The Sky This Week - Thursday September 20 to Thursday September 27

The Full Moon is Tuesday, September 25.  4 bright unaided eye planets can be seen in the evening sky. Venus is high in the early evening sky and is at its greats brightness on the 21st.  Venus and Jupiter are at their closest on the 22nd.  Saturn and Mars are visible in the evening skies. The Moon is close to Mars on the 20th. Comet 21P may be seen in binoculars in the morning

The Full Moon is Tuesday, September 25.   The Earth is at Equinox, when day and night are of equal length, on the 23rd.

Evening twilight sky on Saturday September 22 looking west as seen from Adelaide at 19:36 ACST (90 minutes after sunset). Venus is high above the horizon and is at its closest to Jupiter. Jupiter is now high in the western sky as well.

The insets shows  simulated telescopic views of Venus as seen with a 5mm telescopic eyepiece on Saturday September 22 and Jupiter on Friday September 21, At this time Io and its shadow are transiting Jupiter. Venus is a clear crescent in small telescopes.

 Similar views will be seen throughout Australia at the equivalent local time (90 minutes after sunset, click to embiggen).

Brilliant Venus is visible high in the evening until well after full dark. Venus is visible to the unaided eye from before sunset, easy to see shortly after sunset and can viewed well after 90 minutes after sunset. This week Venus is at its closest to Jupiter on the 22nd, and at its brightest on the 21st.

Whole sky view of the evening sky on Saturday September 22 as seen from Adelaide at 19:36 ACST (90 minutes after sunset).  Four bright planets are visible in the evening sky.

Similar views will be seen throughout Australia at the equivalent local time (just after 90 minutes after sunset, click to embiggen).

Evening sky on Thursday September 20 looking north  as seen from Adelaide at 19:32 ACST (90 minutes after sunset). Saturn and Mars are clearly visible. The Moon is close to Mars on the 20th. The insets are simulated telescopic views of Saturn and Mars as seen with a 5mm telescopic eyepiece.

Similar views will be seen throughout Australia at the equivalent local time (90 minutes after sunset, click to embiggen).

Location of comet 21P Giacobini-Zinner as seen from Adelaide at astronomical twilight (4:55 am, 90 minutes before sunrise) looking north-east on Saturday 15 September.

The location of the comet is marked with a red cross. Similar views will be seen elsewhere in Australia at the equivalent local time (90 minutes before sunrise,click to embiggen).

The comet will be visible as a fuzzy dot in binoculars.

 Venus  is  readily visible above the horizon in the early evening.  It is bright enough to be visible from just on sunset and to well past 90 minutes after sunset at full dark, when it is four hand-spans above the horizon.  During the week Venus heads towards Jupiter. Venus is close to the crescent Moon on the 13th.

Mercury is returns to the evening skies but is hard to see low on the horizon 15 minutes after sunset.

Jupiter  is high in the early evening sky above the western horizon. It was at Opposition on the May 9th, and is still visible most of the night. It is  a good telescopic object in the early evening and is setting around 11:00 pm local time. This week Jupiter continues to move away from the bright star alpha Librae (Zubenelgenubi) and is close to the crescent Moon on the 14th.

 Mars is in Capricornius and is readily seen in the evening. Mars was at opposition last month on July 27th,  when it was biggest and brightest as seen from Earth. This was the best opposition since 2003. However Mars will remain bright and large in even small telescopes for some time. In a telescope you may see a few features as the huge dust storm sweeping the planet continues to subside.  A guide to observing Mars at the time is at my Mars Opposition page. Mars is close to the Moon on the 20th.

Saturn is now high in the northern evening sky in the early evening, and is a good telescopic object in the mid to late evening sky. It was at opposition, when Saturn is biggest and brightest as seen from Earth, on June the 27th. It is within binocular range of  the Trifid and Lagoon nebulae. With the full  Moon in the sky the nebulae are hard to see.

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/