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The brightest planets in January's night sky: How to see them (and when)

The new year begins with four of the five naked-eye planets strung out along a crooked diagonal line measuring nearly 40 degrees above the south-southwest horizon an hour after sunset. 

Your clenched fist held at arm’s length measures 10 degrees, so these four planets — in this order: Venus, Mercury, Saturn and Jupiter — will span an area measuring roughly “four fists” on the first evening of 2022. 

In the evenings that follow, the two inner planets, first Venus and then Mercury will vanish, dropping back toward the sun. Saturn disappears after the middle of the month and by the end of January the only evening planet left to be seen will be Jupiter.

(Image credit: NASA/JPL-Caltech)

So far as the early morning is concerned, Mars is the lone planet in evidence, very low in the southeast before sunrise, near to its “rival,” the ruddy first magnitude star, Antares. But by midmonth, Venus will have reappeared, taking up residence in the dawn sky until the end of August. And by month’s end, Mercury will also be visible not far from Venus, if not with the unaided eye than certainly with binoculars for anyone carefully scanning the sky to the lower left of Venus.

In our schedule, as previously mentioned, remember that when measuring the angular separation between two celestial objects, your clenched fist held at arm’s length measures roughly 10 degrees. Here, we present a schedule below which provides some of the best planet viewing times and directs you as to where to look to see them.

Mercury

On Friday morning, Jan. 7 in the Americas, Mercury (orbit shown in red) will reach its widest separation of 19 degrees east of the sun, and maximum visibility for the current apparition.  (Image credit: Starry Night)

Beginning on Jan. 3, and for each evening thereafter running through Jan. 12, viewers at mid-northern latitudes who look 30 minutes after sunset will see this speedy little planet about 9 degrees above the southwestern horizon. Should you locate it on the evening of Jan. 3, use binoculars and scan 5 degrees below it to catch sight of an exceedingly thin waxing crescent moon, just 31 hours past new and 2% illuminated. 

On Jan. 7, Mercury achieves its greatest elongation of 19 degrees from the sun; a moderately favorable apparition. It is more than half lit then (58% to be exact), so it shines at magnitude -0.6, brighter than usual at maximum elongation. But during the second week of January, Mercury starts to fade rapidly, from magnitude +0.1 on the 11th to +1.8 six nights later. Mercury will be passing near Saturn on Jan. 13 (see “Saturn” below). 

On Jan. 23, Mercury goes through inferior conjunction (passing between Earth and sun), but just over a week later it emerges back into view by the end of January, now low in the dawn. This morning it shines at magnitude +1.4 and hangs about 6 degrees above the southeastern horizon and 15 degrees to the lower left of Venus, a half-hour before sunrise (for mid-northern viewers). That should be just high enough for it to be visible with binoculars if the air is very clear. This is a rare opportunity to spot the notoriously elusive innermost planet both at dusk and at dawn during the same calendar month. 

Venus

To kick off 2022, the inner planets Mercury and Venus will shine together low in the southwestern sky after sunset on Saturday, Jan. 1. (Image credit: Starry Night)

Venus makes a dramatic exit from the evening sky during the opening days of 2022. It is low but prominent in the southwest after sunset on New Year’s Day, blazing at magnitude -4.4 and still sets more than an hour after the sun. Telescopes — or even steadily supported binoculars — show that its globe is just 2% lit, and this slender crescent measures an amazingly large 61 arc seconds (3.3% of the apparent diameter of the moon) from tip to tip. Each day after, Venus appears noticeably lower, and its crescent grows even thinner; check it with any telescope or steady binoculars — or maybe even your naked eyes. 

By Jan. 6th, Venus appears only about 5 degrees above the horizon at sunset for observers at mid-northern latitudes. What’s the last day you can spot it after sunset? On Jan. 8, Venus goes through inferior conjunction and transitions into the morning sky. A week later it rises just over an hour before the sun, and by month’s end the “morning star” is about 14 degrees high 45 minutes before sunrise. Its light has then brightened to a splendid magnitude -4.8 and its crescent has widened to 15%.

Earth

On Tuesday, Jan. 4, Earth will reach perihelion, its minimum distance from the sun for the year. (Image credit: Starry Night)

Earth comes to perihelion, closest to the sun in space, at 1:55 a.m. EST. It is then 91,406,842 miles (147,105,053 kilometers) from the sun.

Mars

On Saturday, Jan. 29, the pretty, slender crescent of the old moon and the bright reddish dot of Mars will rise together in the southeastern sky shortly after 5 a.m. local time — making a lovely photo opportunity when composed with some interesting scenery. (Image credit: Starry Night)

Mars is still rather difficult to see in the early morning sky. This orange-yellow-hued world rises about a half-hour before the break of dawn all through January and glows only at a modest magnitude of +1.5 while remaining rather low to the southeast horizon. 

It starts January positioned 5.5 degrees to the left of the star Antares. The so-called “rival of Mars” lives up to its name, as it appears noticeably redder and a half magnitude brighter than its planetary neighbor. Mars gradually pulls away from Antares during the rest of the month. On Jan. 29 at about an hour before sunrise, low to the southeast horizon, you’ll see a slender crescent moon and about 3.5 degrees to its upper left, glowing feebly (compared to nearby Venus) will be Mars. 

Jupiter

(Image credit: Starry Night)

Jupiter blazes in eastern Aquarius and shines fairly high in the southwest as the sky grows dark, and on the evening of Jan. 5, the ever-widening waxing crescent moon passes about 6 degrees below it. But by month’s end Jupiter is much lower and sets about a half-hour after the end of twilight (for observers at mid-northern latitudes). 

Saturn

The moon will make its monthly trip past the bright gas giant planets starting on Tuesday evening, Jan. 4. Once the sky begins to darken after sunset, the creamy dot of Saturn will appear shining several finger-widths to the upper right (or 5 degrees to the celestial southeast) of the slim crescent moon, close enough for them to share the view in binoculars (green circle). (Image credit: Starry Night)

Saturn appears as a moderately bright yellowish-white “star” shining well to lower right of a much brighter Jupiter early in the month. The ringed planet sets about 2.5 hours after sunset on New Year’s Day. On Jan. 4, a 6% illuminated, waxing crescent moon will lie about 5 degrees to the left and slightly below Saturn. On Jan. 13, Saturn and Mercury engage in a “quasi conjunction.” 

According to celestial calculator Jean Meeus, this is when two bright planets approach to within 5 degrees of each other without a conjunction in right ascension. In this case, Mercury passes 3.4 degrees to the lower right of a somewhat dimmer Saturn. Mercury rapidly fades away several evenings later, while Saturn drops into the sunset fires and disappears during the third week of January. 

Joe Rao serves as an instructor and guest lecturer at New York’s Hayden Planetarium. He writes about astronomy for Natural History magazine, the Farmers’ Almanac and other publications. Follow us on Twitter @Spacedotcom and on Facebook. 

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