The moon is new March 1 and again March 30. Jupiter is five degrees away March 10. Full moon occurs March 16, and, in a repeat of last month, Spica, Mars and Saturn join in March 18, 19 and 20. Again, Saturn's encounter is an occultation south of the equator. Venus, Mercury and Neptune close in March 27 and 28 in the early morning eastern sky. The moon's average distance from Earth is 400,000 kilometres.
Mercury joins Venus in the early morning, eventually orbiting around to the far side of the sun. This apparition greatly favours Southern Hemisphere viewers and a clear horizon is a must to see this fleeting planet. Mercury's average distance from the sun is nearly 58 million kilometres.
Venus, the Morning Star, shines brightly above Mercury in the east before sunrise. Venus orbits at an average distance of a little over 108 million kilometres.
Mars continues near Spica in the late evening to the southeast. Its apparent motion stops going eastward and begins retrograding (westward) March 1. Remember, it's the Earth's faster orbital motion that causes this apparent anomaly, as all the planets move in a counterclockwise orbit, if viewed from above. The moon is within three degrees March 19. Mars orbits the sun about 228 million kilometres out.
Jupiter is high in the south as the sky darkens, well placed for telescopic observation in the constellation Gemini. The gas giant begins retrograde motion March 6, and reaches its greatest northerly declination (height in the sky) in the 24-year period 2002-2026. Jupiter goes around the sun at a distance of over 778 million kilometres.
Saturn begins retrograding March 3. The Ringed Planet rises after midnight, and has a close encounter with the moon March 20. Saturn goes around the sun about 1.4 billion kilometres out.
Uranus is not visible during March. Its orbit is 2.87 billion kilometres.
Neptune is only visible late in the month, and even then only in the very early morning and by using a telescope. The blue-green planet orbits our star at 450 billion kilometres.
In the western evening sky, look for the Zodiacal Light in the latter two weeks of the month.
- James Edgar has had an interest in the night sky all his life. He joined The Royal Astronomical Society of Canada in 2000 and is now assistant editor and a contributor to the Observer's Handbook, production manager of the bimonthly RASC Journal, and the society's national secretary. He was given the RASC Service Award at the 2012 General Assembly in Edmonton.
