January 2008
Skywatchers’ Guide for January 2008
PLANETS
Mars continues to impress as its excellent apparition concludes this month. To celebrate this excellent apparition of Mars, Flandrau continues its special events on Fridays and Saturdays with two more on January 4 and 5. Special telescope viewing (weather permitting) with the Tucson Amateur Astronomy Association on the UA mall will be held from 6:30 until 10 p.m. on January 4/5. At 8:00 p.m. both nights, come see special live planetarium presentations on Mars by University of Arizona researchers associated with the associated with The Phoenix Mars Mission, set to land on the north pole of Mars in May of 2008. Each presentation will involve a special area of research associated with The Phoenix Mars Mission, led by The University of Arizona, the first university to lead a mission to Mars.
On December 18, 2007, Mars reached 54.8 million miles distant, the closest it will be to the Earth until the year 2016. This was six days before its opposition date (Dec. 24), when Mars is opposite from the Sun in the sky. Mars is still at its best in early January when over 15 arc seconds in apparent size, but shrinks to 12 arc seconds in apparent size by the end of the month. This means this is probably the last month to see surface features well with the eye in amateur telescopes, though amateur astronomers with imaging systems can still do well with imaging the Red Planet. During the month Mars fades from a very bright magnitude -1.6 (brighter than Sirius, the brightest star in our night sky) to magnitude -0.6. Mars conveniently reaches above 40 degrees in altitude in early January by 7:45 p.m. (40 degrees in altitude is high enough in the sky for typical sharp telescopic viewing; the higher the altitude, the less air is being looked through). For this reason (and because Mars shrinks only slightly in early January), observers can take advantage of more convenient evening telescopic during January when Mars is higher up, earlier at night.
Like any planet, Mars should be viewed in a telescope when it is high in the sky. Early in January Mars is visible all night long, as it rises just before sunset and is overhead around midnight. Best views of any planet should be when it is highest in the sky, but viewing is dependent on atmospheric stability and conditions, and of course, the quality and size of the telescope used. Large, high quality amateur telescopes in good “seeing” (stable atmospheric conditions) will best reveal any features on the Martian disk. Mars is highest in the sky this month at around 11:30 a.m. in early January, at 10:30 p.m. in middle January and by 9:15 p.m. in late January (by which time it will be difficult to see surface contrast features in amateur telescopes). When highest in the sky this year the Red Planet “transits” the meridian (the north/south line in the sky) at 84 degrees in altitude for southern Arizona. This is much higher than Mars reached in August during its record close apparition that year and higher than in 2005. Even though Mars will be significantly smaller this year than in 2003, its placement overhead may offer sharper telescopic viewing, especially for desert Southwest observers. Observers should also note that the southern and northern polar caps may more easily seen than in 2003 or 2005, as they face equally towards Earth.
Mars can be first seen well above the east-northeastern horizon by around 6:15-6:30 p.m. in the early January twilight. Mars, moving in retrograde or reverse motion, creeps out of the constellation boundary of Gemini, the Twins and into Taurus the Bull. Mars stops retrograde motion on January 30. Finally, look for the waxing gibbous Moon near Mars in our sky this month on the night of January 19/20; The two are high in the east on the evening of Saturday, January 19.
Currently a Mars hoax e-mail might still be found making its way around the Internet, stating that Mars will be closest to the Earth in 60,000 years. Please go to our news story for more information.
Saturn is still near (eight degrees from) the bright star Regulus in the constellation Leo the Lion. Saturn appears as a closer to first magnitude star-like object (at magnitude 0.8), and is dimmer this year because its rings are more edge-on. Saturn continues to gain altitude while Venus will slowly sink out of view in early 2008. Saturn rises earlier each night and is very high overhead at dawn by the start of the month. On January 1 Saturn rises just after 10 p.m but by January 31 Saturn rises at around 7:50 p.m. above the eastern horizon. Saturn’s opposition date will be on February 24, when it is opposite from the Sun in the sky. This is four days before Saturn will be wonderfully (apparently) close to the totally eclipsed Moon on the evening of Wednesday February 20. Stay tuned on this Web page for more on the last total eclipse until December 2010. Also look for the waning gibbous Moon rising near Saturn (about 2 degrees north or slightly above Saturn) at around 9 – 9:15 p.m. on Thursday January 24. The Moon will be visible near Saturn all that night, and is also not far from Saturn in our sky on the previous night (Jan. 23/24).
The brilliant planet Venus remains our ‘morning star’ this month in the east but loses altitude in our morning twilight sky. In the process Venus groups with Jupiter by the end of the month (see below) in a spectacular conjunction. Even so Venus rises around 3 hours before the Sun in early January, but only 2 hours before sunrise by the end of the month. In early January Venus is around 20 degrees in altitude above the eastern horizon about one hour before sunrise (around 6:25 a.m. for southern Arizona). As Venus continues to recede from Earth it continues to shrink in apparent size in a telescope, and now appears from Earth in a gibbous phase. To the unaided eye Venus appears as an intensely bright white star that does not twinkle and all month long is found above the eastern horizon, 45 minutes to one hour before sunrise. The waning crescent Moon is grouped near Venus on Friday morning, January 4, during the peak night of the Quadrantid meteor shower (see below).
