Wednesday, December 08, 2010
The Sky This Week - Thursday December 9 to Thursday December 16
Morning sky looking east as seen from Adelaide at 5:00 am daylight saving time on Sunday December 12 showing Saturn, Venus and the bright star Spica. Similar views will be seen elsewhere at the equivalent local time. Click to embiggen.
The First Quarter Moon is Monday December 13.
On the evening of Thursday, December 16 the waxing moon will pass in front of the moderately bright star eta Piscium. The star will pass behind the Moon just after midnight on the east coast (daylight saving time) and around 11:30 central states (daylight saving time. A list of exact times for major cities (uncorrected for daylight saving time) is here. The occultation will be visible to the unaided eye, but will be best in binoculars or telescopes.
Bright white Venus continues to rise above the eastern morning horizon and is now readily seen in the early morning sky. Venus, Saturn and the bright star Spica form a narrow triangle in the morning sky. Venus's crescent shape is easily seen in small telescopes. Venus will progressively decrease in size and wax towards "First quarter" over the coming weeks.
Saturn, Spica and Venus make an attractive morning sight. Saturn is almost high enough for telescopic observation.
Evening sky looking west showing the Mars and Mercury at 8:50 pm local daylight saving time on Monday December 13. Click to embiggen.
Mercury is lowering in the evening sky and will disappear in the twilight by the end of the week. On Monday December 13 and Tuesday December 14 Mercury and Mars are close. However, they will be difficult to see in the twilight, and you will need a clear, level horizon to have any chance at all.
Mars is now very difficult to see, low in the twilight below Mercury.
Jupiter can be readily seen from twilight until it sets in the early morning. Jupiter now spends most of the evening above the north-western horizon.
Jupiter is excellent in binoculars and small telescopes.
Jupiter and Uranus come even closer together, and are readily seen together in binoculars. Uranus is the second brightest object within a binocular field north of Jupiter (now that 20 Piscium has entered the binocular field), and is in fact bright enough to be (just) seen with the unaided eye under dark sky conditions. A binocular spotters map is here.
Jupiter's Moons are always interesting, in binoculars or telescopes of any size. There are lots of opportunities to see cool Jupiter Moon events (scroll down until you hit Jupiter).
The variable star Mira is visible to the unaided eye but fading. You can watch Mira fade over the coming week, before Moonlight interferes.
Comet 103P Hartley above the northern horizon at 10 pm ACDST (9 pm daylight saving time) as seen from Adelaide on December 12, similar views will be seen from other places at equivalent local time.
Comet 103P Hartley 2 continues to rise higher in the southern skies. It now rises well before midnight and is very high in the sky near Canis major and Sirius in the early morning.
The comet is fading, under dark skies binocular viewers will find it difficult to see the faint smudge near the open clusters M46 and 47.
By the end of the week it is no longer visible in binoculars.
Click the link for printable maps of comet 103P/Hartley.
The radiant of the Geminid meteor shower above the northern horizon as seen from Adelaide at 3:00 pm ACDST, similar views will be seen from other sites at equivalent local times.
The Geminid Meteor shower is at its peak from the point of view of Australian's on the mornings of Tuesday 14 December (13 December UT) and Wednesday 15 December. The best time to observe is between 1 and 4 am (daylight saving time, 12-3 am non-daylight saving time), with the highest rates between 2-3 am daylight saving time.
The Moon will have set by the time the Geminid radiant is high enough for decent meteor rates to be seen. In Australia we should see roughly a meteor every 3 minutes.
You can check predictions for you local site with the NASA meteor flux estimator (scroll down to 4 Geminids in the SHOWER box, make sure you have your location and date correct as well).
If you don't have a telescope, now is a good time to visit one of your local astronomical societies open nights or the local planetariums.
Printable PDF maps of the Eastern sky at 10 pm ADST, Western sky at 10 pm ADST. For further details and more information on what's up in the sky, see Southern Skywatch.
Cloud cover predictions can be found at SkippySky.
Labels: weekly sky