This is the Skywatch Line for Monday and Tuesday, March 11th and 12th.
Now that Daylight Saving Time is in effect, the Sun sets at 6:56 PM; night falls at 8:31. Dawn begins at 5:39 AM and ends with the Sun rising at 7:13.
The Moon dominates the southwestern sky. Monday’s Moon blazes in Aries with minus 8th magnitude, appears about 25% illuminated and 50º high. Tuesday’s Moon resides in Taurus, near the fork in the constellation and the bright star Aldebaran. Tuesday’s 6-day-old Moon appears about 34% lit and about 56º in altitude. The Moon sets at 12:01 AM on Tuesday and at 1:06 AM, Wednesday.
Mercury hangs on very low in the West. In Pisces, it appears about 3% lit, about 10 arc-seconds in size and shines with 3rd magnitude. However, it is quite low and may require binoculars to spot amid the twilight. This is the time for last looks for this evening appearance; Mercury sets at 7:32 PM.
Mars remains the only easily observed evening planet. In Aries, it appears about 92% lit, shines with first magnitude and is about 51º high; it sets at 11:48 PM. Uranus shares Aries with Mars, but at the opposite side of the constellation. Uranus shines with 6th magnitude, is about 3 arc-seconds in size and is about 35º high. Uranus sets at 10:16 PM. Note that Mars slowly moves away from Uranus this month.
Once the Moon sets, comet hunters can observe rapidly fading Comet Wirtanen. The comet is now about 101 million kilometers from Earth and growing further daily and reported at 10th magnitude. Still in Ursa Major, it is best observed at 10:22 PM, but the Moon may obstruct the view. The comet is about 75º high between the stars Lambda and Iota. Comet Iwamoto, in Auriga, lies near the star Iota. At 10:00 PM, it is about 47º high and is observed at 8th magnitude. It sets at 1:58 AM. Finder charts from online astronomy websites assist the sky watcher.
At Dawn, the bright planet trio is still visible. Jupiter is first up, at 2:33 AM in Ophiuchus. It shines with minus 2nd magnitude and is about 21º high at Dawn. Jupiter is now high enough for observing features on the giant planet; the Great Red Spot can be telescopically sighted at 3:06 AM on Wednesday.
Saturn, in Sagittarius, is second to rise, at 4:20 AM. It is at minimum brightness – zero magnitude and 11º high at Dawn. It, too, is high enough to appreciate the famous ring system. Note that both Jupiter and Saturn lie to either side of Sagittarius, and that Jupiter is very slowly closing in on Saturn.
Venus continues to hug the eastern horizon, rising at 5:39 AM. Although at Dawn it blazes with minus 4th magnitude and is 75% lit, is lies within a few degrees of the horizon. Binoculars may help find it amid the rapidly brightening sky.
With Red Planet Mars and Uranus sharing the significant constellation of Aries, let us take a look at Aries. The constellation is usually listed as first in the Zodiac. At the time of the Babylonians, Aries housed the Spring Equinox. It also was the constellation that began the Babylonian, Assyrian and Jewish calendars.
Aries, the Ram, is prominent in Greek mythology. Brothers Phrixos and Helle were threatened by their stepmother. Their deceased mother appeared with a golden fleeced ram, and urged her sons to ride its back and escape. They did; however, Helle fell off the ram into the sea. The Hellespont is named after him. Phrixos safely made the crossing and landed in Kolchis, on the Black Sea. He sacrificed the ram to Zeus in thanksgiving and hung its fleece on a tree. This is the Golden Fleece of the Jason and Argonaut saga.