Skywatch Line for Friday, July 18, through Sunday, July 20, written by Sam Salem
This is Dudley Observatory’s Skywatch Line for Friday, July 18, through Sunday, July 20, written by Sam Salem.
On Friday, Sun rises at 5:33am and sets at 8:29pm; Moon sets at 2:23pm.
The Moon will reach perigee, its closest point to us in its elliptical orbit around Earth, on Sunday, when it’s 228,690 miles away.
On Saturday before sunrise, the waning crescent Moon will be high in the sky with the lit portion of the Moon pointing toward Venus. The bright star Aldebaran will be near Venus. The Pleiades star cluster will lie between the Moon and Venus.
Before sunrise on Sunday, the waning crescent Moon will float close to, and in front of, the Pleiades star cluster. Both will be near Venus, Aldebaran and the Hyades star cluster.
In the early-morning hours of Sunday, the bright limb of the waning crescent Moon will occult a few of the Pleiades stars for various parts of North America. They’ll later reappear from behind the Moon’s dark limb, where the events will be much easier to observe.
Venus, at magnitude –4.1, rises above the east-northeast horizon a half hour or more before dawn. In a telescope Venus’s shrinking globe has become gibbous, 65% sunlit.
Mars, magnitude 1.5 in the constellation of Leo the Lion, lies low in the west in late twilight. It sets soon after dark. Above Mars by a little more than a fist at arm’s length sits Denebola, Leo’s tail-tip.
Jupiter, magnitude –1.9, emerges very low in the glow of sunrise. Find it almost three fists lower left of Venus.
Saturn, magnitude +0.9 in the constellation of Pisces, rises around midnight daylight. Try watching Saturn using a telescope just before dawn when it’s near its highest in the south.
Neptune lies just 1° above Saturn before dawn begins. Use the finder chart for Neptune with respect to Saturn/
Sagittarius Teapot sits low in the south-southeast after nightfall. The Teapot is about as big as your fist at arm’s length. Find Scorpius lower right of the Sagittarius’ Teapot’s spout, by a fist at arm’s length or less. The rich area around the tail of Scorpius is at its highest in the south right after night is fully dark. Spot the two stars especially close together in the tail. These are Shaula and Lesath, Lambda and Upsilon Scorpii, also known as the Cat’s Eyes. They’re unequal and leaning at an angle as if the cat is tilting his head to the right. Between the Cat’s Eyes and the Teapot’s spout are the open star clusters M7 and M6. M7 is the bigger and brighter one, M6 is more subdued.