AUGUST is both a supermoon and blue moon month and we can also look forward to the Perseids, one of the most important meteor showers of the year, writes Martin Lunn.

There will be two full moons this month falling on August 1 and the 31. The second full moon in a month is referred to nowadays as a ‘Blue Moon’. The Moon takes around twenty-nine and a half days to orbit the Earth once and except for February all months have either thirty or thirty-one days, meaning it is possible to have two full moons in a calendar month.

This use of the term ‘blue moon’ only goes back to the 1940s when a letter, sent to the American astronomy magazine ‘Sky and Telescope’ which incidentally is still published, asked the question ‘what is a blue moon?’. The answer was that it is the second full moon in a calendar month. The publishers of the magazine, realising that their answer was unproven, retracted their original statement. However, it was too late; the genie was out of the bottle, and for the last seventy-five years everyone has accepted this definition.

I have my own theory about the term ‘blue moon’. Each month I give the name of the next full moon, and as I often say, these names go back to the times of the monastic period in Britain around 1,000 years ago. The monks, who were amongst the cleverest people around during the middle ages due to their vast monastic libraries, knew full well that in some years there were thirteen full moons rather the normal twelve.

Monks liked order in their lives. They kept diaries and special dates were always marked in red ink; you may have have heard of the phrase ‘a red letter day’ which is a monastic saying going back over 1,000 years. I just wonder if, when this thirteenth full moon occurred, it was marked in diaries in blue ink as a source of irritation because it messed up a very orderly system. I once checked the reference library in York minster without success, but a future researcher will check the Vatican library and discover a monk’s diary with a full moon marked in blue ink!

In August we will see the second of the four supermoons visible in 2023. When the Moon rises on August 1 and 31 it will be closer to the Earth than normal, and consequently will appear to be seven per cent larger than usual. This will make it a wonderful sight. Of course, cloud can spoil the occasion, but with two supermoons in August and another in September, we would be very unlucky not to see at least one of the three.

The average distance between the Moon and the Earth is 238,900 miles, (384,472km). When the moon is closer than that we have a supermoon. The August 1 supermoon will be 222,158 miles (357,530km) while the August 31 supermoon will be slightly closer at 222,043 miles (357,344km).

The truly dark skies return during August, which can be a spectacular month. If you are looking for the Plough you will find it to the north west of the overhead point, with Cassiopeia at about the same height in the north east. Vega, one of the summer triangle stars, is now practically overhead and the other two stars, Deneb and Altair, are also very prominent. When looking at Deneb you will see the Milky Way behind it; a wonderful summer sight as it appears almost overhead at this time of the year. If you continue to follow the path of the Milky Way down towards the southern horizon you will reach the constellation of Sagittarius the Archer. Sagittarius is not seen well from Britain because it is so low in the sky, but if you look towards it you will also be looking towards the centre of our galaxy. The rest of the southern area of the sky is difficult to navigate because it is taken up by formless and faint constellations including Hercules, Ophiuchus and Serpens. The only bright star in this area is the red star Antares in Scorpius, which is still just visible and can be found low in the south west.

If you are up and around in the early mornings during August it is possible to see the first signs of the autumn sky with the Square of Pegasus just appearing above the horizon. Pegasus will become one of our ‘anchor ‘groups in the autumn.

The planets in August The gas giants Saturn and Jupiter can both be seen this month. Saturn, the famous ringed planet, appears as a yellowish looking ‘star’ low in the sky in the south. You will need a telescope to see the rings. Jupiter, the largest planet in the solar system, is rising around 11 pm in the south east, but will appear earlier in the evenings later in the year.

The other three naked eye planets; Mercury, Venus and Mars are all too close to the Sun to be seen.

Meteor showers The most anticipated meteor shower of the year, the Perseids, will peak on the night on August 12/13 when around 80 meteors per hour might be seen. At the present time only the Geminids in December and the Quadrantids in January produce more meteors. Some meteors will be seen a few days before this date and a day or so after.

Many people know meteors as shooting stars, but they have nothing at all to do with stars. They are tiny grains of dust that burn up when they enter the Earth’s atmosphere. They travel at speeds ranging from 20 to 50 miles per second and we see the result of their destruction in the form of a brief streak of light across the sky.

Although a few sporadic meteors can be seen on any night of the year, there are periods when many can be seen, and these are referred to as meteor showers. These meteors are connected with comets. Comets are essentially very large dirty snowballs travelling around the Sun. Comets leave a trail of dust behind them and if the Earth happens to pass through one of these dust trails we see a meteor shower. There are several major meteor showers during the course of the year.

The Perseids are connected with comet Swift-Tuttle, which was discovered by the American astronomers Lewis Swift and Horrace Tuttle in 1862. This comet takes 133 years to obit the Sun. The Perseid meteor shower has a very long history. The meteors are called Perseids because if you track their paths across the sky they all appear to come from the constellation of Perseus. It should be possible to see the Perseids after about 11pm, at first from the north east, but as the night goes on, all over the sky. An old name for the Perseid meteors shower is the Tears of St. Lawrence. In 258 in Rome a Christian named Laurentius, sometimes referred to as Lawrence, offered the Roman Emperor Valerian all the wealth of the empire. Valerian believed that he meant gold and treasure but Laurentius meant the people of the empire. Valerian was very annoyed when he did not get the treasure he was expecting and had Laurentius killed in a most horrible way by having him roasted alive.

The execution was on August the 9th 258, and when, the following evening, the Perseids came through on schedule, people thought these meteors were tears from heaven, hence the name ‘The Tears of St. Lawrence’.

The story then goes forward to August 1535 when the French explorer Jacques Cartier was exploring the part of the then ‘new world’ that today we call Canada. While camped beside a large river he saw the Perseid meteor shower. Knowing the story of St. Lawrence and being the first European there, he named it St. Lawrence River. This great river in Canada owes its name to a French explorer and a meteor shower.

Phases of the Moon for August 1 Full Moon, 8 Last Quarter, 16 New Moon, 24 First Quarter, 31 New Moon (Blue Moon) This month’s full moon is called the ‘Sturgeon Moon’. This is the month when, in past centuries, sturgeon would have been caught in the rivers of Britain. They were considered to be royal fish and the first caught had to be given to either the King or the