Jupiter’s opposition in the
Jupiter is at its brightest and best in the constellation of Libra, the Weighing Scales or Balance, this month. Its opposition, when it stands directly opposite the Sun, occurs on the morning of the 9th but it is prominent every night as it transits low across the south from the south- east at nightfall to the south- west before dawn.
Venus, however, outshines it in the western evening sky and both Saturn and the increasingly striking Mars follow Jupiter into the southern morning sky. The Sun climbs another 7° north wards during May as Edinburgh’ s sunrise/ sunset times change from 05: 29/ 20: 52 BST on the 1st to 04: 36/ 21: 45 on the 31st. Because twilight is also lengthening, official darkness in the middle of the night lasts for under one hour by May’s end.
Today’s full moon is followed by last quarter on the 8th, new moon on the 15th, first quarter on the 22nd and full again on the 29th.
Venus stands 20° high in the west at sunset, sinking to set in the north-west by 23:40 tomorrow and one hour later by the 31 st. Brilliant at magnitude - 3.9, it is 6° aboveright of Taurus’ brightest star, Al de bar an, on the 1 stand tracks east- north- east wards between the Bull’ s horns to end May in mid-Gemini, below Castor and Pollux.
The young earth lit Moon make san impressive sight almost 6° below-left of the planet on the evening of the 17 th. Three days later, as Venus joins the region of sky covered by our chart, it passes 1.0°( two Moon-diameters) above-right of the star cluster M 35 whose brightest stars may be glimpsed through binoculars from their distance of some 2,800 light years. Still on the far side of its orbit, Venus approaches from 217 million to 190 million km this month as its almost- full disk swells to 13 arcseconds in diameter.
After dominating our winter nights, Orion ducks below our western horizon as the evening twilight fade sat present. The Plough is overhead and Leo high in the south with its main star Regul us which has a close encounter with the first quarter Moon on the night of 21st/ 22nd.
By our map times, Leo is sinking in the west and Jupiter is easily the most conspicuous object in the south though it stands barely 18° high for Edinburgh. Moving westwards in Libra, it lies to the right of the Moon tonight and close to the Moon again on the 27 th. Its motion takes it from 4° east ( left) of the well- known double star Zubenelgenubi at present to lie just 1.0° north- east of the star on the 31st.
Jupiter is 658 million km away at opposition, shines at magnitude - 2.5 and shows a 45 arcseconds wide disk through a telescope. Its two main darker cloud bands, its northern and southern equatorial belts, straddle a lighter equatorial zone. The famous Great Red Spot is gradually losing its status, however, being less than half as wide as it was a century ago and currently more salmon- pink in hue than red. It sits in a bay at the southern edge of the south equatorial belt and, like the many other Jovian cloud features, is carried smartly across the disk as the planet spins in just under ten hours.