No matter when you prefer to observe the stars and planets, this month of May is sure to please you. Any time you choose, a planet will be there for you to train your telescope on, or to simply view with your eyes: Jupiter and Mercury are visible early in the evening, Mars and Saturn are up all night long, and Venus rises before the Sun.
Jupiter and Mercury at twilight
Jupiter is easy to spot above the western horizon at sunset. The giant planet shines brightly among the stars of Gemini, but in case you have any doubt, the lunar crescent will be near Jupiter on the evenings of May 3 & 4.
Nightfall is the ideal time to observe Jupiter with a telescope. Its cloud bands, and four Galilean moons that change position from evening to evening, offer plenty to see. But better hurry: The gas giant will be lost in the glare of twilight when it approaches the Sun in June.
Meanwhile, Mercury offers a good evening apparition in May, though its relatively low position on the west-northwest horizon makes it somewhat trickier to observe than Jupiter. It’s important to optimize conditions if you want to spot the tiny planet: The best period for observing Mercury is around mid-may, when the planet is brightest and when its separation from the Sun is nearly maximal.
Here’s a challenge for tenacious diehards: See if you can observe the thin lunar crescent, to the left of Mercury, an hour after sunset on the evening of May 30. Binoculars, and a clear view of the horizon, will be essential if you wish to succeed. This will be your last chance to observe the furtive planet before it plunges sunward.
Mars and Saturn all night
Mars is in retrograde until May 21, moving westward among the stars of Virgo. The Red Planet appears in the south at nightfall and is still quite bright; look for a gibbous moon next to it on the evenings of May 10 & 11. When the Moon’s glare is absent, you’ll notice the bright star Spica shining near Mars: Its blue-white colour contrasts well with Mars’ reddish hue.
The Red Planet was in opposition on April 8, and though the gap separating Earth from Mars is already beginning to widen, it still remains an interesting object throughout May — especially at nightfall when it appears well above the horizon.
On May 10, Saturn takes it’s turn at opposition: The ringed planet will be visible all night, rising in the southeast at dusk, culminating around mid-night, and disappearing in the southwest at dawn. Saturn is currently among the stars of Libra, which never appears high above the horizon; to observe Saturn with a telescope one should wait for it to approach the meridian. The planet’s magnificent rings are presently inclined in our direction and reveal themselves in all their glory. A nearly-full moon will shine near Saturn on the night of May 13 to 14.
Venus at dawn
Venus has graced the eastern morning sky for several weeks now, where it will remain throughout May. Wondering where east is? Just look for dazzling Venus at dawn, an hour before sunrise! A lunar crescent will appear near Venus on the morning of May 25.
And finally, we cannot let a potentially significant meteor shower slip by without mention. Periodic comet 209P/LINEAR will pass close to Earth this month; on the morning of May 24, around 3:00 A.M., our planet will pass through the cloud of dust and debris left in the comet’s wake. It’s hard to predict how intense the resulting meteor shower will be, but it offers a unique opportunity to observe a brand new shower for the very first time. Here’s to good meteor hunting on the night of May 23 to 24.