A nice grouping of three planets will grace the pre-dawn sky this week. Mars, Jupiter and Saturn will all rise in the south-east about an hour before the sun. The chart shows the view looking in that direction at 05:15 GMT on 18 March. On that morning, the planets will be joined by a waning crescent moon. Just 32% of the moon’s near-side will be illuminated at that time. If you can find a horizon low enough, the planets will be unmistakeable, partly because they are clustered together and partly because there are no bright stars close to them. The only conspicuous stars in that broad region of the sky will be Altair in Aquila, the Eagle, and Antares in Scorpius, the scorpion. Observers in the southern hemisphere have a much easier time for seeing this conjunction. By the early hours of the morning, the planets will be nicely placed in the eastern sky. They will be easily visible in complete darkness.
