This is the Dudley Observatory Skywatch Line for Wednesday, August 26th, and Thursday, August 27th, written by Louis Suarato.
The 61% illuminated, waxing gibbous Moon rises at 3:02 p.m. Wednesday. The Moon sets at 28 minutes past midnight. At twilight, the Moon will be on the one side of the constellation Sagittarius, while Jupiter and Saturn are on the other side. Thursday night, the Moon moves into Sagittarius, and closer to the two gas giants. Mars rises in Pisces at 9:51 Wednesday night. The red planet is now 90% illuminated, and will continue to brighten as it approaches opposition on October 13th. Venus rises in Gemini at 2:33 a.m., Thursday and is 58% illuminated.
The International Space Station will make a bright -3.1 magnitude pass by Mars and Venus Thursday morning. The ISS will appear in mid-sky in the constellation Cetus at 4:49 a.m. about 38 degrees above the south-southwestern horizon. The space station will sail under Mars before heading toward Orion. The ISS flies below Taurus’ brightest star, Aldebaran, before crossing through Orion and heading toward Gemini, where it will intersect Pollux and Venus before heading toward the east-northeastern horizon.
Looking for something bright to focus on while the gibbous Moon is in the sky? Set your sights within the constellation Hercules for a bright globular cluster. M13, the Great Globular Cluster of about 300,000 stars can be found on the asterism known as the Keystone. The stars within this cluster span 145 light-years and are 100 light-years away. Discovered by Edmond Halley in 1714, the Great Globular Cluster contains stars almost as old as the universe, between 12 and 13 billion years old. For those with goto technology on your telescopes, the location of M13 is Right Ascension: 16h 41.7m Declination: 36 degrees 28’ north. For those without goto technology, look for Hercules between the constellations Lyra and Bootes, about a third of the way between their brightest stars, Vega and Arcturus. Once you’ve identified the Keystone, Look between the line formed by the two stars on the widest part of the trapezoid, Eta Heculis and Zeta Herculis, on the Arcturus side of the Keystone. M13 is located closer to Eta Herculis.