Bright Jupiter emerges in the January morning twilight, and has a spectacular grouping with Venus by the end of the month, and into early February. Jupiter gains altitude each morning in the southeastern sky. From the southernmost United States the giant planet might first be noticed with the naked eye along with a razor thin crescent Moon just two degrees above the east-southeastern horizon on the morning of January 6th, about 35 minutes before sunrise (sunrise for southern Arizona is then at 7:25 a.m.). Jupiter becomes much easier mid-month and by January 21 is about 10 degrees in altitude, 35 minutes before sunrise. By that date Jupiter is already obviously loosely grouped with Venus in the morning sky. The two planets creep closer in the sky by almost one degree each morning that week. By January 31 the two worlds are a little more than one degree apart in our dawn sky making for a spectacular conjunction that will continue for several mornings. The two planets are closest on February 1st, when only 0.6 degrees apart in our sky. This is the closest such possible grouping (that’s easily visible) of the two brightest planets until the year 2014 (Jupiter is usually the 2nd brightest planet in the sky but Mars can outshine it about every 15 years).
Mercury has a fine evening apparition and is visible to the naked eye in the northern hemisphere during the latter half of January near the southwestern horizon. Mercury is best visible from January 15-27 around 45 minutes to one hour after sunset when it will be between 5 and 8 degrees above the southwestern horizon. The razor thin waxing crescent Moon might be seen in clear skies above and nearest Mercury in our evening twilight sky on Wednesday, January 9. However around that date Mercury is only 2 degrees above the horizon as seen from southern Arizona, 45 minutes after sunset at 6:20 p.m., making for a difficult observation! As always binoculars are helpful in spotting Mercury, especially 30 minutes after sunset. Also, the first spacecraft to orbit Mercury, THE MESSENGER spacecraft has arrived in its first flyby of Mercury. The spacecraft is set to orbit the elusive world in 2011. Only 45 percent of Mercury up to this time has been imaged by space probes. To see the latest images, and find details about the MESSENGER spacecraft and the Mission Operations Center click here.
Visitors to Flandrau’s 16-inch telescope should note that only Mars is currently visible in the telescope during normal operating hours. Other celestial objects will be shown, weather permitting.. Flandrau’s main exhibit hall and planetarium are closed on Wednesdays but the telescope remains open, weather permitting Wednesday through Saturday nights (excluding select holidays). The telescope normally closes at 10 p.m.
Finally, remember that in spotting planets there is a general rule: ’stars twinkle, planets don’t’. This is because stars are point sources of light; therefore starlight is easily disturbed and shifted by air currents in the Earth’s atmosphere. However when looking at Mercury right now, note that it may appear to twinkle somewhat; however, this twinkling is of a slower nature than the bright stars.
Comet Holmes continues to enlarge, fade
Previously small, faint Comet Holmes (designation 17P) is still visible in binoculars. The comet surprised astronomy observers around the globe by outbursting and suddenly becoming bright enough (at a visual magnitude rating of 2.5) to see with the naked eye back on October 25, 2007. Click here for our news story to learn more.
2008 IS A GOOD YEAR FOR THE QUADRANTID METEOR SHOWER!
 The northern sky around the Quadrantid meteor shower radiant is shown around 3 a.m. on January 4. |
Stargazers who brave the cold may get a good view this year to see the little known Quadrantid Meteors in the pre-dawn hours of Friday morning, January 4. The moon, grouped with Venus is a thin waning crescent 4 days before new, making 2008 a close to ideal year for this early morning meteor shower. Although not as good as the Perseids in August, or the Geminids in January, the Quadrantids can still put on a respectable show. Meteor watchers, warmly dressed and with ample supplies of hot chocolate, should seek out a dark sky several miles away from city lights and scan the sky starting at midnight from high in the south and east to overhead. To see the highest number of meteors (about 20-45 per hour), you’ll need to look after 2 a.m., and until dawn in dark skies. Early rises can catch the shower for an hour before dawn starting at around 5:15 a.m. Quadrantid meteors appear to originate from an area of the sky below the Big Dipper: To see the most meteors look anywhere around the Big Dipper and overhead after 2 a.m., and anytime afterwards until dawn.
JANUARY EVENING STARS
 This sky chart shows the eastern sky at 9 p.m. in early January, at 8 p.m. in mid-January and at 7 p.m. in late January. |
In early January look in the east for the bright stars of winter to rise around 8 p.m. Orange Betelgeuse, the shoulder of Orion the Hunter, shines left of Orion’s 3 glittering belt stars. The Gemini Twins, the bright stars Castor and the slightly brighter Pollux twinkle left of Orion. An hour later, by 9 p.m., the bright star Procyon (whose name means “Before the Dog”) is newly risen in the east. From Tucson’s latitude, the Dog, – that is the “Dog Star” Sirius– the brightest star in all the heavens, rises almost at the same time as Procyon, so Procyon’s name isn’t so true this far south. Watch for brilliant Sirius to flicker different colors dramatically when low in the sky, a wonderful sight in binoculars. The flickering is due to earth’s atmosphere.
MOON PHASES
The January new Moon is on Tuesday Jan. 8, and first quarter is on Tuesday Jan. 15th. The January Full Wolf Moon (as named by native Americans) rises on Monday January 21 and sets on the morning of Tuesday January 22. The January 2008 last quarter Moon will occur on Wednesday morning January 30th.
Note: Additional information can be accessed by phone at Flandrau Science Center’s Astronomy Newsline at (520) 621-4310 or as a menu option at 621-S-T-A-R.
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