Now that the longest day is behind us, we can begin to look forward to the nights lengthening, although still warm for relaxed observing.
Planets
Mercury, the innermost planet, may be glimpsed low down on the western horizon from late July. On the 25th, the crescent Moon lies a little to the east of Mercury, so use this as a guide to spotting the tiny planet. Venus continues to shine in the pre-dawn sky from 03:30 and is sitting within the constellation of Taurus. On the 20th July, the waning crescent Moon sits a little to the south of Venus.
Jupiter can still be spotted low in the south west after sunset. It’s always worth pointing a small telescope or binoculars towards Jupiter as the four main moons can easily be seen as they orbit the giant planet.
Saturn rises at around 22:30 with the rings showing superbly; as Saturn orbits its way around the solar system, the rings tilt towards and away from us and at the moment they are tilted favourably. Binoculars show that the planet is not a true globe, whilst a small telescope shows the rings clearly.
Constellation: The Summer Triangle
This month we have three constellations on our list which together make up a pattern known as the Summer Triangle, a great way to find your way around the night sky. Vega, a blue white star, which also happens to be the second brightest star in the northern hemisphere, is the most prominent star of the group, and the principal star of the constellation Lyra (the Lyre), which we featured last month. Next is Deneb, the tail of Cygnus the Swan and finally Altair, the head of Aquila the Eagle. Together these three stars make up this “Summer” triangle which is one of the most well-known patterns in the sky. To find it with the map, from early July look due east at around 23.00 and see if you can spot Vega shining brightly. Now look a little to the east and see if you can spot Deneb; follow a line from Deneb down to Altair and you have the Summer Triangle! So how does this help us? Well, having found Cygnus, the “head” of the Swan is the lovely double star Albireo; point a telescope at it and you will see 2 stars, one a yellow gold colour and the other a blue colour.
Following Albireo gently southward with binoculars, you may well be able to spot another pattern of stars known as the Coathanger, as it looks exactly like its description! The Coathanger is a chance alignment of stars known as an “asterism”, and there are many to be found in the night sky.
