Current
Astronomy "Headlines"
First Quarter December 05
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Full Moon
December 12
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Last Quarter
December 19 |
New Moon
December 27
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Listed
below are notable astronomical events coming up for the month of
December 2008:
Naked-Eye
Planets
Mars
Mars will essentially be out of sight, or viewing anyway, for the entire month of December. Mars reaches solar conjunction on the 5 th, and thereafter becomes a morning object. However, Mars will still be so deep in the Sun’s dawn glare that one still not be able to observe it with the naked eye at all for the remainder of the month. Chances to observe will improve somewhat by next month!
Mercury
Mercury begins December deep in the glare of sunset and pretty much remains there, although slowly climbing out, for at least the first half of the month. By about the last week of the month, Mercury is at last high enough to see after the Sun’s light has faded from the evening sky. On the evening of the 28 th, Mercury actually is joined by the young crescent Moon while close to an ever-sinking Jupiter in the evening! On New Year’s Eve, Mercury comes into a tight conjunction with Jupiter (only about 1 degree!), visible only over a very flat WSW horizon. Mercury shines at a bright (though not as brilliant as Jupiter) magnitude -0.7 at this time.
Jupiter
Jupiter begins December in conjunction with Venus and the crescent Moon on the 1 st of the month. Thereafter, Jupiter sinks nightly into the glare of sunset, thereby making it viewable only with a very low WSW horizon. On the evening of the 28 th the very young Moon comes to its closest to Jupiter for the month while it is even closer to the planet Mercury, and Jupiter ends the month only about 1 degree from Mercury, which catches up to it by then! If you have the flat horizon, you might still be able to observe the giant Jupiter in a telescope, revealing cloud bands and the 4 Galilean moons. Even a pair of binoculars, though, will reveal at least some of these 4 moons, provided you can hold your binoculars steadily enough! At this time, Jupiter shines at a brilliant magnitude -1.9, and sports a large, though shrinking, 32.60 arc-second equatorial diameter, and a 30.49 arc-second polar diameter.
Venus
Venus will begin the month of December setting in conjunction with Jupiter and the Mon on the 1 st of the month. Venus this month continues to set later and later every night, and therefore sets slightly later every night than it did on the previous one. Venus crosses into Capricornus after about the first week of the month, then proceeds to cross the constellation all month long. Venus finally crosses into Aquarius by about the end of the month, ending up in conjunction with the crescent Moon on New Year’s Eve at the same time that Jupiter and Mercury are in such close conjunction! Venus shines at about magnitude -4.3 by this time.
Saturn
In early December, Saturn rises at about 12:45 a.m. in the southeastern part of the constellation Leo about 2 degrees east of the 4 th – magnitude Sigma Leonis. The Last-Quarter Moon bypasses the Ringed Planet on the mornings of the 18 th and 19 th, and by month’s end, Saturn rises at about 10:50 a.m. – finally an evening object again! If you have even a modest telescope, you might be able to observe Saturn and its ring system in the eyepiece beginning with modest power (at least 30x-35x). In addition, Saturn’s largest moon, Titan, can nearly always be seen relatively close to the planet. With good seeing conditions, up to nearly a half-dozen other Saturnian satellites are within reach of most moderately-sized backyard telescopes! At the end of the month the rings’ major axis is 41.7” and minor axis is 0.6”. At this time, Saturn will shine at magnitude 0.9 and show an equatorial diameter of 18.39 arc-seconds and a polar diameter of 16.49 arc-seconds.
Telescopic
Planets
Uranus
On the first of December, Uranus is high in the south, less than 1.5 degrees east of the dim star Phi Aquarii in the constellation Aquarius. Uranus is in good position for viewing in the early evening all month long. Uranus is about at meridian at sunset in the constellation Aquarius, and makes for the western horizon throughout the evening and early morning hours. The First Quarter Moon makes its closest pass for the month on the evening of the 5 th. By month’s end, Uranus is slightly past meridian in the south after sunset, prime for early-evening viewing this month. It is possible to observe Uranus through binoculars or telescopes as a pale blue, steadily-shining “star” in binoculars, and a small telescope at moderate-to-high power (about 75x or more) will reveal its disc (magnitude 5.9, and 3.43 arc-seconds on 12/31).
Neptune
Neptune is already above the horizon, high in the south after sunset in the constellation of Capricornus at the first of December. This will be a good month for viewing Neptune early in the evening. The waxing crescent Moon will bypass Neptune closely on the night of the 3 rd. The planet Venus approaches closely on the evening of the 26 th, and the crescent Moon pays another visit on the last two days of the month. On the last of the month, Neptune will be just under 3 degrees NW of Deneb Algedi / Delta Capricorni in eastern Capricornus. Neptune appears as a slightly deeper blue-hued “star” in binoculars than Uranus normally does, but also much less bright. A telescope will barely reveal a very small disc (magnitude 8.0, and 2.18 arc-seconds on 12/31) at high power (150x or more).
Dwarf
Planets
Ceres
The dwarf planet / asteroid Ceres is rising in Leo at about 5.5 degrees SW of the bright star Delta Leonis (Zosma), at about 11:30 p.m. at the first of December. On the evening of the 17 th the waning gibbous Moon bypasses Ceres, forming a kind of isosceles triangle with the planet Saturn. By the end of the month, Ceres is rising at a little before 10:00 p.m., a little under 3 degrees south of Delta Leonis. An observer will be able to view Ceres with a telescope (although a detailed star chart will be necessary to pinpoint its position), although far from glaringly, and even then Ceres’ disc is too small to be seen through any but the largest professional ground-based telescopes. Ceres should appear as a “dot” of a star, much like Pluto, only it will be visible with MUCH more modest viewing equipment! On the last day of the month, Ceres’ magnitude is 7.9.
Pluto
At the start of December, tiny Pluto is almost spent for evening viewing, setting at only about 6:30 p.m. and about 4.5 degrees NW of Mu Sagittarii. This is the worst month of the year to try to observe Pluto, which comes into solar conjunction on the winter solstice – the 21 st of the month. Thereafter, Pluto rises in the morning slightly before the Sun, but close enough to it to render it unobservable even under optimal conditions. Next month viewing should improve slightly for extremely dedicated pre-dawn observers!
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Meteor
Showers - http://comets.amsmeteors.org/meteors/calendar.html
Viewable
Comets - http://cometography.com/current_comets.html
Special
events - http://skytonight.com/observing/highlights/3310081.html
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