By Clive Jackson
Welcome to the October night sky. This is the month that sees the clocks go back. It will happen on the last Sunday, the 27th. The clocks will then be back in sync with the Sun or at least for anybody living on the zero degrees meridian. If you are east of 0º the Sun will be slightly fast and if you are west it will be slightly slow.
October has only two bright planets visible, the first is Venus, very low down on the west south-western horizon just after sunset. The second is Jupiter, rising soon after midnight in the northwest in the constellation of Gemini.
The thin crescent Moon is close to Venus on the early evening of the 8th. As Venus disappears below the horizon in one direction, you will be able to see, over in the northwest, the small but very pretty star cluster of the Pleiades, or Seven Sisters, rising. This is a sure sign of winter on its way.
The night of the 21st sees the peak of the Orionid meteor shower. These fast-moving yellowish shooting stars are debris from the famous Halley’s Comet and enter our atmosphere at 150,000 miles per hour but burn up at high altitude.
Rising in the east at around 2am is the constellation of Leo, and the comet Ison is there but not yet visible with the unaided eye. This comet was expected to be well visible over the Christmas period, but it is not performing as expected, as often is the case with comets.
There is another important comet called Siding Spring that is heading for a very close encounter with the planet Mars in exactly one year’s time, at 7pm on October 19 2014. This comet has a very small chance of actually hitting the red planet. The most likely scenario is that it will miss Mars by 100,000 kms distance.
In any case, the planet will pass through the outer dust cloud, and the space probes that are on or orbiting Mars should see a spectacular meteor shower at that time.
Comet impacts on uninhabited planets are considered a good thing generally as they transport water to the surface and help to maintain the atmosphere in the case of Mars.
The new Moon is on the 5th, first quarter on the 11th, full Moon on the 18th and last quarter on October 26.
Download the Algarve Skies Chart by clicking on the link below to download a PDF of the chart.
http://www.the-resident.com/portugalresident/pdf/ALGARVE_RESIDENT_ALGARVE_SKIES_OCTOBER_2013.pdf
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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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