This is the Dudley Observatory Skywatch Line for Wednesday, June 12th, and Thursday, June 13th, written by Louis Suarato.
The 77% illuminated, waxing gibbous Moon rises at 3:37 p.m. Wednesday. At 9:30 p.m., the Moon will be 40 degrees above the southern horizon, while Jupiter, just 2 days past opposition, will be 10 degrees above the southeastern horizon. Jupiter’s Galilean moon events include Io emerging from behind the planet at 9:44 p.m. Wednesday, and Europa passing behind Jupiter beginning at 3:12 a.m., Thursday. Also at 9:30 p.m., look for Mars and Mercury 8 degrees above the west-northwestern horizon separated by 3 degrees. You may require binoculars to see both planets.. Mercury will be brighter, and to the right of Mars. Saturn rises at 10:15 p.m. Wednesday in the constellation Sagittarius.
Twilight helps you determine the Moon is in Virgo. To the right of the Moon is Virgo’s brightest star, Spica. Virgo is the second largest constellation and is rich in galaxies, including those that are part of the Virgo Cluster, which consists of 1,200 to 2,000 galaxies, such as:; Messier 49 (elliptical), Messier 58 (spiral), Messier 59 (elliptical), Messier 60 (elliptical), Messier 61 (spiral), Messier 84 (lenticular), Messier 86 (lenticular), Messier 87 (elliptical and a famous radio source), Messier 89 (elliptical) and Messier 90 (spiral). A galaxy that is not part of the cluster is the Sombrero Galaxy (M104), an unusual spiral galaxy. It is located about 10° due west of Spica.
Spica is the fifteenth brightest star in the sky. One of the reasons is its close proximity to Earth. Spica is only 250 light-years away. Spica is a close binary system, whose members are too close to be split telescopically. The two stars orbit each other once every 4.01 days. Use Spica to locate the constellation Virgo by beginning at the Big Dipper and following the arc of its handle to Arcturus, then speeding down to Spica.