Mercury Meets Jupiter And Moon While Orion Dominates Dark Skies: What You Can See In The Night Sky This Week


Each Monday I pick out the northern hemisphere’s celestial highlights (mid-northern latitudes) for the week ahead, but be sure to check my main feed for more in-depth articles on stargazing, astronomy, eclipses and more. 

What To Watch For In The Night Sky This Week: January 11-17, 2021

With the coming of a New Moon in mid-week our satellite reflects little sunlight, and can only be seen as a slim crescent first just before sunrise, then just after sunset. That makes this week perfect for stargazing in the evenings (don’t miss the glorious constellation of Orion), though there are a few planet sightings to try for if you’re up for a challenge. Not least tiny Mercury, which very few people ever see, making a close approach to Jupiter and Saturn, then to a slim crescent Moon after sunset. 

Monday, January 11, 2021: Mercury and Jupiter in conjunction

Immediately after sunset is the time to go looking for Mercury and Jupiter, which should be detectable in the haze of the southwestern horizon. The two planets will appear to be just 1.4°, with dim Saturn below Jupiter. You’ll need a low view to the southwestern horizon, and preferably any pair of binoculars. 

Wednesday, January 13, 2021: New Moon

At 05:00 Universal Time the Moon slips roughly between the Earth and the Sun and becomes entirely invisible to us. What that means for stargazers is the coming of a string of early evening views of a delicate crescent Moon hanging above the western horizon—followed by dark skies perfect for stargazing. 

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Thursday, January 14, 2021: A crescent Moon meets three planets

Although you will need to have a low view to the southwest as soon as the Sun sets—and probably binoculars, too—the prize for keen eyes is a 3.6%-lit crescent Moon. Look slightly below and to its right and you’ll see Mercury, then Jupiter, then dim Saturn. 

Friday, January 15, 2021: A crescent Moon and ‘Earthshine’

A 8.5%-illuminated crescent Moon will hang a little higher above the southwest after dark. This will be a fine night to observe “Earthshine”—sunlight reflecting off the Earth and on to the lunar surface. It’s only possible to detect with the human eye when the lit portion of the Moon is so slim. 

Saturday, January 16, 2021: A crescent Moon and ‘Earthshine’

Tonight brings another chance, with the Moon tonight 15.2%-illuminated and easy to see after dark for a couple of hours. 

Constellation of the week: Orion, the hunter

A bright and obvious constellation that is at its best this month is Orion. In fact, its very presence in the southern night sky is a sure sign that we’re now in the finest stargazing period of the entire year. A glittering jewel of the winter night sky, its most recognisable sight is, of course, the three stars of Orion’s Belt. However, those three stars aren’t a constellation, but merely an asterism—a simple shape among the stars. The actual constellation includes four corner stars that frame the belt stars; reddish Betelgeuse and blue Bellatrix mark the hunter’s upper body while Rigel and Saiph his bottom half. Tabit marks his shield. 

Object of the week: Orion Nebula

Orion’s Belt also contains one of the finest sights of all, the Orion Nebula or M42. Around 1,270 light years from us, it’s a cloud of gas and dust that’s currently collapsing to form baby stars. It’s an easy target just below Orion’s Belt, though you will have to look just to the side of it to allow your peripheral vision to most easily see its brightness. If you have binoculars, don’t hesitate—M42 looks wonderful with a bit of magnification. 

Times and dates given apply to mid-northern latitudes. For the most accurate location-specific information consult online planetariums like Stellarium and The Sky Live. Check planet-rise/planet-set, sunrise/sunset and moonrise/moonset times for where you are. 

Wishing you clear skies and wide eyes.