Categorized | Sci-Tech

Skywatch: Planets on parade

(Sky Watch is a regular column written by Mike Shanahan, director of education and exhibits at the Bishop Museum in Honolulu. He can be reached at

January 2012 is a great month for planet-watching.


You have probably noticed Venus already in December as the brilliant light in the west above the glow of the setting sun. Shining at minus 4 magnitude, Venus is much brighter than Jupiter, the only other dot of light that even begins to approach her brilliance. At the start of the month, Venus is about one-third of the way up in the western sky at dusk at sunset and will set at 8:30 p.m.

Every night Venus will be a little bit higher when the sun goes down. By the end of January Venus will be 40 degrees above the western horizon, which is nearly halfway up in the west. At the end of the month, Venus will not set till 9:15 p.m. Look for a slender crescent moon next to Venus on Jan. 25 and Jan. 26.


Jupiter is the other bright dot in the January night sky, and has in fact been our evening companion for months. At minus 2.5 magnitude Jupiter is four times dimmer than Venus, but twice as bright as any other dot of light in the sky. Look for Jupiter near the top of the sky around dusk at the start of January.

In early January Jupiter will work its way down the western sky in the course of the evening and will set in the west around 1 a.m.

By the end of January, Jupiter will be about 2/3 of the way up in the west at dusk and will set just after midnight. By the end of the month you’ll be able to take in these two brilliant lights of Jupiter and Venus with one look toward the west. Jupiter will be two-thirds of the way up in the west at sunset, and brighter Venus will blaze away below Jupiter.

Look for the waxing gibbous moon next to Jupiter on Jan. 2. The moon will return at the end of the month to appear close to Jupiter on Jan. 29, now as a waxing crescent moon.


The planet Mars has been a fairly unspectacular sight in our early morning skies recently. That changes in January 2012.

Mars will double in brightness in January, moving from magnitude 0.2 at the start of the month to minus 0.5 at the end of January.

Look for Mars rising in the east at 11:30 p.m. at the start of January. It has a pale orange hue. Early in the month, Mars will rising up in the eastern sky in the early hours of the morning and will be high overhead at dawn.

By the end of January, Mars rises at 9:30 p.m., blazes at minus 0.5 magnitude, and will be about high in the western sky as day breaks.

Look for the waning gibbous moon next to Mars on the nights of Jan. 12-13 and Jan. 13-14.


Saturn is in the morning sky. The slightly yellowish planet rises at 2 a.m. at the start of January and is about halfway up in the east at dawn. By the end, the planet rises at midnight and is high in the south at dawn. Saturn shines around 0.6 magnitude.

Throughout the month, Saturn is next to the bright star Spica. Saturn is slightly brighter and slightly yellower than Spica, which shines at 0.96 and is bluish white. The two dots are about 7 degrees apart, or roughly the width of three fingers held at arm’s length. Saturn is below Spica as the two dots of light rise in the east.

By 5 a.m. Saturn and Spica stand side by side, high in the southern sky, with Saturn on the left. Look for the last quarter moon just below Saturn and Spica early on the morning of Jan. 16.


Mercury is visible for the first week of January in the morning sky. The planet rises in the East Southeast at 5:45 a.m. on Jan. 1 and is about 10 degrees above the horizon (one palm at arm’s length) by daybreak.

By Jan. 10 it comes up at 6:10 a.m. and is washed out by the rising sun 20 minutes later. During this brief appearance, the planet remains consistently bright at minus 0.36 magnitude.

Quadrantid Meteor Shower

The first meteor shower of the year occurs on the night of Jan. 3-4. In other words, stay up late Jan. 3, and look for meteors in the early hours of Jan. 4.

The waxing gibbous moon sets around 3 a.m. Jan. 4, so the viewing will be better from that time till dawn.

This shower can produce 120 meteors per hour. Meteor showers are always named for the constellation that the meteors appear to come from.

In this case, “Quadrantids” refer to a part of the constellation of Bootes the Herdsman that used to be called Quadrans Muralis, or “mural quadrant” (an astronomical instrument). Bootes rises about 2 a.m. Jan. 4.

The January Sky Map

The map for January 2011 is good for 11 a.m. at the start of January, 10 p.m. in the middle of the month, and 9 p.m. at the end of January. As always, hold this map over your head or the four directions will never line up!

Of special note, the familiar constellations of winter are clustered high overhead.

Look for Orion the Hunter in the middle of the map. It has a familiar hour-glass shape, distinctive belt of three stars, and brilliant stars Rigel and Betelgeuse. Orion is surrounded by a who’s who of bright winter stars and constellations.

This includes Canis Major, the Big Dog. Sirius, the bright star in Canis Major, is called the Dog Star and is the brightest star in the sky. (Jupiter and Venus are brighter, but they are of course planets.)

Above Canis Major is the bright blue star Procyon, in Canis Minor, and then the Gemini, with its twin bright stars Castor and Pollux. Continuing clockwise, look for Auriga the Charioteer (a constellation called Hokulei in Hawaiian, or “lei of stars”) with its bright star Capella.

Completing the gathering, continue on to Taurus the Bull with bright Aldebaran for its eye.

Other winter constellations in the low eastern sky include Auriga the Charioteer, with its brilliant yellow star Capella; the Gemini, marked by the twin bright stars Castor and Pollux; and Taurus the Bull, with the reddish Aldebaran marking its eye.

In the west, you can still catch the Great Square of Pegasus.

In the north, we see the cup of the Big Dipper rising. The two stars in the cup that don’t have the handle attached are the pointer stars, and they point you nicely to the North Star.

In the south, Canopus, the second-brightest star in the sky, shines clearly in the Hawaiian sky. This is a very good example of a star that is not visible from more northern locations on earth.

If you are anywhere north of 34 degrees north latitude (roughly the latitude of Los Angeles), you will never see this star rise.

Stars that aren’t on the map:

The Southern Cross December rises by 3:40 a.m. at the start of January, 2:40 p.m. in the middle of the month, and 1:40 a.m. at the end. Look very low in the south for the Southern Cross; you need to make sure there are no buildings or trees blocking your south horizon. Its bottom star, Acrux, only gets about six degrees above the horizon at its highest point, or the width of two fingers at arms length.

Moon phases
First Quarter: Dec. 31, Jan. 30
Full Moon: Jan. 8
Third Quarter: Jan. 15
New Moon: Jan. 22

All dates are Hawaii Standard time.

— Find out more:
Bishop Museum Planetarium:

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