Wednesday, December 09, 2015
The Sky This Week - Thursday December 10 to Thursday December 17
The New Moon is Friday December 11.
Mercury returns low in the twilight.
Saturn is lost in the twilight.
The evening sky is now graced briefly by Mercury (well the twilight actually this week). Jupiter enters the evening sky in later December.
But while the evening is devoid of bright planets (aside, breifly, from Mercury), the summer constellations of Taurus (with the V shaped cluster the Hyades forming the head of Taurus the Bull and the beautiful Pleiades cluster nearby) Orion the Hunter and Canis Major with bright Sirius, the dog star, climbing above the eastern horizon.
Jupiter rises higher in the morning skies and is now easy to see in the pre-dawn dark.
Mars is higher in the morning skies and is visible in the early twilight.
Venus is easy to see in the morning twilight. It is a distinct "half Moon" shape and impressive in a small telescope.
Jupiter, Mars, Venus and the bright stars Regulus and Spica form a line in the sky this week. The waning Moon joins the line-up making for some very nice morning sights with The Moon visiting Jupiter, Mars and then Venus.
Comet C/2013 US10 joins the line-up. It is much fainter than anticipated and at magnitude 6.4 and fading, and being low to the horizon, it is probably a telescope only object.
The northern horizon at 4:00 am ACDST as seen from Southern Australia (northern Australia is similar but Gemini and the radiant is higher in the sky) on Tuesday December 15. The Geminid radiant is marked with a starburst . Similar views will be seen elsewhere in Australia at the equivalent local time. (click to embiggen).
The Geminids are a fairly reliable meteor shower and this year moonlight will not interfere.
Unlike the Leonids, where there is a very narrow peak of high activity, the Geminids have a broad peak and will show good activity well before and after the peak, and on the day before and after.
The radiant doesn't rise until just before midnight (daylight saving time) in most of Australia, so you will still have to disturb your sleep for this one. Australians should see a meteor every two to three minutes under dark skies in the early morning of the 15th, between 1:00 am and 4:00 am local time. You can find predictions for your local site at the meteor flux estimator (choose 4 Geminids and date 14-15 December, don't forget to change the date to 2015).
At 1.00 am in the morning AEDST (midnight, AEST) Castor (alpha Geminorum) is about two hand-spans above the horizon and 10 hand-spans to the right of due north. Pollux, the other twin, is less than a hand-span to the right again. The radiant is just below Pollux.
As well, Orion and the Hyades will be visible and bright Jupiter, Mars and Venus will be nearby. So it will be a quite nice morning for sky watching. Keep an eye out for satellites!
There are lots of interesting things in the sky to view with a telescope. 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 AEST, Western sky at 10 pm AEST. For further details and more information on what's up in the sky, see Southern Skywatch.
Cloud cover predictions can be found at SkippySky.
Here is the near-real time satellite view of the clouds (day and night) http://satview.bom.gov.au/
Labels: weekly sky