The Night Sky This Month

Northern HemisphereIan Morison tells us what we can see in the night sky above the world's middle line during Month 4 2020.The PlanetsAs April begins, Jupiter rises some three and a half hours before the Sun shining at magnitude -2.1. It then follows Mars and precedes Saturn, just above Mars, into the pre-dawn sky. During the month it brightens to magnitude -2.3 whilst its angular size increases from 37.0 to 40.6 arc seconds. A low south-eastern horizon will be needed and our views of the giant planet and its Galilean moons will be somewhat hindered by the depth of atmosphere through which it will be observed.As April begins, Saturn rises at 05:33 UT, 20 minutes after Jupiter, and by its end at 02:50 UT whilst its magnitude increases slightly from +0.7 to +0.6 whilst its angular size increases from 16.1 to 16.9 arc seconds. Saturn reaches ‘quadrature', 90 degrees in angle from the Sun, on April 21st enhancing the three-dimensionality of its globe and rings. At 21 degrees, the rings are slightly less tilted to