Overhead in the heavens, the moon hits the celestial bull's-eye this week, while sky-watchers hunt down a distant crab.
Moon meets green giant. After darkness falls on Monday, December 1, look for the waxing gibbous moon high in the southern sky to come close to the planet Uranus. (See "Newfound Mega-Storms on Uranus Pose Planetary Puzzle.")
The ice giant will appear less than one degree—a distance of a bit less than two full moons apart—below and to the right of luna. This close conjunction will be best seen through a small telescope because the moon's glare will interfere with views of the tiny (5th magnitude) green disk.
As an observing challenge for suburbanites, see if you can track down Uranus using just binoculars.
Geminids ramp up. The famed Geminid meteor shower kicks off on Thursday, December 4, but the shower will not peak until December 13. Expect just a trickle this week, with only 5 to 10 meteors per hour visible to the naked eye.
Each Geminid shooting star can be traced back to its namesake constellation, Gemini, the Twins, which currently rises in the northeast late at night.
Moon and bull's-eye. Look for the nearly full moon next to the red eye of Taurus, the Bull, late at night on Friday, December 5.
The great red giant Aldebaran will appear only 1.5 degrees from the moon, making for a spectacular conjunction.
Aldebaran, 66 light-years distant, marks the bull's-eye in this storied constellation. The rest of the bull's face is made of the V-shaped Hyades cluster of stars. With the moon's glare in the way, the cluster is best seen with binoculars.
However, we can easily witness the moon's motion across our sky as Earth's only natural satellite glides by the Hyades cluster in just a matter of a few hours.
Jovian moon eclipse. Beginning at 2 a.m. EST on Saturday, December 6, look for Jupiter's moon Callisto to cover its neighboring moon Europa. The entire occultation event lasts 56 minutes and is visible through even the smallest backyard telescope.
You may notice that the combined light of the two moons during this time becomes noticeably fainter—dropping by some 20 percent. That is because Callisto's heavily cratered surface is darker than the surface of bright, ice-covered Europa.
Crab Nebula. On the evening of Saturday, December 6, backyard telescope users can hunt down the sky's most famous—and arguably best—example of a supernova remnant, thanks to the moon pointing the way.
Look for the faint Messier 1, otherwise known as the Crab Nebula, approximately 4 degrees above the moon. That is slightly less than the width of your fist held at arm's length.
The Crab Nebula shines faintly at magnitude 9 and sits about 7,000 light-years away from Earth. It was actually first seen in the sky by Chinese astronomers when it exploded in the year A.D. 1054.