The sky this week for August 3 to August 5
All eyes are on Mars this week. The Red Planet has finally reached its long-awaited opposition, and will remain a spectacular sight for naked-eye and telescopic observers alike.
By Richard Talcott
Friday, August 3
Although Jupiter reached opposition and peak visibility nearly three months ago, it remains a stunning sight from evening twilight until it sets around midnight local daylight time. Jupiter shines at magnitude –2.1 and dominates the southwestern sky as night falls. The gas giant resides among the background stars of Libra the Scales, 1.3° northwest of Zubenelgenubi (Alpha [α] Librae). If you view the planet through a telescope tonight, its disk spans 38″ and displays spectacular cloud-top detail. You’ll also see the gas giant’s four brightest moons. These are the biggest of Jupiter’s entourage of 79 satellites; this number grew by a dozen last week when astronomers announced their discovery of several more far-flung moons.
Saturday, August 4
Last Quarter Moon occurs at 2:18 p.m. EDT. It doesn’t rise until 12.30 a.m. local daylight time tomorrow, however, by which time North American observers might notice that its phase has diminished to 44 percent lit. Earth’s only natural satellite spends the morning near the border between the constellations Aries the Ram and Taurus the Bull.
Sunday, August 5
Saturn reached its peak a little more than a month ago, when it appeared opposite the Sun in the sky, and our view of the ringed planet remains magnificent. It appears against the backdrop of northern Sagittarius, a region that climbs highest in the south between 10 and 11 p.m. local daylight time. Saturn continues to shine brightly, too, at magnitude 0.2. When viewed through binoculars, you’ll find the Trifid Nebula (M20) 2.5° west of the planet, with the even brighter Lagoon Nebula (M8) 1° south of the Trifid. But the best views of Saturn come through a telescope, which reveals the planet’s 18″-diameter disk surrounded by a dramatic ring system that spans 41″ and tilts 26° to our line of sight.