Observers in the UK looking at the rising full Moon low in the southeast around 11pm BST on Monday, 30 April will also see conspicuous planet Jupiter close by. The Moon’s separation from the solar system’s largest planet is just 3½ degrees at this time, the pair fitting comfortably within the field of view of typical binoculars. AN graphic by Ade Ashford.Observers in Western Europe watching the full Moon rise in the southeast late into the evening of Monday, 30 April cannot fail to notice the conspicuous ‘star’ a short distance to its right. This is Jupiter, the solar system’s largest planet, which is rapidly approaching opposition and its closest approach to our planet for the year.
Jupiter is nearest to Earth at 11:55 UT on 10 May 2018 when the separation of our two worlds is almost 4.4 astronomical units, or 658 million kilometres (409 million miles). Jupiter is around 660 million kilometres distant on the UK evening of 30 April, but the planet’s mighty 140,000-kilometre-wide globe — almost 11 times the diameter of Earth — requires a telescope magnifying just 41× to enlarge it to the same size as the adjacent Moon appears to the unaided eye.A simulation of a high-power erect-image telescope view of Jupiter and its four Galilean moons Io, Europa, Ganymede and Callisto at 22:00 UT (11pm BST) on 30 April 2018. Observers with Newtonian/Dobsonian telescopes should rotate the image through 180° to match their eyepiece view, while users of refractors and catadioptrics (Schmidt- and Maksutov-Cassegrains) with a star diagonal need to mirror this graphic left-right to replicate their ocular orientation. AN graphic by Ade Ashford.The planet’s rapid rotation will have carried the Great Red Spot out of view by the time observers in the British Isles get a chance to observe Jupiter on the last night of April, but the four large Galilean moons Io, Europa, Ganymede and Callisto will be on show. Their configuration changes rapidly from night to night due to the moons’ orbital motion, but the graphic above will help you identify which is which on the night in question.
Predictions of Jovian phenomena for a given date, time and location are always available through our interactive online Almanac.
Astronomy Now Online brings you a powerful interactive global Almanac and UK-based all-sky star maps — the first of a new suite of tools to help plan your observing sessions and travel.
As avid skywatchers will already know, all of the bright naked-eye planets are currently visible in the pre-dawn sky — the first time in eleven years that such an alignment has occurred. At 6am GMT on Monday, 1 February, the last quarter Moon in the constellation Libra lies just 2½ degrees from magnitude +0.8 planet Mars low in the south for UK observers.
