jan 7 TWS feature
Mark took this picture from York Region, Ontario, on October 8, 2014. Flickr
This Week’s Sky: January 6 to 13

The penumbral lunar eclipse, Uranus stands still and the waxing and waning gibbous moon

A waxing and waning gibbous Moon bracketing the full Wolf Moon — and penumbral lunar eclipse for the lucky few in Canada’s north — will grace the skies this week, as Uranus briefly stops its walk in Earth’s skies before resuming its regular eastward orbital motion.

Tuesday, January 7 all night: Gibbous Moon meets Aldebaran

As darkness falls in the Americas on the evening of Tuesday, January 7, the waxing gibbous Moon will be positioned several finger widths to the left (or 2.5 degrees to the celestial north) of the bright orange star Aldebaran, which marks the southern eye of Taurus, the Bull. For the rest of the night, the moon will pull away from that star, and the motion of the sky due to Earth’s diurnal rotation will lift the moon above Aldebaran. On that same date, Observers in Europe and Africa will see the moon pass through the triangular face of Taurus, and much closer to Aldebaran.

Friday, January 10 at 19:21 GMT: Full Wolf Moon and penumbral lunar eclipse

The January full moon, known as the Wolf Moon, Old Moon, and Moon after Yule, always shines in or near the stars of Gemini or Cancer. It rises at sunset and sets at sunrise, and the position of the ecliptic on winter nights causes January moons 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 which will begin when the moon contacts the Earth’s shadow at 17:07:45 GMT. The moon will enter almost completely into the Earth’s northern penumbral shadow, subtly darkening the moon’s southern limb more than its northern limb. However, the effect will be visible only within about 30 minutes of either side of greatest eclipse, which will occur at 19:10:01 GMT. The penumbral eclipse will end at 21:12:24 GMT.

The entire eclipse will be visible from Europe, eastern Africa, and Asia. Parts of northern Canada and the Maritimes and will be treated to only the beginning and final stages of the eclipse, respectively. Those lucky few living in Inuvik or further north will be able to see the full eclipse.

Saturday, January 11 evening: Uranus stands still

On Saturday, January 11, the distant, blue-green planet Uranus will temporarily cease its motion through the distant stars of southwestern Aries — completing a westward retrograde loop that began in early August. After tonight, the planet will resume its regular eastward orbital motion. Magnitude +5.77 Uranus can be seen in binoculars and backyard telescopes, and with unaided eyes under dark skies. Use the nearby, naked-eye stars Omicron (o) Piscium and Eta (η) Piscium to guide you.

Saturday, January 11 evening: Bright Moon buzzes the Beehive

When the bright, waning gibbous moon rises in the northeastern evening sky on Saturday, January 11, it will be sitting very close to the left side of the large open star cluster known as the Beehive. The brightest deep sky object in Cancer, the cluster is also called Praesepe and Messier 44 (or M44). The moon and the cluster will both fit within the field of view of binoculars (orange circle), although the bright moonlight will obscure the cluster’s dimmer stars. For best results, place the moon just outside of the left edge of your binoculars’ field of view and look for the cluster’s many stars.

Chris Vaughan is a science writer, geophysicist, astronomer, planetary scientist and an “outreach RASCal.” He writes Astronomy Skylights, and you can follow him on Twitter at @astrogeoguy. He can also bring his Digital Starlab portable inflatable planetarium to your school or other daytime or evening event. Contact him through AstroGeo.ca to tour the universe together.