Last month Mars reached opposition – the position in our skies opposite the Sun – and the place where planets with orbits bigger than Earth’s orbit are seen at their best and brightest. For Mars this was its first opposition in over 2 years. In May Mars is still a prominent object, though a bit dimmer than it was in April, in the south-southeastern sky among the stars of Virgo.
This month brings Saturn into opposition – on May 10th – opposite the Sun in our sky for the first time since last year. Saturn therefore, will rise in the east among the stars of Libra and reach its highest point in the southern sky around midnight to 1 am. This year because Saturn’s rings tilt 22 degrees to our line of sight, greater detail may be seen through telescopes. Additional light, meaning additional brightness will be achieved even though Saturn is very distant from Earth. The planet and its rings will reflect enough light to make it appear at + 0.1 magnitude; its best in over 2 years.
The Moon will track close to some of the planets in the month of May setting up some nice conjunctions; which are easy to see with the unaided eye. The waxing gibbous Moon may be seen just below Mars on May 11th, and the May 14th Full Moon will be seen less than a degree below Saturn.
Mercury will join the planet parade this month too, appearing just 3 degrees below the Pleiades star cluster, low in the west sky just after sunset around May 10th. By May 13th, Mercury will have moved to appear just above Aldebaran, Taurus’s brightest star; still low in the west after sunset. On May 24th, Mercury reaches its greatest angle away from the Sun (elongation) and will set some 2 hours after the Sun. Meanwhile, Jupiter still dazzles in the west sky after dark until it sets around midnight, at magnitude –2.0. And Venus remains a “morning” star , rising about 90 minutes before the Sun; so it will be low in the southeast sky. However at magnitude –4.0 it is prominent until 30 minutes before sunup.
A new meteor shower may appear before dawn on May 24th. astronomers are predicting that Earth will pass through a debris field left behind from Comet 209PLINEAR which went through the inner solar system just a few years ago. Up to 100 meteors per hour may show up from this encounter with the peak area and direction to look being nearly due north between Ursa Major(Big Dipper) and Camelopardalis (straight down to the horizon from the Big Dipper, now in spring, riding high up in the North.
Full Moon is May 14th; Last Quarter May 21st; New Moon on the 28th. First Quarter is early – on May 6th.