Skywatch Line for Monday and Tuesday October 30th, and 31st, 2023
This is the Dudley Observatory’s Skywatch Line for Monday and Tuesday October 30th, and 31st, written by Joe Slomka.
The Sun sets at 5:51 PM; night falls at 7:26. Dawn begins at 5:52 AM and ends with the Sun rising at 7:28.
Northeastern Taurus displays the Moon on both nights. Monday’s 17-day-old rises at 6:48 PM, 6° high at 7:30, 31 arc-seconds in size 94% illuminated, highest at 1:50 AM on Tuesday and sets at 10:50 AM. Tuesday’s Moon rises at 7:30 PM, 31 arc-seconds, 88° high, highest at 2:45 AM Wednesday and sets at 11:57 AM.
Mercury and Mars are still too close to the Sun. Southeastern Saturn remains the first planet to rise and be seen; it is already visible after sunset, shines with zero magnitude, 17 arc-seconds, 33° highest at 8:31 PM and sets at 1:44 AM. Neptune follows 24° behind Saturn, already risen, glows with 7th magnitude, 2 arc-seconds, 32° at 7:30 PM, 44° highest at 10:02 PM and sets at 3:54 AM.
Jupiter and Uranus share eastern Aries. Jupiter rises at 6:02 PM, sparkling with minus 2nd magnitude, a large 49 arc-seconds, 16° high at 7:30 PM, 61° highest at 12:57 AM and sets at 7:48 AM. On Monday, Jovian moon Ganymede begins eclipse at 7:42 PM and ends at 9:42. Tuesday’s Great Red Spot (a giant storm) starts at 2:58 AM, terminating during sunrise; it again begins at 10:49 PM, concluding during daytime. Uranus follows 10° after Jupiter, rising at 6:26 PM, shining with 5th magnitude, 3 arc-seconds, 11° at 7:30 PM, 65° high at 1:38 AM, setting during daytime.
Venus, located in eastern Leo, rises at 3:30 AM, blazing with minus 2nd magnitude, 22 arc-seconds, and 16° at 5:30 AM.
Comet 103P/Hartley now occupies southern Hydra, rising at 12:19 AM, 43° highest at 4:27 AM, appearing 71% lit, but dimming with 9th magnitude.
By midnight, Orion is already high in the southeastern sky. The bright white star Rigel marks the mighty hunter’s knee. A dim line of stars begins at Rigel and flows westward and downward, disappearing below the horizon. This is the river Eridanus. To see the full extent, one must travel to Florida. There Eridanus ends with the bright star Achernar, which means, “star at the river’s end.” Identity of this stream is a bit of a mystery. Ancient authors differ as to whether it refers to the Euphrates or Nile. Both rivers were revered from time immemorial. Both were sources of water and bountiful harvests. It is no coincidence that all the great civilizations and cities were founded along the banks of celebrated rivers. Ancients thought of the Earth as sort of an island surrounded by a great body of water. The creation story in the Book of Genesis alludes to this view, as do Babylonian myths. The sky bears out this vision. For the past several months we have been observing water related constellations: Delphinus, the Dolphin, and Capricornus, the Sea Goat, began the procession, followed by Aquarius, Cetus and Pisces. Eridanus spills its heavenly waters to sustain this celestial aquarium.