2 May. Look for Venus in the eastern sky about an hour before sunrise. The planet in early May is preposterously bright, shining at about magnitude -4.7, enough to cast a shadow in very dark conditions. At the beginning of the month, in a telescope, you see about 1/4 of the planet’s face lit by the Sun. By the end of the month, you see the planet half lit as it dims slightly to magnitude -4.5. A truly beautiful ‘Morning Star’.
3 May. First-Quarter Moon, 02:47 UT
4 May. The Moon grazes the bright 1st-magnitude star Regulus, the star at the base of the reversed ‘question mark’ that makes up the head and mane of the constellation Leo, the Lion. Observers in the northern hemisphere see the constellation nearly overhead in May. Observers in the southern hemisphere can see the constellation, upside down, well over the northern horizon in the mid-evening hours. If you’re in Australia or New Zealand, look for the Moon to pass in front of the star for a brief time. The exact timing of this occultation is highly dependent on location. You can get timing for the beginning and end of the event for dozens of towns and cities at this link.
5-6 May. The Eta Aquarid meteor shower peaks. This shower occurs as the Earth moves through the path of the famous Comet 1P/Halley (i.e. Halley’s Comet). The shower does not have a sharp peak in time, so go out anytime in the early-morning hours in the first week of May and look up. Because the radiant of the shower lies in the constellation Aquarius, which is well south of the celestial equator, the shower largely favors southern-hemisphere stargazers. If you missed Comet Halley in 1986, here’s a chance to at least see a few crumbs of the comet burn up in the Earth’s upper atmosphere. And if you miss this shower, don’t worry. The Earth passes through the path of the comet again in late October, an event which gives rise to the Orionid meteor shower.
7 May. Look for brilliant Jupiter near the waxing gibbous Moon. The planet is beautifully positioned for inspection in the early evening hours in the constellation Virgo this month. The planet is still retrograding westward in May, and in the first week of the month it lies about 10º north of the bright white star Spica. Watch the motion of the planet westward relative to the star during the month. Jupiter reached opposition in April and now slowly grows fainter and smaller, but it still remains a spectacular sight in a small telescope on a clear night with steady sky. The planet shines at magnitude -2.3, far brighter than any star.
May 7-10. Comet 41P/Tuttle-Giacobini-Kresak passes to the west of the bright star Vega in the constellation Lyra. You can see these stars– and the comet– rising in the northeast in the late-evening hours. You’ll need to hoist a pair of binoculars to see the comet, which shines at 6th-magnitude in early May before fading over the rest of the month. The image below, courtesy of Sky and Telescope, shows the position of the comet. Don’t expect to see much more than a circular smudge.
10 May. Full Moon, 21:42 UT
17 May. Mercury reaches greatest western elongation about 26º west of the Sun. The planet is visible mid-month before sunrise in the eastern sky. Its position on the ecliptic, just a fist’s-width below brilliant Venus, favors southern-hemisphere stargazers this month. In the north, the planet is much lower on the horizon and hard to see without binoculars before the Sun overwhelms its light.
19 May. Last-Quarter Moon, 00:33 UT
22 May. Look for the brilliant planet Venus just 2ºN of the waning crescent Moon in the eastern sky an hour or two before sunrise.
24 May. Look for the waning crescent Moon low over the eastern horizon before dawn. If you can find the Moon, look for Mercury about 1.6º to the north.
25 May. New Moon, 19:44 UTShare This: