This is the Dudley Observatory Skywatch Line for Wednesday, October 30th, and Thursday, October 31st, written by Louis Suarato.
Wednesday evening, Mercury and Venus will be 1 degree apart. Try to view the two innermost planets before they set at 6:32 p.m., and 6:46 p.m., in the west-southwest. The 9% illuminated, waxing crescent Moon, leads Jupiter and Saturn into the west-southwestern horizon. The Moon will set at 7:57p.m., followed by Jupiter at 8:20 p.m., and Saturn at 9:59 p.m.. The Moon and Jupiter are 9 degrees apart. Mars rises at 5:43 Thursday morning. The Moon returns to the sky 13% illuminated at 11:12 Thursday morning. At dusk, you’ll find the Moon 5 degrees to the upper left of Jupiter.
One of the brightest constellations in the autumn night sky is Pegasus, named after the winged horse from Greek mythology. Pegasus is one of the fall sky dominated constellations known as the Andromeda Group. Pegasus is the 7th largest of the 88 modern constellations, covering 1,121 square degrees. The asterism known as The Great Square of Pegasus, within this constellation, is comprised of the 2nd magnitude stars Markab, Scheat, Algenib, and Alpheratz. Alpheratz is in the neighboring Andromeda constellation. The Great Square encloses a relatively dark area making it the most prominent feature of the fall sky. A Messier object within Pegasus is the globular cluster M15. Discovered by Dominique Maraldi in 1746, M15 is one of the most compact globular clusters. At an age of 12 billion years, it is also one of the oldest globular clusters. M15 is 33,600 light-years away, and contains more than 100,000 stars. Look for Pegasus high above the eastern horizon before midnight, and look for M15 four degrees to the northwest of Epsilon Pegasi. Epsilom Pegasi is the hoof of the bent leg of the winged horse. M15 is 6th magnitude, and can be seen with medium sized telescopes.