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 2º north 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 UT
Other notable highlights include:
Morning Planets: Venus, Saturn, Uranus and Neptune
Evening Planets: Mars, Jupiter