The Moon

May's full Moon
May's Full Moon is known as the Flower Moon
In most areas, flowers are abundant everywhere during this time. Thus, the name of this Moon. Other names include the Corn Planting Moon, or the Milk Moon.

Information excerpt taken from the American Farmer's Almanac.

Mercury is currently invisible behind the Sun, but by the beginning of June it will be visible in the evening sky, very low in the north-west. On the evening of June 1 st it will be just 7° above the north-western horizon half an hour after sunset (i.e. about 20:40 UT). Binoculars will be needed to find it in the strong twilight. This marks the start of quite a favourable evening apparition of Mercury in June.

Venus remains visible in the morning sky just before sunrise, very low in the east.

Mars is still an evening object, now rather faint at magnitude +1.5, fainter than some of the brightest stars in the area. It is currently in central Gemini and is moving swiftly eastwards in the sky, towards Saturn. By early June it will be just 8° west of the ringed planet and the two planets will have a very close conjunction in the summer twilight in mid-June.

Jupiter only passed opposition on May 4 th , so it is visible throughout the night this month, always quite low in the south. The faint star 1.5° below it is a (Alpha) Librae; binoculars reveal this to be a wide double star, consisting of a magnitude 2.7 primary and a magnitude 5.2 companion just to its west.

Saturn is still well-placed in the evening sky, high up in the south-west after dark. It is now starting to move back towards M44 (the Beehive cluster) and by early June will be skirting its southern edge once more.

Comet 73P/Schwassmann-Wachmann 3

A Close Flyby

This month, short-period comet 73P/ Schwassmann-Wachmann 3 makes a close flyby of the Earth, passing just 0.078 Astronomical Units (about 12 million km) at closest approach on May 12 th . This comet is interesting in that it has split up into many fragments. The diagram below, looking due east at 0:00 UT, shows the track of the brightest fragment, known as fragment C, which at time of writing has resisted breaking up. The positions on the diagram are plotted for 0:00 UT on the dates indicated. At time of writing, fragment C is visible in binoculars and small telescopes. It displays a sharp central condensation and a short, fan-like tail. The comet will be well-placed in the evening sky at closest approach and fragment C will come within a few arc minutes of M57, the Ring Nebula, in the early hours of May 8 th . Even at closest approach, it will probably require binoculars to be seen and will also be quite diffuse, since it is so close to the Earth. Unfortunately, the nearly full Moon will interfere at closest approach. After mid-May the comet will quickly disappear in the morning twilight.

International Space Station and lunar phase images reproduced courtesy of Heavens-Above GmbH