The Sky This Week - Thursday October 17 to Thursday October 24

The Full Moon is Saturday October 19. Mars and Jupiter are prominent in the early morning. Venus is easily visible in the western evening sky close to the bright star Antares. Mercury and Saturn lower in the evening sky. Comet C/2012 S1 ISON visible in telescopes close to Mars. Orionid meteor shower peaks the morning of October 22.

The Full Moon is Saturday October 19.

Evening sky looking west as seen from Adelaide at 20:00 pm ACDST  on Saturday October 19. Venus is quite high in the evening sky above Saturn and Mercury. The insets shows the telescopic view of Venus and Mercury at this time. Similar views will be seen elsewhere at the equivalent local times.  Click to embiggen.

Venus  climbs higher in the evening twilight. It can easily be seen shortly after sunset (indeed, with a little effort you can see it before sunset). The brightest (spectacularly so) object above the western horizon it is visible up to three hours or more after sunset (depending on how flat your western horizon is).

Venus starts the week close  to the bright star Antares and continues its journey up the body of the Scorpion. It is a distinct gibbous shape in even small telescopes

Mercury  is still easily visible in the evening twilight. Mercury is lower in the evening sky this week heading towards the horizon, but remains prominent for the rest of the week.

Saturn is still visible above the western horizon in the early evening twilight in the constellation of Virgo. Telescopic views of the ringed world are progressively harder as the planet gets lower in the sky and deeper in the twilight. Saturn sets around 9:00 pm local daylight saving time.

Morning sky on Friday October 18 looking north-east as seen from Adelaide at 5:30 am ACST in South Australia. Jupiter is close to the star Wassat. Comet C/2012 S1 ISON is below Mars, and visible in amateur telescopes. The inset shows the view of Jupiter through a telescope at this time. Similar views will be seen elsewhere at the equivalent local time (click to embiggen).

Jupiter is in the constellation Gemini. Mars is is in the constellation of Leo.

Mars rises still higher in the morning twilight, and is visible well before twilight.  Mars starts the week close to the bright star Regulus and draws away during the week. Mars is closest to comet C/2012 S1 ISON on the 18th.

Jupiter is now well above the north-eastern horizon, above and well to to the left of Mars and near the birgt stars Castor and Pollux, the twins of Gemini. It is quite easy to see in the morning sky well into the twilight. During the week Jupiter rises higher and draws away from the moderately bright star Wassat. Jupiter’s Moons are now readily visible in binoculars.

Comet C/2012 S1 ISON is expected to become very bright in late November Early December. Currently it is visible in modest amateur instruments such as  8″ reflecting telescopes and has been imaged with DSLR cameras at high ISO values.  The image to the left shows a high power view of the region around Mars with ISON (expanded from the unaided eye view above).

While the comet is currently around magnitude 10 and should be around 9 by the 18th October, it is never very high at Astronomical twilight (5 and 7 degrees above the horizon in most of Australia). The horizon murk means that that it will be mid October before the comet is visible in smaller telescopes such as 4″ reflectors and late October for strong binoculars. You can get a PDF map suitable for printing here.

The comet is just below and to the right of Mars (56 arc seconds at closest approach on the 18th), making finding it relatively easy. Comet ISON was closest to Mars on October 1, but the orbital geometry means that from Earth it will appear closest on the 18th.

Morning sky facing north-east at 3:00 pm AEDST on 22 October, the Orionid radiant is indicated with a cross.

The Orionids are normally a worthwhile shower, best seen between 2-4 am, the radiant being just under Betelgueuse, the bright red star in Orion. This year the just past Full Moon’s light will significantly lower rates. The best viewing is the morning of the 22nd, when between 3-5 am under dark skies you should see about a meteor every 5-10 minutes.

There are lots of interesting things in the sky to view with a telescope. Especially with Venus so prominent in the sky.  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.