Welcome to the November night sky. Now that the clocks have gone back we are again in sync with solar time. This means that the Sun will be due south at local midday and of course at its highest at 12.00 hours for anybody close to the prime meridian of their time zone.
For us in Portugal and also UK, it is zero degrees longitude known as the Greenwich Meridian. For those of us to the east of this line, the Sun will seem to be a little fast and for those of us to the west it will be slightly slow.
The difference is not a lot, only amounting to four minutes of time for every degree of longitude and, at our latitude, one degree of longitude measures about 45 kilometres on the ground. This means that for every 10 kilometres east you travel, the Sun rises 1 minute earlier and for every 10 kilometres west you travel, the Sunset is 1 minute later.
The normally bright planet Venus is now lost in the glare of the Sun as well as Saturn – they are too low down in the east at nightfall to be seen this month. Also the red planet Mars is hiding low in the east at this time, glowing an obvious pink colour, possibly embarrassed by its recent “kiss” with a comet called ‘2013 Siding Spring’.
Directly overhead on late November evenings, we can see the autumn constellations of Pegasus and Andromeda. In this zone of the sky, and in the constellation of Andromeda, you can, from a dark sky location, see the nearest large galaxy to our own. This object, called by astronomers with its catalogue number of M31, is more than two million light years from Earth and is home to a thousand billion stars – this is about twice as many as in our Milky Way Galaxy!
Also, M31 is moving toward us at 300 kilometres per second and our two giant galaxies will merge together in around 4 billion years’ time, forming one of the largest galaxies in this part of the Universe.
November is known to astronomers as the month of the Leonid meteor shower. This shower is made up from dust of the tail of comet Swift-Tuttle that has an orbit of 33 years. This implies that every 33 years we may see a meteor storm with many thousands of shooting stars visible, as was the case in 1966 and again in 1999. So this year should be a normal one with a meteor visible every few minutes. The peak of the Leonid is on the night of the 17th to the morning of the 18th.
Although the origin point of this shower is in the direction of the constellation of Leo, the meteors can be seen in any part of the night as fast moving streaks as they hit Earth’s atmosphere at 160,000 miles per hour.
The moon is full on the 6th, last quarter on the 14th, new on the 22nd and first quarter on November 29.
By Clive Jackson
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Clive Jackson is the Director of the Camera Obscura (next to the Castle in Tavira), specialising in education and public outreach.
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