What’s In July’s Skies

By Matt Woods

Planets:

Mercury will make its reappearance in the second week of July, appearing very low on the western horizon. It will begin the week situated in the constellation of Cancer (The Crab), but as the month progresses, it will transition into the constellation of Leo (The Lion), drawing nearer to Venus, and the star Regulus. Venus can be observed in close proximity to Mars, positioned low in the constellation of Leo until the middle of the month when they gradually separate in the night sky. Meanwhile, Mars will continue its journey through the constellation of Leo, reaching its hind feet by the end of July.

Jupiter can be located between the head of the constellation of Cetus (The Sea Monster) and the front feet of the constellation of Aries (The Ram) during night-time. Saturn is also visible in the middle of the constellation of Aquarius (The Water-Bearer) in the night sky. Uranus rises late at night within the constellations of Taurus (The Bull), precisely positioned between Jupiter and the Pleiades Cluster. Lastly, Neptune can be found during the early night-time hours, situated between the top fish in the constellation of Pisces (The Fish) and the tail of the constellation of Cetus.

The Delta Aquarids Meteor Shower:

The Delta Aquarids meteor shower is set to reach its peak on the night of July 30th/31st, primarily favouring observers in the southern hemisphere, including those in Perth. This captivating shower remains active from the 12th of July to the 23rd of August, with the number of meteors seen per hour varying between 10 to 20. However, in 2023, the presence of a Full Moon in the night sky will result in reduced visibility of meteors from this shower.

The radiant point for the Delta Aquarids lies within the constellation of Aquarius, becoming visible from 08:00 pm (AWST) on the 30th of July. For optimal viewing, it’s best to wait until 03:00 am (AWST) on the 1st of August. The Delta Aquarids lack a prominent peak, but they consistently grace the night sky with their presence throughout their active period. It is believed comet 96P/ Machholz 1, once part of the Kreutz Sungrazing comets, is the source for the Delta Aquariids.

The Butterfly Cluster, also referred to as Messier 6 (M6) and NGC 6405, is an open cluster comprised of approximately 120 stars located within the constellation of Scorpius (The Scorpion). Positioned around 1,600 light-years away from Earth, the stars within this cluster are estimated to be between 55 and 100 million years old. Visually, the Butterfly Cluster appears slightly smaller than a Full Moon, with dimensions measuring 12 light-years in width and 25 light-years in length. It is crucial to avoid confusing M6 with its brighter neighbour, Ptolemy’s Cluster (M7), situated southeast of it.

While the discovery of the Butterfly Cluster by Giovanni Hodierna predates 1654, his data was not unearthed until the 1980s. It was independently discovered by Philippe de Chesaeux in 1745/6, and Messier catalogued it as M6 in 1764. Remarkably, the Butterfly Cluster remains one of the few objects within the Messier Catalogue yet to be photographed by the Hubble