In May we lose the two brightest lights in the evening sky: Venus and Sirius, the brightest of stars.
Sirius begins the month very low in the southwest and drops out of sight by mid-month. In the last two weeks of May, most of the other bright winter stars also disappear. Venus, a brilliant evening star, plummets through the sky and is gone by month’s end. Near the end of its fall, Mercury pops into the sky; it passes Venus on the 21st, when both are extremely low and in the sun’s afterglow. Venus reappears in the morning sky in July, but then only the early—very early—birds will catch a glimpse of it.
At nightfall Leo, the lion, appears to be leaping downward in the southwest. Look for the bright star Regulus, at the base of a backward question mark of stars called the Sickle; this is the lion’s head. East of Regulus, fairly bright Spica shines from its berth in Virgo, the maiden. Above Spica, radiant Arcturus anchors kite-shaped Bootes, the herdsman.
Jupiter and Saturn rise a couple of hours after midnight on the 1st, appearing earlier every morning. Mars follows them by about two hours. All three planets are well up in the southeast before day starts to break.
As the month goes by, Mars climbs steeply but makes little progress westward. Saturn and brilliant Jupiter, however, hurry westward while making only modest gains in altitude. These giant planets are gradually approaching each other, even as they glide steadily farther from Mars. Above Saturn and Jupiter shines the Summer Triangle of bright stars. Altair, in Aquila, the eagle, is the closest to the planets.
May’s full moon will be another big, bright supermoon. Fullness happens at 5:45 a.m. on Thursday, the 7th. If you watch it rise the night before or after, it will be close to half a day before or past full. If you go out the morning of the 7th, remember to check your local time of moonset. Moonset times range from 5:59 a.m. in Grand Marais to 6:32 a.m. in Pipestone.
The University of Minnesota offers public viewings of the night sky at its Duluth and Twin Cities campuses. For more information and viewing schedules, see:
Duluth, Marshall W. Alworth Planetarium: www.d.umn.edu/planet
Twin Cities, Minnesota Institute for Astrophysics: www.astro.umn.edu/outreach/pubnight
Check out astronomy programs, free telescope events, and planetarium shows at the University of Minnesota's Bell Museum: www.bellmuseum.umn.edu/astronomy
Find U of M astronomers and links to the world of astronomy at http://www.astro.umn.edu