the Earth, its shadow moves along a narrow band,” explains Marie-Eve Naud.
“In southern Quebec, we will therefore find ourselves very far from this band of annularity,” she points out. This is why we will rather witness a partial eclipse, in Montreal, only 17% of the solar disk will be obscured at the highest point of the eclipse, and even less as we find ourselves further north and further east. East. On the other hand, in Vancouver, approximately 82% of the Sun’s surface will be hidden at the highest point of the eclipse.
In Montreal, the partial eclipse will begin at 12:11 p.m. and reach its maximum at 1:17 p.m. It will end at 2:23 p.m.
It is absolutely essential to have protection when observing a solar eclipse, whether total, annular or partial. If you can’t get your hands on glasses equipped with a filter that blocks 99.9% of the harmful rays emitted by the Sun, you can concoct a device using a shoebox that allows for “eye-hole” projection. pin “.
“We should never stare at the Sun, because solar radiation is so powerful that it can damage our eyes. We can even go blind,” warns Mme Naud.
It will also be possible to observe Saturday’s eclipse at the Space for Life Planetarium, as well as on the MIL campus of the University of Montreal.