Case Rijsdijk’s What’s up?

The month starts with a waxing (growing) gibbous Moon which becomes full on the 6th. New Moon is on the 21st, with the first crescent becoming visible on the 23rd. There is a partial eclipse of the Moon on the 5th, but it's a penumbral eclipse, meaning that the Moon passes through the half shadow of the Earth. At best, the full Moon won't be quite as bright as usual, half will be in the partial shadow at about 21:30.

The winter solstice, when we have the shortest day and longest night, is on the

20th. Although it is the shortest day it is not the time of earliest sunset and latest sunrise. These actually occur on June 12th and 30th; due to the geometry of the Earth's orbit around the Sun and the inclination of the Earth's axis. It is also when the Sun is lowest in the northern sky at noon and its light reaches furthest into north-facing homes.

The Southern Cross is very high in the south and unmistakable with the two bright Pointers, Alpha and Beta Centauri, on its left, and the long axis of the Cross pointing directly down. The Milky Way stretches across the sky on either side of the Southern Cross. To me it is still one of the most spectacular sights, and a pair of binoculars will reveal much detail. Beneath the Cross just above the horizon are two fuzzy patches. These are the large and small Magellanic Clouds, two small galaxies closest to our Milky Way.

It also features in indigenous starlore (mythical stories about the stars and star patterns) across the world. The Australian Aborigines saw in it the "Emu in the Sky"; the head of the Emu is the "Coalsack", the dark patch between the Southern Cross and the Pointers. In South Africa, one story says that a girl threw the coals and ashes of a fire into the sky to tell her lover where she was.

Mercury is the only planet low in the west just after sunset. No other planets are visible till after midnight, when Jupiter, Saturn and Mars make their appearance. Venus joins them after mid-month so that four planets will become visible in the morning sky.

ESA Hubble Image: Nasa The Porpoise Galaxy. The image shows two galaxies; the upper was a normal spiral galaxy, like the Milky Way, the lower is a massive elliptical galaxy whose strong gravitational attraction has pulled the upper galaxy towards it, rather like a porpoise taking a dive. Others say it’s like a penguin protecting its egg. The blue colour is due to the birth of new stars and in about one billion years, they will merge into one large galaxy.