This is Dudley Observatory’s Skywatch Line for Friday, January 10, through Sunday, January 12, written by Sam Salem.
On Friday, Sun rises at 7:26am and sets at 4:41pm. Full Moon occurs on Friday at 2:21pm; the full Moon rises at 4:38pm and sets at 7:20am. Full Moon rises almost at sunset and sets at sunrise. The position of the ecliptic on winter nights causes January Moon to culminate very high in the night sky. This full Moon will occur while the Moon is partially on the ecliptic, producing a penumbral lunar eclipse. The entire eclipse will be visible from Europe, eastern Africa, and Asia. Parts of northern Canada and the Maritimes will only see the beginning and final stages of the eclipse.
On Saturday evening, bright Moon rises in the northeastern evening sky. It will be sitting very close to the left side of the large open star cluster Beehive. The brightest deep sky cluster in constellation Cancer is also called Messier 44. The Moon and the cluster will both fit within the field of view of binoculars. The bright moonlight will obscure the cluster’s dimmer stars. Place the Moon just outside of the left edge of your binoculars’ field of view and look for the cluster’s stars.
On Saturday, the blue-green planet Uranus will temporarily cease its motion through the distant stars of southwestern constellation Aries the Ram. This completes a westward retrograde loop that began in early August. The planet will then resume its regular eastward orbital motion. The outer planet appears highest in the south once darkness falls, when it stands two-thirds of the way to the zenith. The magnitude 5.8 planet lies in southwestern Aries the Ram, near that constellation’s border with Pisces the Fish and Cetus the Whale. The closest guide star is magnitude 4.4 Xi1 (ξ1) Ceti, which lies 4 degrees to the southeast. A telescope reveals Uranus’ disk, which spans 3.6″ and shows a distinct blue-green hue.
Mercury reaches superior conjunction at 10am on Friday. This means the innermost planet lies on the opposite side of the Sun from Earth and remains hidden in our star’s glare. It will return to view in the evening sky late this month.
Mars grows more prominent before dawn with each passing week. The Red Planet now rises just after 4am and climbs 20 degrees above the southeastern horizon an hour before sunrise. Mars glows at magnitude 1.5 against the backdrop of constellation Scorpius the Scorpion, some 6 degrees north-northwest of its ancient rival, the 1st-magnitude star Antares in constellation Scorpius.