Brought to you by Dr. Roy Gretton, Journal Editor of The Nottingham Astronomical Society.
Contact details are on the Nottingham Astronomy website: https://nottinghamastro.org.uk/
Please note, the NAS new permanent venue for our main meetings on first Thursday of the month is Nottingham Emmanuel School, Gresham Road, West Bridgford, Nottingham. NG2 7YF
As July gives way to August true darkness returns to our sky, at first for a brief period either side of 1 am, but later in August it extends to several hours every night. This is the time of year when the Milky Way is seen at its best, flowing down from the constellation of Cygnus, the Northern Cross, high in the south, through Aquila before disappearing below the southern horizon in the constellation of Sagittarius. Two or three generations ago the Milky Way was a familiar sight to most people, but under our lightpolluted skies very few people today even notice it. If you happen to be visiting the south coast of England or Wales this August, and can get away from the bright lights of a town, the southward view over the sea can be spectacular on a clear moonless night, because you are looking toward the centre of our galaxy. You won’t, of course, be able to see the supermassive black hole that lies there, but you will be looking at the richest part of the Milky Way, full of stars, starclusters and nebulae. You may even be able to spot another kind of “black hole”, because the plane of the galaxy is home to thick clouds of dust (“dark nebulae”) that block out some of the starlight, giving the appearance of holes in the Milky Way. The most famous of these is known as the “Coal Sack”, but it is too far south to be visible from Britain.
Our galaxy is spiral in shape and is constantly turning, stirring up its contents over many millions of years. One rotation requires over 200 million years to complete, so we were last on this side of the galaxy when the dinosaurs were just setting out on their long domination of the Earth.
The Perseid meteor shower
Much closer to home are the grains of space debris that continuously fall into our atmosphere and at night give rise to “shooting stars”. Sometimes the Earth passes through a swarm of these particles left behind by a comet that happened to cross our orbit. The Perseids are caused by debris from Comet Swift-Tuttle which was discovered 1862 and orbits the Sun every 133 years. Maximum meteor activity is expected in the early morning of August 13th. This year conditions are highly favourable for seeing the Perseids, as the Moon will be a thin crescent that will hardly affect observations. My advice, given clear sky on the night of August 12th-13th, is to recline in a deckchair or lounger, let your eyes adapt to the dark for a few minutes, and enjoy the display. Perseid meteors will appear to be coming from the east, but you may spot one in any part of the sky.
The Planets
Evenings are now almost a dead loss for observing planets. Venus, which has been so spectacular in the evening sky so far this year, will have disappeared before the end of July, and will be in conjunction with the Sun on August 13th. Mars, too, has practically disappeared from the evening sky. Mercury will spend the period as an evening object, but mostly too close to the Sun to be observed; all of which means that we shall have to turn our attention to the early morning sky to get the best chance of seeing planets. In late July Saturn will be rising at midnight, to be followed by the much brighter Jupiter at 1 am. By the end of August Jupiter will be rising at 11 pm to become the brightest object in the night sky (apart from the Moon) until Venus starts to reappear as a morning object about an hour before dawn.
Phases of the Moon
| JULY | AUGUST | |
| Full Moon | 3rd | 1st & 31st |
| Last Quarter | 10th | 8th |
| New Moon | 17th | 16th |
| First Quarter | 25th | 24th |
