5 Sky Events This Week: Ice Giant, Lunar Wonder, Ex-Comet Shower

The Straight Wall, or Rupes Recta, cuts across the face of the moon and is visible in small telescopes this week. Photograph courtesy JAXA/SELENE
The Straight Wall, or Rupes Recta, cuts across the face of the moon and is visible in small telescopes this week. Photograph courtesy JAXA/SELENE

Sky-watchers get a chance to see a giant lunar wall, hunt down a distant world, and the moon makes for a convenient guidepost in hunting down a distant planet.

Green Giant. Late night on Tuesday, January 7, the seventh planet from the Sun, Uranus, will pass near the moon. The green giant will appear about 9 degrees southwest from the moon—just shy of the width of your first at arm’s length. This week after darkness falls the near full moon acts as a convenient guidepost for finding Uranus.

The green-colored ice giant has four times the width of Earth, but since it lies nearly 1.9 billion miles (3.1 billion kilometers) away from Earth, it’s barely visible to the naked eye—and only in very dark, pristine skies.

With the glare from the nearby moon, binoculars will be your best bet in spotting Uranus. Just look for a tiny greenish-blue disk in the field of view. By the way, the absorption of red light by methane in the atmosphere is what gives Uranus its cool cyan coloring.

Lunar Straight Wall. The first quarter moon coming into view on Tuesday evening, January 7, is the best time of the month to view in small telescopes a striking lunar feature called the lunar wall. A fault line that stretches 75 miles (120 kilometers) in length and is more than 1,300 feet (400 meters) deep casts a distinct straight and dark line through your eyepiece. (Get a finder’s chart and read more about lunar wonders.)

Possible ISON Shower.  Starting on the night of Friday, January 10, look for a possible meteor shower left behind by ex-comet ISON.  While comet ISON may be history—breaking up as it swung by the sun back on November 28th last year—experts believe there is a small chance it may have left behind a trail of debris that could become visible to sky-watchers as shooting stars. According orbital models, Earth may slam into a meteor stream associated with comet ISON this week and that this one-off shower could last for a few nights.

Moon and Seven Sisters.  After nightfall on Friday, January 10, the waxing gibbous moon will pair up with the most famous star cluster in the entire sky, the Pleiades or Seven Sisters.

With up to seven stars visible to the naked eye in suburban skies, and scores more through binoculars, the Pleiades is 400 light years away and is one of the closest clusters to Earth. Try using binoculars to cut through the lunar glare to see details in this cosmic jewel box.

Moon and the Red Eye of Taurus. As dusk settles in on Saturday, January 11, look for the silvery moon to pose near the bright orange star Aldebaran in the southeast sky.

Earth’s natural satellite will appear only 3 degrees from the 68 light-year distant red giant—equal to the width of your three middle fingers at arm’s length.


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Meet the Author
Andrew Fazekas, aka The Night Sky Guy, is a science writer, broadcaster, and lecturer who loves to share his passion for the wonders of the universe through all media. He is a regular contributor to National Geographic News and is the national cosmic correspondent for Canada’s Weather Network TV channel, space columnist for CBC Radio network, and a consultant for the Canadian Space Agency. As a member of the Royal Astronomical Society of Canada, Andrew has been observing the heavens from Montreal for over a quarter century and has never met a clear night sky he didn’t like.