Skywatch Line for Friday, September 13, through Sunday, September 15, written by Sam Salem

On Friday, Sun rises at 6:33am and sets at 7:08pm; Moon sets at 12:31am and rises at 4:58pm.

The bright waxing gibbous Moon will hang near Saturn in the east after sunset on Sunday. The waxing gibbous Moon forms a nearly equilateral triangle with Saturn to its left and Fomalhaut to its lower left. The triangle is about 20° on a side.

Saturn, magnitude +0.6 in the constellation of Aquarius, is barely past opposition. Look for it glowing low in the east-southeast as the stars come out. It sits lower right of the Great Square of Pegasus, which is balancing on one corner. The Square’s upper-right edge points diagonally to Saturn almost exactly now, two fists at arm’s length away. Saturn is the bright little dot in the southeast after dark, lower right of the Great Square of Pegasus. Saturn climbs higher through the evening. It shines highest in south around midnight.

Use a telescope on Friday night to observe Saturn’s biggest and brightest moon, 8th-magnitude Titan, glimmering at its maximum elongation about four ring-lengths to Saturn’s east. A 3-inch telescope can pick it up. A 4-inch will begin to show its orange color, caused by its smoggy atmosphere.

Spot Mercury low in the east about 40 or 50 minutes before sunrise. It’s already a bright magnitude –1.0 by Saturday Morning. Mercury passes Regulus, which is fainter at magnitude +1.4. After that, Regulus ascends above Mercury. Bring binoculars.

Venus, magnitude –3.8, is still very low in bright twilight. Starting 20 or 30 minutes after sunset, look for it a little left of due west. It’s getting very slightly higher and brighter week by week. Spica is closing in on Venus from the upper left. They close in to 6° apart On Friday. On Tuesday they’ll pass each other 2½° apart.

Mars and Jupiter, at magnitudes +0.6 and –2.3, respectively, continue pulling apart from each other in the early-morning sky. Watch for bright Jupiter to rise in the east-northeast around midnight. Much fainter Mars rises about an hour later to Jupiter’s lower left. On Saturday morning, the planets are 15° apart.

Jupiter remains in Taurus not far from the Bull’s horn-tip stars, Beta and Zeta Tauri. Mars is now creeping along the trailing foot of the Castor stick-figure in Gemini.

Mars-like Aldebaran shines to Jupiter’s right or upper right by about as far now as Mars shines to Jupiter’s lower left. Mars has become the brighter of these two orange points.

By the start of dawn each morning, all three are very high in the southeast.

Six planets (Mercury, Mars, Jupiter, Saturn, Uranus, and Neptune) appear together in Earth’s predawn sky now. They’re all clumped together in a single quadrant of our solar system. Venus is behind the Sun from the other planets. That’s why Venus is in our evening sky now and so not part of the 6-planet parade before dawn.

This is Dudley Observatory’s Skywatch Line for This is Dudley Observatory’s Skywatch Line for Friday, September 13, through Sunday, September 15, written by Sam Salem.

On Friday, Sun rises at 6:33am and sets at 7:08pm; Moon sets at 12:31am and rises at 4:58pm.

The bright waxing gibbous Moon will hang near Saturn in the east after sunset on Sunday. The waxing gibbous Moon forms a nearly equilateral triangle with Saturn to its left and Fomalhaut to its lower left. The triangle is about 20° on a side.

Saturn, magnitude +0.6 in the constellation of Aquarius, is barely past opposition. Look for it glowing low in the east-southeast as the stars come out. It sits lower right of the Great Square of Pegasus, which is balancing on one corner. The Square’s upper-right edge points diagonally to Saturn almost exactly now, two fists at arm’s length away. Saturn is the bright little dot in the southeast after dark, lower right of the Great Square of Pegasus. Saturn climbs higher through the evening. It shines highest in south around midnight.

Use a telescope on Friday night to observe Saturn’s biggest and brightest moon, 8th-magnitude Titan, glimmering at its maximum elongation about four ring-lengths to Saturn’s east. A 3-inch telescope can pick it up. A 4-inch will begin to show its orange color, caused by its smoggy atmosphere.

