Skywatch Line for Monday and Tuesday October 16th, and 17th, 2023

This is the Dudley Observatory’s Skywatch Line for Monday and Tuesday October 16th, and 17th, written by Joe Slomka.

The Sun sets at 6:12 PM; night falls at 7:46. Dawn begins at 5:37 AM and ends with the Sun rising at 7:11.

Monday’s 2-day-old Moon resides in southwestern Libra, 30 arc-seconds in size and 5% illuminated, rises at 9:08 AM, bright minus 3rd magnitude and sets at 7:01 PM.  Tuesday’s Moon shifts to southwestern Scorpius, rising at 10:18 AM, 4° high at 7 PM, same size, but 10% lit and minus 5th magnitude and sets at 7:31 PM; observers can try at about 7:20 PM to see a slightly larger crescent. Both Moons are very low to the horizon, so the observer should find a clear southwestern horizon and begin observing about 6:45 PM to see the very young crescent.

Mercury and Mars continue to be hidden by the Sun’s glare. Saturn continues to inhabit Aquarius, already risen in the Southeast, glimmering with zero magnitude, 18 arc-seconds, highest at 9:27 PM, 30° high at 8 PM and sets at 2:41 PM. Neptune, in Pisces, lies 25° behind Saturn, shining with 7th magnitude, 2 arc-seconds, 29° high at 8 PM, 39° highest at 10:58 PM and sets at 4:50 AM.

Eastern Aries houses Jupiter and Neptune. Gas Giant Jupiter is the brightest evening planet. It rises at 7:02 PM, radiates with minus 2nd magnitude, appears a large 49 arc-seconds, 10° high at 8 PM, highest at 1:59 AM and 30° high in the West at 6 AM. On Tuesday night, telescopic observers can witness the Great Red Spot (a giant storm) march across the planet at 1:27 AM, Europa’s Shadow follows at 2:46, Europa itself at 3:43, Europa’s Shadow ends at 5:06, Europa ends a 5:55 AM and the Great Red Spot reappears at 9:18 PM. Uranus trails 9° behind Jupiter, rising at 7:23 PM, 5th magnitude, 3 arc-seconds, 6° at 8 PM, 65° highest at 2:25 AM and 39° high in the West at 6 AM.

Eastern Venus is the “Morning Star”. It rises at 3:16 AM, blazes with minus 4th magnitude, 26 arc-seconds, and is 29° high at 6 AM. It is 46° from the Sun; take care not to look at the Sun without special glasses.

Comet 103P/Hartley accompanies Gemini. It rises at 11:55 PM, 8th magnitude, 68% lit, 11° below Pollux and 61° high. The comet was discovered by Australian Malcom Hartley in 1986. The comet came closest to Earth on September 26 and will be nearest to the Sun at November 12th; it orbits between Mars and Jupiter every 6.5 years. Suggested best views are predicted between 1 AM and Dawn.