Many lunar observers called the Full Moon at the tail end of August a Supermoon because it occurred less than a day from perigee when the Moon is closest and at its biggest in the sky. The Moon’s orbit is not a perfect circle. It’s an ellipse – an oval shape with the Earth closer to one end of the oval. When the Moon comes around that end of the oval and is closest to the Earth, it is called the perigee of its orbit. The farthest point is called the apogee. The full Moon this month is better than last month! It will be less than an hour from perigee and bigger than last month.
But wait! It gets even better. This month’s Full Harvest Moon will be eclipsed by the Earth’s shadow – a total lunar eclipse! Because the Moon’s orbit is tilted 5.1 degrees with respect to the Earth’s orbit, it usually passes below or above the Earth’s shadow – no eclipse. This eclipse should be the best of those seen in recent years. The eclipse occurs on the evening of September 27. The partial eclipse, when the Earth’s shadow first slices into the Moon, begins about 9:07 EDT with totality following at 10:11 EDT. Mid eclipse is at 10:48 and totality ends at 11:23 EDT. This is early enough for kids to get out and watch the Moon as it turns a nice shade of red – a blood Moon! The Moon will be closer to the centre of the Earth’s shadow during this eclipse and will, as a result last longer. Get out and see it! This will be the last eclipse visible in North America until January 31, 2018. Between now and then there will only be one partial eclipse to look forward to.
For you numbers freaks: Apogee this month is on the 14th and the Moon is 406,465 Km away at 07:28 EDT. Perigee occurs at 21:47 EDT on the 27th and the distance is 356,876 Km. The Sun sets about 19:30 EDT at the start of September and sets around 18:50 EDT by the end of the month. I think it’s time to make sure enough firewood has been set aside.
At dawn on the 10th, Mars, the crescent Moon and Venus shine low in the east. Look for the waxing Moon to be close below Saturn (3 degrees) in the southwest at evening twilight.
September 23rd at 16:21 marks the Fall Equinox – autumn has arrived.
From September 24th and for the next few early mornings watch for Mars less than 1 degree from the bright star Regulus. This pair will be about 10 degrees to the lower left of Venus.
The best excitement this month is the Total Lunar eclipse. The Moon should turn a nice blood red shade as the eclipse occurs. Don’t miss it, please! It’s a long wait until 2018 to see another.
The Beginner’s Observer’s Guide by Leo Enright is available at the Sharbot Lake Pharmacy or by contacting the Royal Astronomical Society of Canada www.rasc.ca/publications, subscriptions for our very own excellent Canadian astronomy magazine, Sky News, are also available from RASC..