Observers in the UK with a view low to the west about 1am BST on Saturday, 11 May 2019 (some 1½ hours before moonset for the centre of the British Isles) can see the 6-day-old waxing crescent Moon just 1½ degrees from the prominent open cluster Messier 44, otherwise known as Praesepe, or the Beehive Cluster. After the Moon has set in Western Europe its orbital motion brings it even closer to M44, actually occulting some of the cluster’s southernmost stars as seen from North America’s Eastern Seaboard just before local midnight on on 10 May. AN graphic by Ade Ashford.The Moon was new on 4 May, so the young lunar crescent soon makes its presence known at dusk, particularly in Northern Hemisphere skies where the ecliptic makes a steeper angle to the western horizon. If you own a pair of binoculars, you may wish to take a look at the Moon on the night of 10-11 May since it lies in the constellation of Cancer, the Crab, in the same field of view as the beautiful open star cluster known as Praesepe, the Beehive Cluster, or more prosaically as Messier 44.
For observers in Western Europe and the UK, the Moon’s orbital motion doesn’t bring it close to the Beehive Cluster until the calendar clicks onto 11 May, by which time the pair are well on their way to setting in the western sky. For anyone in the British Isles the last views will be around 1am BST on Saturday 11 May when the 6-day-old Moon lies just 1½ degrees from the heart of Praesepe and the duo will be just 10 degrees – about the span of a fist at arm’s length – above the west-northwest horizon.
This conjunction of Praesepe and the Moon favours the Eastern Seaboard of North America where, as night falls on Friday, 10 May the lunar crescent is poised to pass in front of the western edge of the star cluster. If you have a telescope, use your lowest magnification eyepiece and watch from 10pm local time until midnight as the Moon glides over the southern edge of the Beehive Cluster, occulting (passing in front of) a number of its stars.
UK observers with a clear sky an hour before sunrise on Friday 28 October should look very low in the east-southeast to see the slim crescent of the 27-day-old Moon less than four lunar diameters away from largest planet Jupiter. The Moon and Jupiter are also joined by third-magnitude double star gamma (γ) Virginis, commonly known as Porrima.
If you would like to view ringed planet Saturn at its best but are unsure which ‘star’ you should point your telescope at, no problem — the Moon makes a convenient guide as it brushes close by late into the evening of Monday, June 1st.
Jupiter is now less than a month from opposition (7 April), so it’s very much open season for the Solar System’s largest planet. If you’re unsure where to find it, the rising 17-day-old waning gibbous Moon passes just two degrees from Jupiter on the UK evening of 14 March. Virgo’s brightest star, first-magnitude Spica, makes it a great binocular triumvirate.
