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January is a particularly good month for planets, with clear, good views of all five of the naked-eye planets during most of the month. Interestingly enough, the planets will appear in our January sky in the same order as their place in the solar system: the inner planets Venus and Mercury visible right at dusk, Mars above them and becoming visible as it gets fully dark; Jupiter rising in the east as Mars sets in the west in middle evening; and Saturn is up late at night.
PLANETS
January brings a lovely gathering of Venus and Mercury. In late December and early January, look for Venus low in the west around 6:15 p.m. Look in the western sky, where the sun had set about a half hour earlier, for an incredibly bright dot. Venus is so bright that it will pop out easily as it emerges from the twilight at 6:15 p.m. In late December and early January, Venus sets around 7 p.m., so you have only a short time to catch it. By the end of the month Venus will be about 15 degrees above the horizon at dusk and will set a full hour later, at 8 p.m.
Mercury will gather with brilliant Venus for the first few weeks of January. Since Mercury is only about 6 percent as bright as Venus, and hugs the horizon at dusk, use Venus as your guide for finding Mercury.
On Thursday, look for Venus in the west around 6:15 p.m. and try to find Mercury just below it. In early January, Mercury sets by 6:50 p.m., so you have only about 30 minutes to catch it.
Night by night at dusk Mercury will appear to be a little closer to Venus, and on Jan. Mercury will be less than half a degree below Venus (less than the width of the full moon). That night the two planets will emerge from twilight in the west around 6:30 p.m. and will set around 7:30 p.m.
While the two planets will start to separate after Jan. 10, the Mercury-hunting will still be very good Jan. 11-16. During the time Mercury will remain to Venus’ lower right. On those nights, look for the pair emerging around 6:45 p.m. and setting around 7:30 p.m.
From Jan. 17 to 21, Mercury will be noticeably more distant from Venus every night, and noticeably fainter as well. Your last chance to catch the pairing will be around Jan. 21. On that night find Venus, then look immediately to its right for a very, very slender crescent moon. Then look for Mercury, hanging below the moon and Venus like a pendant. You have a very narrow timeslot to see this trio on Jan. 21, from 6:45 to 7:20 p.m., when Mercury sets.
After Jan. 21, Venus will stand alone as a sunset planet.
Much fainter than either Venus or Mercury, Mars soldiers on valiantly, appearing about 20 degrees above the western horizon at dusk (two fists at arm’s length) and setting just before 9 p.m. all month. By the last week of January, Venus will appear close enough to Mars to be a guide: Find Venus’ bright dot first, then look for a faint orange dot about 10 degrees above Venus. A good way to spot Mars in January is to look west on Jan. 22. The slender crescent moon will be just to the right of Mars.
In early January, blazing Jupiter rises in the east. In early January look east at 9 p.m. to catch Jupiter’s bright white light clearing the east horizon. Jupiter will be halfway down the western sky as day breaks. By the end of January, Jupiter rises in the east right at sunset and sets in the west at daybreak. The moon will be close to Jupiter on Jan. 7-8.
Saturn passed behind the sun in November but is already easy to find in the early morning sky. The yellow-white planet rises in the east-southeast at 4:30 a.m. in early January and about two hours earlier than that by the end of the month. Saturn is right in front of the row of four stars that make the claw of Scorpius the Scorpion, and is about 10 degrees above the star Antares in the heart of the Scorpion. Early on the morning of the 16th, look for a slender crescent moon next to Saturn.
QUADRANTID METEOR SHOWER
The Quadrantid meteor shower peaks on the mornings of Jan. 3 and 4. Between 12:01 a.m. and dawn, look east. The peak of the Quadrantids this year exactly overlaps the time of the nearly-full moon, which will really hamper the spotting of the shooting stars.
Earth will be at perihelion, its closest approach to the sun for the year, at 8:36 p.m. Saturday. Like all planets, the earth’s orbit is not a perfect circle but rather an oval. Earth reaches perihelion, its closest approach to the sun, in early January each year.
SOUTHERN CROSS WATCH
The Southern Cross (official name: Crux) returns to Hawaii’s skies every December, where it can be seen just before dawn, and leaves our sky in early July, where it is just barely visible at dusk before the Cross sets. In early January, the Cross rises at 4 a.m. and is due south as day breaks at 6 a.m. By the end of January, Crux rises at 2 a.m., is due south at 4 a.m., and set at dawn.
Seeing the Southern Cross is often a goal of visitors to these islands, and fun for residents as well! Tips:
» The bottom star of the cross, Acrux, is only six degrees above the south horizon when at its highest point as viewed from Oahu. That’s just the width of three fingers at arm’s length. So….
» Find a location that gives you an unbroken south horizon; looking over the sea is best.
» In terms of what to look for: Crux is a small, very compact constellation, shaped like a Roman Cross.
» The bottom star, Acrux, is by far the brightest, at 0.75 magnitude. Fairly bright first-magnitude stars that form the top star of the cross (Gacrux) and the left side of the crossbar (Mimosa). Delta Crucis, the star that forms the right side of the crossbar is a fainter second magnitude star, and finding that can be the trickiest part of cross-spotting.
» It’s often easiest to find the cross when it’s due south (just before dawn in early January, 4 a.m. in late January), when it sits upright on the south horizon and gets as high as it ever gets in our sky.
JANUARY SKY MAP
We have redone our star maps as of January so that they are good for 10 p.m. at the start of each month and 8 p.m. at the end of the month. The map shows all the favorite winter constellations like Orion and the Gemini. Also note the return of the Big Dipper, whose cup is just clearing the horizon. At our more southern latitude, the Dipper is missing in action every fall.
The earlier evening is a good time to find blue-white Canopus, the second-brightest star in the sky. Canopus can’t be seen north of latitude 40 or so, which means viewers from Boston, Seattle, etc., never get to see it.
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