Witness the Crescent Moon Pass Saturn This Week

A slender crescent moon slides past Saturn this week, offering a rewarding conjunction. It will be the perfect way to start your evening, a little quiet contemplation of the night sky as the evening twilight gives way to full darkness. The chart shows the view looking south-west from London at 18:00 GMT, although the pair will have been visible from the moment dusk begins to gather. The moon will be a little less than four days old. With just 15% of its visible surface illuminated, it should also be a good opportunity to see the “Earthshine”. This is when the unlit lunar surface is faintly revealed by sunlight reflecting from our own planet on to the moon and bouncing back at us. Saturn will appear as a steady, creamy point of light. Unlike the stars that will be popping into visibility as the sky darkens, it will not twinkle. Because of their extreme distance, stars appear as point sources of light and so the movement of the atmosphere makes them appear to fluctuate. A planet appears as a tiny disc, even though that extension is indiscernible to our eyes. The various movements of the atmosphere average out across the disc rendering the planet steady. The conjunction also is easily visible from the southern hemisphere.