In July, if you look towards the constellations Sagittarius and Scorpius on a clear night, you are looking in the direction of the very heart of our galaxy. Sagittarius, the Archer, is nestled within a mesmerisingly detailed part of the Milky Way. You can find it by first locating the Teapot asterism, which forms the constellation’s hub, close to a notably bright swathe of the Milky Way. A scan of Sagittarius with binoculars or a small telescope will reveal many rich star clusters and bright nebulae.
Scorpius is easy to find, sitting high in the sky and being one of the brightest constellations. Nearby is the slightly less prominent constellation Libra. This whole region is full of rich and beautiful star fields, which are a joy to explore using binoculars. If you turn to the constellation Libra, the Scales, look out for the second brightest star, which is called Zubenelgenubi – Arabic for “the Southern Claw” – and is the brighter component of the Alpha Librae system. It is a binary star system with the two stars in orbit around each other, and a pair of binoculars easily shows its two stars.
At this time of the year, Sagittarius offers some exceptional deep-sky objects. The globular cluster M22 is visible to the naked eye if you have good observing conditions. The Lagoon Nebula, or M8, lying above the spout of the Teapot, is a glowing cloud of gas. Other famous deep-sky objects in Sagittarius are visible through a telescope, including the Trifid Nebula, or M20. Beside Sagittarius, Scorpius contains the bright open clusters M6 and M7, which remain high in the sky this month. To the north in the constellation Serpens Cauda, the Tail of the Serpent, lies the open cluster M16 in the much fainter Eagle Nebula.
This month’s conjunctions, which is when two astronomical objects appear close to each other in the sky, include the moon and Jupiter on July 3, the moon and Saturn on July 25, the moon and Mars on July 30, and the moon and Jupiter again on July 31. Also, two meteor showers – the Alpha Capricornids and the Southern Delta Aquariids – will peak on July 29.
By Nerida Langcake
This article appeared in the July 2024 issue of the Mornington Peninsula Magazine.