2017 April 28
See the Moon and Jupiter get up close on May 7
Although now a few weeks past opposition, Jupiter still remains the dominant object in the night sky. Shining at around magnitude -2.4 and with a disk diameter of 43 arc seconds it is an unmissable beacon in the south. To add to the fun, on May 7 (a Sunday evening) it makes a very close approach to the Moon (or perhaps we should say the Moon makes a very close approach to Jupiter), creating an excellent imaging and observing opportunity. From the UK the event takes place around 22:00 UTC (23:00 BST) with the pair lying due south, 33 degrees above the horizon (from London) and Jupiter just over 1 degree south of the waxing gibbous Moon which will be 3 days from full.
A rich field telescope with a field of view around 2 degrees is ideal and will show the pair nicely or, failing that, a telescope finder scope or firmly mounted binoculars will do. Hand held 10×50 binoculars will easily show the Moon and Jupiter together and larger binoculars, if firmly mounted, will also bring the 4 Galilean satellites clearly into view. Calisto, Europa and Io will be found to the east of Jupiter (Calisto at 7.5 arc minutes – a quarter Moon diameter – the furthest away), with Ganymede lying 6 arc minutes to the west of Jupiter. The Moon and Jupiter will still be only 2 degrees apart when they set at around 03:00UTC. Let’s hope for clear skies!