TRADITIONALLY, September was the month when crops were harvested; a time of year that was vital to local economies across the country.

Harvesting the crops as quickly as possible was crucial in ensuring that people had enough food for winter. This is why the full moon we see this month is probably the best known of all: the Harvest Moon.

This won’t be the usual Harvest Moon, however, but a Super Harvest Moon. This is the second of the four super moons this year. On September 18 when the Moon is full it will be slightly closer than normal and hence a supermoon. The supermoon in October will be the closest of the year.

At this time of year, when the Sun sets, the Moon rises, which in pre-mechanised times meant that harvesting was not restricted to the normal hours of daylight. In medieval times all the harvesting was done by hand so it took much longer than it does today.

The moonlight allowed entire villages to work throughout the night - of course, the Moon does not shine, so ‘moonlight’ is really reflected sunlight. The extra light a couple of days either side of full moon helped farmers to harvest enough to survive the coming winter and have enough to sell at the markets, which were then the lynch pins of the economy.

The nights are drawing in now. September is a transition month for the night sky, when the summer’s bright constellations start to give way to autumn’s finest, primarily the constellation of Pegasus. By mid-month, the sight of the Great Square of Pegasus, clear of the eastern horizon as darkness falls, is a sure sign that autumn is upon us, with the promise of cooler evenings.

We are not completely done with the summer stars however, as the Summer Triangle of Altair, Deneb and Vega still dominates the early evening sky. Vega, in the constellation of Lyra the Lyre, is still very high but no longer overhead; Deneb, in the constellation of Cygnus the Swan, is now at its highest being nearly overhead, while the most southerly of the three stars, Altair, in the constellation of Aquila the Eagle, can still be seen easily but is now lower in the sky.

The other bright star of the summer skies, the red star Antares in the constellation of Scorpius the Scorpion, has now set. A large part of the south western sky is occupied by the large but faint constellations of Hercules, Ophiuchus the Serpent Bearer and Serpens the Serpent. As the month progresses and these constellations move towards the horizon, they will be replaced in the south by the equally faint constellations of Capricornus the Sea Goat and Aquarius the Water Bearer.

The Plough, also known as Ursa Major or the Great Bear (and to the Americans the Big Dipper) is now getting lower in the northern sky, which means of course that the ‘W’ of Cassiopeia is getting higher. These two groups are on opposite sides of the North Star, or to give it its proper name, Polaris. To find Polaris, start with the two stars furthest from the handle of the plough and draw a line from the right hand star through the left hand star. If you then continue the line you will come to the North Star. If the line is continued further, you reach Cassiopeia.

The Plough is one of our signpost constellations in the night sky and by using the three stars of the handle and curving round and down it is possible to see, low in the north west sky, the bright orange star Arcturus, which has been visible since spring. This will be the last month when you can see Arcturus this year.

Capella, in the constellation of Auriga the Charioteer, is now becoming more prominent in the northern sky. In the winter months Capella will occupy the overhead point in the sky which is marked by the bright star Vega during the summer months.

The Planets in September: Some of the naked eye planets return to the evening sky this month, so we no longer have to wait until after midnight to see them.

If you look to the south around 9pm when it becomes dark, you will see a bright yellowish looking ‘star’. This is the famous ringed planet, Saturn. You won’t be able to see the rings unless you have a telescope. Two other planets, Jupiter and Mars will be rising in the south east around 11pm.

The other two naked eye planets, Mercury and Venus, are still too close to the Sun to be seen.

Meteor Showers:

There are no major meteor showers predicted for this month.

Phases of the Moon for September:

New Moon 3, First Quarter 11, Full Moon 18, Last Quarter, 24 On the night of September 16 the Moon will be seen on the right of Saturn, and on the following night it will be on the left of the planet.

The Autumn Equinox On September 22 the Autumnal Equinox occurs, marking the start of autumn in the northern hemisphere and of spring in the southern hemisphere. The word 'equinox' comes from the Latin words, 'aequi', which means 'equal' and 'nox', which means 'night'.

At this instant the Sun lies above the equator and both poles of the planet are illuminated, meaning that on this day the length of daylight and night time are the same.