Winter begins in the northern hemisphere this afternoon, as the Sun appears farthest south in our sky for the year. This point is known as the winter solstice, and it brings the shortest day of the year.
Weekly Stargazing Tips
Unless otherwise specified, viewing times are local time regardless of time zone, and are good for the entire Lower 48 states (and, generally, for Alaska and Hawaii). Check out last week's tips if you missed a night.
Rigel, the brightest star of Orion, the hunter, is low in the east-southeast in early evening, to the right of Orion’s Belt. It is more than 20 times as massive as the Sun, dozens of times larger, and roughly 100,000 times brighter.
The stars offer a holiday decoration this evening: the Northern Cross, which is also known as Cygnus, the swan. Its brightest stars form the shape of a crucifix, which stands almost straight up from the northwestern horizon at nightfall.
Moon and Mars
Mars and the Moon stage a pretty encounter this evening. Mars looks like an orange star close to the left of the Moon. They are low in the southwest at nightfall and set a couple of hours later.
Moon, Mars, and Venus
Like bulbs on a strand of Christmas lights, three worlds line up in the southwest early this evening. The most prominent is the Moon. Mars stands below and to the right of the Moon, with dazzling Venus far to the lower right of Mars, just above the horizon.
The star that gives the "dog days" their name is visible for most of the night during the winter months. The star is Sirius, in Canis Major, the big dog. It’s the brightest star in the entire night sky. It rises in the southeast around 8 or 9 p.m.
Moon and Fomalhaut
The Moon stands well up in the south as darkness falls this evening, with the bright star Fomalhaut far below it. Fomalhaut represents the mouth of Piscis Austrinus, the southern fish.