Astroblog: The Sky This Week - Thursday July 27 to Thursday August 3

Tuesday, July 25, 2017

The Sky This Week - Thursday July 27 to Thursday August 3

The First Quarter Moon is Monday, July 31. Mercury climbs above Regulus. Jupiter and the bright star Spica are nearby in the evening sky. The Moon forms a triangle with the pair on July 29. Saturn is visible all night in the heart of the Milky Way and is close to the Moon on August 3. Venus dominates the morning sky below the head of Taurus the Bull. The Southern Delta Aquariid meteor shower peaks on the 30th.

The First Quarter Moon is Monday, July 31. The Moon is at apogee, furthest from the earth, on August 3rd.

Evening sky on Saturday July 29 looking west as seen from Adelaide at 18:29 ACST (60 minutes after sunset). Mercury is above the western horizon above Regulus.

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.

Evening sky on Saturday July 29 looking north-west as seen from Adelaide at 18:59 ACST (90 minutes after sunset). Jupiter is above the horizon between the bright star Spica and the relatively bright star Porrima. The waxing Moon forms a triangle with Spica and Jupiter. The inset shows the telescopic view of Jupiter on Saturday July 22 at 18:55 ACST .

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

Evening sky on Thursday August 3 looking north as seen from Adelaide at 20:50 ACST, when Saturn is at its highest. Saturn is almost overhead high above the northern horizon. The Moon is just below Saturn.

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.

Morning sky on Saturday July 29 looking east as seen from Adelaide at 6:19 ACST (60 minutes before sunrise). Venus is dazzling below the bright star Aldebaran and forms a triangle with Aldebaran and Betelguese. The inset shows the telescopic view of Venus at this time.

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.

Evening sky looking east from Adelaide at 2 am local time on July 30th in South Australia. The cross marks the radiant (the point where the meteors appear to originate from) of the Southern Delta Aquariids. Similar views will be seen elsewhere at the equivalent local time (click to embiggen).

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