What’s up? Case Rijsdijk’s
New Moon occurs tonight, the 11th, with the first crescent becoming visible. Full Moon will be two weeks later, on the 25th.
During the month, the Moon can be used as an indicator for finding objects in the night sky. On the 14th, for example, a crescent (less than quarter) Moon will be close to Saturn; on the 20th, a gibbous (more than quarter) Moon will be close to the star cluster the Pleiades, or isiLimela.
Venus is often called the Evening Star - a misnomer. It is a planet, not a star, and it can also appear in the morning skies. Looking in an easterly direction, Venus shines very brightly for most mornings before sunrise this month. On the 27th, Mercury and Mars are very close together after having danced around the morning skies. Then on the 31st there is a pretty asterism to end January with; Venus heads up three planets in order of brightness: Venus, Mars and Mercury.
The northern evening sky is dominated by the summer constellation Orion. For the Tswana, the stars of Orion's sword were "dintsa le Dikolobe", three dogs chasing the three pigs of Orion's belt. Warthogs, that frequently have litters of three, have their litters while Orion is prominent in the sky. Somehow this makes more sense to me than the hunter - who is upside down here in the Southern Hemisphere anyway!
Between Orion and the horizon is the constellation of Gemini with the twins
Castor and Pollux; Pollux being a little brighter and higher than its twin, Castor. To the west (left) of Orion the bright star Aldebaran in the small A-shaped cluster of the Hyades is visible and further to the west is isiLimela or the Pleiades.
To the east (right) of Orion is the brightest star in the sky, Sirius, with Procyon between it and the horizon. The second brightest star in the sky, Canopus, is high up in the southeast and is also known as Naka, the horn star, or "E a dishwa": it is carefully watched. For those readers who like geometry, there is a beautiful equilateral triangle between Betelgeuse, Sirius and Procyon, also known as the Great Southern Triangle. See sketch.
To the south-west the Southern Cross and 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: both 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 one of the biggest and brightest globular clusters, 47 Tucanae, looking rather like a fuzzy tennis ball, on the lower right edge of the small Magellanic Cloud. It consists of tens of thousands of some of the oldest known stars. There are many of these globular clusters and they are found in what is called the "halo" surrounding our Milky Way galaxy. Many of the biggest and best of these globular clusters are visible in the southern skies, as are 18 of the 20 brightest stars.
The Southern Cross can also be used to find the South Celestial Pole (CSP). If one extends both the long axis of the Cross and the perpendicular bisector of the Pointers, the two lines will intersect at the SCP.