24 January 2007

Close Encounters

Winter skies are beautiful for the richness of the heavens we see. The king of the winter sky is the bright distinctive constellation Orion the Hunter which rises from the south-east and dominates the southern sky during the winter months. Winter can be uncomfortably cold for long astronomy sessions, however, so rather than staying out late in the cold, I find myself enjoying the evening sky when the light changes and the stars emerge and the air has not yet cooled down. For example, on clear evenings from Ocean Beach I enjoy spotting stars and planets as darkness falls.

During the latter part of January and into February the two inner planets dominate the sunset sky. Minutes after sunset you can find Venus in the slowly fading sunset sky. It is very bright and getting brighter over the coming months. Mercury, however, is a difficult planet to find. It never gets very high up in the evening or morning sky and it never shines as bright as Venus. However, over the next week or two you will have a chance to see it twinkling in the darkening sunset sky with Venus as your guide to help find it. You will definitely need a clear western horizon for this.

Part of the joy of astronomy for me is to see these special moments when two planets pass near each other or the moon forms a beautiful pattern with stars and planets. If the skies are clear and you have a chance, enjoy this special time when Mercury and Venus share the stage.