Enjoy the stars and hope the Mayans got it wrong
MAY 2012 be everything you want it to be and as Earth, Sun and Moon continue on their way, our calendars start another year. It is, however, the last year in the Mayan calendar, which allegedly brings the world to an end.
But more of that during the year, which starts with an almost quarter Moon. Full Moon follows on the 9th, after which the Moon wanes, with new Moon on the 23rd. The latest sunset occurs on the 7th and with the Sun still high in the sky, we can enjoy some of those glorious late summer evenings.
The Earth is closest to the Sun, known as perihelion, on the 5th. In theory this means that southern summers should be warmer than northern summers. However the difference is small, a mere five mil- lion kilometres closer than when at aphelion, furthest from the Sun, in July, and factors such as the distribution of oceans and land masses over the Earth’s surface mean there is no real detectable difference.
Venus, the evening star, is visible for the whole of January, while Jupiter can be seen high up in the north-west.
The northern evening sky is still dominated by the summer constellation, Orion. Between Orion and the horizon is the constellation of Gemini, with the twins Pollux and Castor, Pollux being a little brighter and higher.
To the west, left of Orion, the bright star Aldebaran in the small cluster of the Hyades is visible and further to the west is isilimela or the Pleiades in the north.
To the east, or right of Orion, is the brightest star in the sky, Sirius, with the Procyon between it and the horizon, the two forming a large triangle with Betelgeuse in Orion.
The second brightest star in the sky, Canopus, is high up in the south-east and is also known as Naka, the horn star, or E a dishwa: “it is carefully watched”.
The Moon can be used as a “marker” again this month. On the 2nd, a quarter Moon is just below Jupiter, and by the 5th it will be between isilimela and the small cluster of the Hyades. By the 8th a gibbous Moon will be below Betelgeuse and above the Twins in Gemini. Later in the month, in the west, a waning crescent Moon is to the right of Venus on the 27th. By the 30th it will be to the lower right of Jupiter and finally, on the 31st, it is close to isilimela once again.
To the south-east the Southern Cross and the Pointers are clearly visible and, high up, to the upper right, the Large and Small Magellanic Clouds can be seen if you are away from city lights. These are the two nearest galaxies to our own: a little smaller than our Milky Way. The former is about 160 000 light years away and the latter 180 000 light years away. A pair of binoculars should help you find the small Magellanic Cloud and on the lower right-hand edge is the globular cluster 47 Tucanae, looking rather like a “fuzzy tennis ball”.
It consists of about a million of some of the oldest known stars. There are many of these globular clusters and they are found in the “halo” surrounding our Milky Way galaxy. Many of the biggest and best of these clusters are visible in the southern skies.
As usual, there is an open night at the SA Astronomical Observatory and, in addition to looking through some telescopes, there is a talk entitled “Our strangely repulsive Universe: The dark energy mystery in cosmology” presented by Dr Chris Clarkson of the University of Cape Town, on January 14 at 8pm.