This is the Dudley Observatory Skywatch Line for Wednesday, July 3rd, and Thursday, July 4th, written by Louis Suarato.
Wednesday night, the 2% illuminated, waxing crescent Moon sets at 9:35 p.m., about 15 minutes before, and a few degrees below Mars and Mercury. Binoculars will help you see this conjunction of two planets and a thin crescent Moon low above the west-northwestern horizon about an hour after sunset. At the time of moonset, you’ll find Jupiter 20 degrees above the south-southeastern horizon. Saturn will be rising in the southeast. Jupiter’s closest moon, Io, travels behind the planet, beginning at 42 minutes past midnight, Thursday. Io will emerge at 3:27 a.m. from behind the gas giant.
NASA has recently announced a new Dragonfly Drone Mission will explore Saturn’s largest Moon, Titan. Saturn, which is larger than the planet Mercury, is the only Moon with a substantial atmosphere, and the Dragonfly drone will land periodically to take measurements and collect other data. Titan is the only world, other than Earth, to have standing liquid on its surface. Unlike Earth, whose liquid is water, Titan’s surface contains seas of liquid methane. The mission is scheduled to launch Dragonfly in 2026, and reach Titan in 2034.
Celebrate this 4th of July by observing a deep sky object known as the Fireworks Galaxy. Discovered by William Herschel in 1798, the Fireworks Galaxy, also known as NGC 6946, is about 25.2 million light-years away. Having a diameter of 40,000 light-years, this face-on spiral galaxy is about a third of the size of the Milky Way, and contains about half as many stars. NGC 6946 is categorized as a starburst galaxy because of its significant star formation. The Fireworks Galaxy is the home of the Red Ellipse, a very large supernova remnant along one of its northern spiral arms. Another feature of this galaxy is known as Hodges Complex, a smaller, interacting galaxy. Look for the Fireworks Galaxy at the upper left, and north of the star, Deneb, the tail of Cygnus.