Spot Mercury low in the east about 40 or 50 minutes before sunrise. It’s already a bright magnitude –1.0 by Saturday Morning. Mercury passes Regulus, which is fainter at magnitude +1.4. After that, Regulus ascends above Mercury. Bring binoculars.

Venus, magnitude –3.8, is still very low in bright twilight. Starting 20 or 30 minutes after sunset, look for it a little left of due west. It’s getting very slightly higher and brighter week by week. Spica is closing in on Venus from the upper left. They close in to 6° apart On Friday. On Tuesday they’ll pass each other 2½° apart.

Mars and Jupiter, at magnitudes +0.6 and –2.3, respectively, continue pulling apart from each other in the early-morning sky. Watch for bright Jupiter to rise in the east-northeast around midnight. Much fainter Mars rises about an hour later to Jupiter’s lower left. On Saturday morning, the planets are 15° apart.

Jupiter remains in Taurus not far from the Bull’s horn-tip stars, Beta and Zeta Tauri. Mars is now creeping along the trailing foot of the Castor stick-figure in Gemini.

Mars-like Aldebaran shines to Jupiter’s right or upper right by about as far now as Mars shines to Jupiter’s lower left. Mars has become the brighter of these two orange points.

By the start of dawn each morning, all three are very high in the southeast.

Six planets (Mercury, Mars, Jupiter, Saturn, Uranus, and Neptune) appear together in Earth’s predawn sky now. They’re all clumped together in a single quadrant of our solar system. Venus is behind the Sun from the other planets. That’s why Venus is in our evening sky now and so not part of the 6-planet parade before dawn..

On Friday, Sun rises at 6:33am and sets at 7:08pm; Moon sets at 12:31am and rises at 4:58pm.

The bright waxing gibbous Moon will hang near Saturn in the east after sunset on Sunday. The waxing gibbous Moon forms a nearly equilateral triangle with Saturn to its left and Fomalhaut to its lower left. The triangle is about 20° on a side.

Saturn, magnitude +0.6 in the constellation of Aquarius, is barely past opposition. Look for it glowing low in the east-southeast as the stars come out. It sits lower right of the Great Square of Pegasus, which is balancing on one corner. The Square’s upper-right edge points diagonally to Saturn almost exactly now, two fists at arm’s length away. Saturn is the bright little dot in the southeast after dark, lower right of the Great Square of Pegasus. Saturn climbs higher through the evening. It shines highest in south around midnight.

Use a telescope on Friday night to observe Saturn’s biggest and brightest moon, 8th-magnitude Titan, glimmering at its maximum elongation about four ring-lengths to Saturn’s east. A 3-inch telescope can pick it up. A 4-inch will begin to show its orange color, caused by its smoggy atmosphere.

Spot Mercury low in the east about 40 or 50 minutes before sunrise. It’s already a bright magnitude –1.0 by Saturday Morning. Mercury passes Regulus, which is fainter at magnitude +1.4. After that, Regulus ascends above Mercury. Bring binoculars.

Venus, magnitude –3.8, is still very low in bright twilight. Starting 20 or 30 minutes after sunset, look for it a little left of due west. It’s getting very slightly higher and brighter week by week. Spica is closing in on Venus from the upper left. They close in to 6° apart On Friday. On Tuesday they’ll pass each other 2½° apart.

Mars and Jupiter, at magnitudes +0.6 and –2.3, respectively, continue pulling apart from each other in the early-morning sky. Watch for bright Jupiter to rise in the east-northeast around midnight. Much fainter Mars rises about an hour later to Jupiter’s lower left. On Saturday morning, the planets are 15° apart.

Jupiter remains in Taurus not far from the Bull’s horn-tip stars, Beta and Zeta Tauri. Mars is now creeping along the trailing foot of the Castor stick-figure in Gemini.

Mars-like Aldebaran shines to Jupiter’s right or upper right by about as far now as Mars shines to Jupiter’s lower left. Mars has become the brighter of these two orange points.

By the start of dawn each morning, all three are very high in the southeast.

Six planets (Mercury, Mars, Jupiter, Saturn, Uranus, and Neptune) appear together in Earth’s predawn sky now. They’re all clumped together in a single quadrant of our solar system. Venus is behind the Sun from the other planets. That’s why Venus is in our evening sky now and so not part of the 6-planet parade before dawn.