This is the Dudley Observatory’s Skywatch Line for Monday and Tuesday, August 31th and September 1st, written by Joe Slomka.
The Sun sets at 7:31 PM; night falls at 9:11. Dawn begins at 4:40 AM and ends with the Sun rising at 6:21.
Monday’s Moon rises at 7:14 PM in Capricornus, 98% illuminated and sets at 5:25 AM, Tuesday. Tuesday’s Full “Corn” Moon rises at 7:43 PM in Aquarius and sets at 6:29 AM, Wednesday.
Sagittarius continues to house Jupiter, Saturn and Pluto. Jupiter is the first to rise at 5 PM, glaring with minus 2nd magnitude, 44 arc-seconds in size, is best observed at 9:28 PM and sets at 2 AM. Telescopic observers can see the Great Red Spot (a giant earth-sized storm) at 11:10 PM and also see Jovian moon Ganymede disappear at 8:34 PM and reappear at 11 PM. Both events take place Monday evening. During September, Jupiter dims and shrinks a little in our telescopes. Pluto rises next at 5:22 PM, glows with 14th magnitude, appears as a tiny dot (requiring detailed sky charts), 11° high and sets at 2:23 AM.
Saturn is next, rising at 5:29 PM, zero magnitude, 17 arc-seconds, and best observed at 10:03 PM and sets at 2:42 AM. It’s beautiful ring system is tipped 23°. Both Jupiter and Saturn are perfectly situated for your enjoyment.
Aquarius houses Ceres and Neptune. Minor Planet 1Ceres rises at 8:38 PM, shining with 7th magnitude; 11° high, it is best observed at 1:05 AM and sets during Dawn. Monday evening, it lies above the bright star Fomalhaut and below the Moon. Neptune rises at 7:55 PM, gleaming with 7th magnitude, 2 arc-seconds, is best seen at 1:39 AM, 41° high and sets daytime.
Uranus, in Aries, rises at 9:50 PM, shines with 5th magnitude, 3 arc-seconds in size, is best observed at 4:48 AM and also sets daytime. Charts for Neptune, Ceres and Uranus are available from astronomical media.
Red Planet Mars rises in Pisces at 9:36 PM, twinkles with minus 1st magnitude, 19 arc-seconds, 91% lit and is best observed at 4:03 AM. Mars continues to brighten in September, from minus 1.8 to minus 2.5 magnitude and increasing in size from 19 arc-seconds to 22 arc-seconds.
Finally, Venus rises in Gemini at 2:38 AM. September, Venus shrinks from 19 arc-seconds to 15 arc-seconds, but goes from 60% to 71% lit; it blazes with minus 4th magnitude and sims slightly.
If we look south at about 10:00 PM, a hazy white band of light seems to stretch from the North Pole to horizon. This band is commonly called “The Milky Way”. Examination of the Milky Way with binoculars or telescopes reveals it to be a continuous band of stars or clouds of dust or gases. Our galaxy is a gigantic pinwheel, with several arms. Our planet is located in one of these arms. When we look at the Milky Way, we are seeing through this arm out into space. From Lyra to Sagittarius the Milky Way seems to divide in two. A giant dust cloud causes this “Great Rift”. We can see these dust clouds on other galaxies. If we follow the Milky Way to the horizon, we come upon the constellation Sagittarius. The center of our galaxy is located in that constellation, but we cannot see it due to dense star and dust clouds.