Observing the Moon 11/8
Friday, November 8 finds the Moon a 5.6-day-old waning crescent, as it approaches its First Quarter phase on Saturday. Since the Moon dominates the sky for nearly the first half of the night, let's pick out a few interesting features, and draw them at the eyepiece.
Yes, I'm recommending you add a pencil and pad of paper to your observing gear! The more you draw, the more you see, the better observer you become, and the easier it becomes to draw at the eyepiece.
The drawings needn't be professional, but simply "impressions" of what is seen. Give it a shot!
Tonight, let's visit challenging Rima Manelaus and easy Crater Delambre.
This is a rille network from the Moon's Imbrian period (From -3.85 billions years to -3.2 billions years). It is 85.0 x 1.0 miles in size and best viewed six days after New Moon or five days after Full Moon. You'll need a 12" reflector for this target.
Located at 17.0° east longitude and 17.0° north latitude, in the southeast part of Mare Serenitatis.
The name Rilles of Menelaus is given for the 1st century BC Greek mathematician and astronomer.
This crater from the Upper Imbrian period (from -3.8 billions years to -3.2 billions years) is a round 32.0x32.0 miles in size. It rises as high as 15,000 feet.
The steep slopes of Crater Delambre support smaller craters along its western edge, and along its steep terraces on the inner portion. Note the rugged floor, and numerous cracks and craterlets. Observe this target in a 50 mm refractor.
Located at 17.5° east longitude and 1.9° south, The crater is named after an 18th century French Astronomer that collaborated with the famous astronomer Méchain.
Observing the Moon 11/9
Saturday, November 9 is a true First Quarter Moon; literally half way through the lunar cycle. The Moon will now leave its crescent phase and become gibbous.
Many people mistakenly think the First Quarter Moon is half as bright as a full moon, but it is only one-eleventh as bright because of the many shadows during the quarter phase - a Full Moon casts no shadows. First Quarter is also brighter than third quarter.
Tonight let's use those shadows to see some fine details.
Dorsa Smirnov is a wrinkle ridge from the Imbrian period (From -3.85 billions years to -3.2 billions years).
It is comprised of a system of wrinkle ridges running north-south. Its dimensions are 79.0 x 12.0 miles. The craterlet Very sites on its central part. A 50 mm refractor will be good for this target.
Find it a Longitude: 25.0° East and Latitude: 25.0° North in the South-East part of Mare Serenitatis
It is named for Serguej S. Smirnov, a 20th century soviet Naturalist born in U.S.S.R.
Rima Hyginus is from the Imbrian geological period (3.85 billions years to 3.2 billions years), and is 133 x 2.0 miles in size. It is a large rille running southeast to northwest and crosses the crater Hyginus, at which point it turns west.
It appears to be formed from a series of small craters. You'll need an 8" reflector for this one.
It is located northeast of the Mare Tranquillitatis area.
Rima Hyginus is named for Caius Julius Hyginus, a second century BC Greek born astronomer.
Lunar maps and some descriptions courtesy of The Virtual Moon Atlas. Lunar images courtesy of The Consolidated Lunar Atlas.
Mark Wagner is a life-long astronomy enthusiast and deep sky observer. He has spent the past twenty years popularizing amateur astronomy in the San Francisco bay area through his writing and community building. A past president of the San Jose Astronomical Association, he founded what is now the annual Golden State Star Party in California. Please post if you have comments, questions, sketches or images you've taken of the targets mentioned above.