There’s a headline that will raise the hackles of many an astronomer. But on the evening of September 27, 2015 even the most rigorous observers will agree: Heavenly bodies will indeed align producing the best total lunar eclipse of the decade! The eclipse will be visible in its entirety throughout Quebec, starting early in the evening… and all this, during the largest full moon of the year. Will you be on hand to see it?
An eclipse of what?
A lunar eclipse occurs when the full moon, which is normally illuminated by the Sun, moves through Earth’s shadow and seems to almost vanish from the sky.
But if you were standing on the Moon during the eclipse, what would you see? Above you, the blinding solar glare would blast the lunar surface with light. The Sun would gradually move westward and slip behind the Earth, which would appear 4 times larger than the Sun in the lunar sky. At first, the Sun would be partially hidden by our planet and the lunar surface around you would gradually grow darker. At that point, you would be immersed in Earth’s penumbra.
Next, something amazing would happen. As the Earth begins to hide the Sun completely, sunset colours, created by our planet, would be cast on the Moon. And just like during a sunset on Earth, both the Sun and Earth’s atmosphere would become reddish-orange, due to the diffusion of light by atmospheric gases. Even after the Sun is totally hidden by Earth, you and the lunar surface around you would still be bathed in the reddish tinge of sunset, illuminated by a thin ring of sunlight, reddened by its passage through the atmosphere.
Eventually, the first direct beams of sunlight would slowly reappear on the other side of the Earth, but it would take over an hour for the Sun’s disk to no longer be eclipsed.
How and when to observe the eclipse
On September 27, all of the lunar eclipse stages will be visible throughout Quebec too. The event will begin in the southeast at 8:11 P.M. (Eastern Daylight Time) as the upper left part of the Moon enters Earth’s penumbra. A bit less than an hour later, the show will become much more evident and spectacular. At 9:07 P.M., the same part of the Moon will begin to enter Earth’s umbra. Then from 10:11 to 11:23 P.M., for 72 minutes, the Moon will be totally eclipsed by Earth’s shadow. This is when the reddish tint caused by Earth’s atmosphere is most obvious. The Moon will then gradually exit the umbra, with partial phases lasting until 00:27 A.M., and leave the penumbra nearly an hour later.
Lunar eclipses are both easy and fascinating to observe. They don’t present any danger to the eyes; and it isn’t necessary to travel to the country, to escape from city lights. Even if the weather doesn’t cooperate at first, the eclipse’s long duration allows the possibly of seeing the event later should the sky clear. Of course, if you absolutely want to see the eclipse, you’ll have to leave any clouds behind. There are lots of destination choices because the eclipse will be visible throughout North America, as well as Western Europe and Africa. You can even watch the eclipse through a window from the comfort of your bed! But why not take full advantage of the mild September evenings; you can even take your blanket outside with you. Most importantly, don’t miss this opportunity because the next total lunar eclipse won’t be visible in its entirety from Quebec until January 2019!
A “super” eclipse
This September’s eclipse is special in another regard: It will occur while the Moon is at perigee, which is to say, the closest point to Earth on its elliptical orbit. The Moon reaches perigee every month, but only once or twice a year when the Moon is full. It’s what some have dubbed a “supermoon.” This time, the Moon will appear 13 % larger than it did during the last eclipse, which will add somewhat to the spectacle. But the real obvious effect of this lunar “coincidence” will be on the tides. Since tides are most prominent during new and full moon, we can expect exceptional sea levels from September 28 to 30.
The planets belong to early risers
September provides the last opportunity of the year to see Saturn in the evening. Saturn is easiest to spot at the beginning of the month. Look for it low on the southwest horizon at nightfall, close to the red star Antares, in Scorpius. On September 18, the crescent moon will be less than 3 degrees to the right of the ringed planet.
But it’s in the morning sky that things are really happening—in preparation for the October conjunctions of Venus, Mars and Jupiter. Sulfurous Venus blazes on the eastern horizon, reaching its maximum magnitude on the morning of September 19. It will shine dozens of times brighter than any star. On the evenings surrounding September 24, not far to the left of Venus, Mars crosses paths with the star Regulus, in Leo. During this period, Jupiter resurfaces at dawn after spending a brief hiatus behind the Sun. The giant planet will approach Mars at month’s end.