Tuesday, July 25, 2017
The Sky This Week - Thursday July 27 to Thursday August 3
The First Quarter Moon is Monday, July 31. The Moon is at apogee, furthest from the earth, on August 3rd.
Mercury climbs higher in the evening twilight sky. It is now readily visible above the western horizon half an hour after sunset, and is obvious well over 60 minutes after sunset. Mercury is climbing away from the bright star Regulus but the pair are still obviously close together.
Similar views will be seen elsewhere in Australia at the equivalent local time (90 minutes after sunset). (click to embiggen).
Jupiter is rising before sunset and is now high above the northern-western horizon in the early evening at full dark. It is in between the bright star Spica, the brightest star in the constellation of Virgo, and the relatively bright star Porrima. Jupiter is now almost between Porrima and Spica. The waxing Moon forms a triangle with Spica and Jupiter on the 29th.
Opposition, when Jupiter is biggest and brightest as seen from Earth, was on April the 8th. Jupiter is rising before the sun sets and is visible until just before midnight. Jupiter is a good telescopic target from astronomical twilight on, and the dance of its Moons is visible even in binoculars. The following Jupiter events are in AEST.
Thu 27 Jul 18:42 GRS: Crosses Central Meridian Thu 27 Jul 21:53 Eur: Reappears from Eclipse Sat 29 Jul 20:21 GRS: Crosses Central Meridian Mon 31 Jul 17:51 Gan: Transit Ends Mon 31 Jul 20:16 Gan: Shadow Transit Begins S Mon 31 Jul 22:00 GRS: Crosses Central Meridian Mon 31 Jul 22:24 Gan: Shadow Transit Ends
Tue 1 Aug 17:51 GRS: Crosses Central Meridian Tue 1 Aug 20:46 Io : Transit Begins T Tue 1 Aug 21:57 Io : Shadow Transit Begins ST Tue 1 Aug 22:58 Io : Transit Ends S Wed 2 Aug 18:05 Io : Disappears into Occultation Wed 2 Aug 21:27 Io : Reappears from Eclipse Thu 3 Aug 18:36 Io : Shadow Transit Ends Thu 3 Aug 19:31 GRS: Crosses Central Meridian Thu 3 Aug 19:45 Eur: Disappears into Occultation
The inset shows the telescopic view of Saturn at this time. Similar views will be seen elsewhere in Australia at the equivalent local time. (click to embiggen).
Saturn was at opposition on the 15th, when it was biggest and brightest in the sky as seen from earth. Saturn is visible all night long. Saturn is a good telescopic target from 9 pm on. It is poised above the dark rifts in the Milky Way and is in a good area for binocular hunting. It continues to climb into the evening skies as the week progresses. Saturn's rings are visible even in small telescopes and are always good to view.
The constellation of Scorpio is a good guide to locating Saturn. The distinctive curl of Scorpio is easy to see above the north-eastern to northern horizon, locate the bright red star, Antares, and the look below that towards the horizon, the next bright object is Saturn.
Similar views will be seen throughout Australia at the equivalent local time (that is 60 minutes before sunrise, click to embiggen).
Venus is lowering in the morning sky and is visible in telescopes as a "Gibbous Moon". At the start of the Week Venus is below the head of Taurus the Bull and the bright star Aldebaran. by mid-week it forms the tip of the second horn of the Bull, and forms a triangle with Aldebaran and Beteguese.
Mars is lost in the twilight.
The Southern Delta-Aquarids meteor shower runs from from 12 July to 23rd August, peaking on Sunday July the 30th. The number of meteors you will see depends on how high the radiant is above the horizon, and how dark your sky is. This shower is fairly faint, with the highest rate of around a meteor every 4 minutes.
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
The crescent Moon was indeed a nice sight near Mercury and Regulus - even looking through the apartment towers near Sydney Airport !