Skywatch Line for Monday and Tuesday June 17th and 18th, written by Joe Slomka
This is the Dudley Observatory’s Skywatch Line for Monday and Tuesday June 17th and 18th, written by Joe Slomka.
The Sun sets at 8:36 PM; night falls at 10:54. Dawn begins at 3:00 AM and ends with Sunrise at 5:17. Solstice takes place on the 20th at 4:51 PM. From then on, days become shorter.
Libra includes the Moon on both nights. Monday’s Moon set at 2:11 AM and rises at 4:26 PM; by 9 PM will be 29high in the South, appears 30 arc-minutes in size, 84% illuminated. Tuesday’s Moon sets 2:33 AM, rises at 5:34 PM, by 9 PM, it’s 30 arc-minutes in the South, 22° high and sets at 3 AM, Wednesday.
Minor planet 2Pallas is located in Corona Borealis, rising at 3:21 PM, by 9 PM it is 58° high in the East, 9th magnitude, 0.3 arc-seconds in size, 98% lit and sets at 7:07 AM. It is the second minor planet to be discovered, by Wilhelm Olbers (of comet fame) in March 1802; the third largest, it is about 502KM (312mi) and named for the Greek goddess of Wisdom.
Mercury and Venus are not present, hidden by solar glare. As usual, Saturn is first to rise, in Aquarius at 12:57 AM, 1st magnitude and 17 arc-seconds; by 4 AM it lies 30° high in the Southeast and sets at 12:09 PM. Neptune is next, 10° behind Saturn in Pisces, 8th magnitude, 2 arc-seconds, rises at 1:17 AM, 29° high and sets at 1:05 PM. Mars is 37° East of Neptune, in Aries, 1st magnitude, 5 arc-seconds, rises at 2:39 AM and 15° high. Eastern Taurus encloses Uranus and Jupiter. Uranus trails Mars by 18°, rises at 3:28 AM, 5th magnitude, 3 arc-seconds, 6° high and sets at 5:52 PM. Finally, Jupiter emerges just inside the horizon, only 22° from the Sun, rises in Dawn at 4:03 AM, minus 2nd magnitude, 33 arc-seconds, by 5 AM 10° high and sets at 6:42 PM.
All these planets set during daytime and are either 100% illuminated or very close to “full”.
Recent discoveries increased the total of moons orbiting our planets. Uranus comprises a total of 28 moons, the newest is 8KM (5 mi) in size and takes 680 days to orbit. Neptune enlarged its collection to 16 moons, the newest is 23KM across (14mi) and takes 9 years to orbit, the other is 14KM (8mi) diameter and requires 23 years to circumnavigate. The total for all moons now is 289.
Clear Skies Joe Slomka