As we move into high summer, the sun turns southwards, our nights begin to lengthen and the moonless spell later in the month brings many of us our first dark skies of the summer.
The Plough is in the north west as the Summer Triangle reaches the high meridian. Formed by the bright stars Vega, Altair and Deneb, in the constellations Lyra, Aquila and Cygnus respectively, it is bisected by the Milky Way, which arches high across our eastern sky from Sagittarius and Scorpius low in the south to Cepheus, Cassiopeia and Perseus in the north east.
On the 16th of this month a partial eclipse of the Moon is visible from Britain. The full Moon rises around 9pm already partly obscured by the Earths shadow. The maximum eclipse occurs at 10.32pm, when the Moon is 65 percent obscured. It emerges from eclipse at midnight.
At the beginning of the month, you can catch Mercury and Mars very low in the north west after Sunset, in Gemini. They both form a line of four roughly equal objects with the constellations main stars. From left to right they are, Mercury (magnitude +1.2), Mars (magnitude +1.8), Pollux (magnitude +1.2) and Castor (magnitude +1.6). But they will have disappeared into the twilight glow by mid-July.
On the 4th of this month at 9.45pn, look low in the twilight to the north west, preferably with binoculars, to see the thinnest crescent Moon with Mercury and Mars.
The main action this month is taking place in the southern sky, where Jupiter is blazing brilliantly at magnitude –2.5 in Ophiuchus, until it sets around 2.30am. The star to its lower right in Antares, in Scorpius.
To the left of Jupiter is Saturn; which will be at its brightest and closest to the Earth on the 9th July. Even then it’s ten times fainter than Jupiter at magnitude +0.1. Visible all night long, the ring world lies in Sagittarius. With a telescope you should see its magnificent rings and giant moon Titan. On the 12th July, the Moon forms a triangle with Jupiter to the left and Antares to the lower left.
Next comes Neptune, rising about 11pm in Aquarius To spot this faint world with a mere magnitude +7.8, you will need binoculars or a telescope.
Uranus appears above the Horizon around 0.30am, at magnitude +5.8 in Aries.
Just before dawn, you may just catch brilliant Venus, very low on he north eastern horizon. Shining at magnitude –3.9, it rises just after 4am.
On 28th July a lovely crescent Moon lies just to the left of Aldebaran and the Hyades with the Pleiades above
Around the 28th and 29th of this month we will see the annual peak of the Delta Aquarid meteor shower. It might be possible to see up to 20 meteors per hour. The best time to see this shower will be between midnight and dawn. Delta Aquarid meteors may come from Comet Machholz which was discovered by Donald Machholz in 1986.
Phases of the Moon for July:-
New Moon 2nd
First quarter 9th
Full Moon 16th
Last Quarter 25th