Sky Lights ~ Leo
July 22 - August 23, 2011
Planets ... those seen with the unaided eye
Jupiter is getting brighter and spending more time in a dark sky. The brilliant planet at magnitude -2.5 dazzles night owls and early birds. It rises in the east at 12:30am in the beginning of Leo and at 11:00pm by its end. 7/23 the Last Quarter Moon lies above Jupiter and 7/24 the waning Crescent Moon lies to the left (north) of the planet. 7/23-24 3am Map ~ 7/23 Dawn Map ~ 7/24 After Midnight Map/Text 8/1 Jupiter is at west quadrature. The mornings of 8/19, 20, 21 the waning Gibbous Moon dances with Jupiter. 8/19 After 12am Map ~ 8/20 2am Map ~ 8/21 After 12am Map/Text The launch window for Juno: NASA's Jupiter Mission opens 8/5/11. Esoteric Jupiter
Mars gradually rises higher above the eastern horizon, though you may still need binoculars to spot the planet in a twilit sky. Each morning our Red Planet at magnitude 1.4 can be viewed in a dark sky. It rises about 3:00am in the beginning of Leo and at 2:45am by its end. At the end of July Mars lies between the horn tips of Taurus the Bull. 7/26 the waning Crescent Moon lies near the Bull's eye star, reddish Aldebaran, and 7/27 near our Red Planet at the Bull's horn tips. During Leo be sure to compare the ruddy hue of Mars to the color of slightly brighter Aldebaran. 7/26 Dawn Map/Text ~ 7/27 5am Map ~ 7/27 Before Dawn Map Look for Jupiter southwest of the Moon and Mars on these days. Use this 7/26 5am Sky Chart for orientation. By 8/1 Mars moves toward the foot of the Gemini Twin, Castor. The planet far outshines this foot star. By 8/18 Mars lies near the knee star of Castor, Mebsuta. View the stars of the Gemini Constellation. Current Missions to Mars ~ Esoteric Mars
Venus is hidden in the morning Sun's glowing embrace. The planet is in superior conjunction 8/16 when it begins to switch to the evening sky. Venus reappears very low on the western horizon September 30 and is easier to view as it rises higher in October. Europe's Mission to Venus ~ Esoteric Venus
Mercury is difficult to see just after sunset on the western horizon. July 19/20 the planet dimmed to magnitude 0.3 and achieved greatest elongation, 27º from the Sun's glaring light. During Leo Mercury's 8 degree altitude, 30 minutes after sunset, decreases until the planet reaches inferior conjunction 8/16. See this 8/1 Sunset Map/Text ~ Another View Note: 8/16 while Mercury is at inferior conjunction, Venus is at superior conjunction; both planets are in exact conjunction with the Sun and each other on this day. Mercury begins its retrograde cycle (8/2-25) very near Regulus; see * for more. The planet reappears in the morning sky at the end of August. 8/27 the last vestige of the waning Crescent Moon appears near Mercury; Mars lies above. 8/27 Dawn Map/Text ~ 8/27 6am Map MESSENGER is the first spacecraft to orbit Mercury. Esoteric Mercury
Saturn at magnitude 0.9 is located in the west-southwest at nightfall. The Lord of the Rings moves toward the western horizon until it sets, at 11:30pm in the beginning of Leo and around 10:00pm by its end. Saturn is sinking in the west. 8/1 the planet is about 20º (degrees) above the sunset horizon as the sky darkens and by 8/31 only 5º. The planet's yellowish glow is eye-catching about 15º (degrees) to the right of bluish Spica. Saturn is a tad brighter than Spica. Look for the large northern-tipped isosceles triangle formed by Saturn and Spica at the base and golden Arcturus at the apex. Use the Big Dipper to locate Saturn (see Arcturus below for details). 8/2-4 the waxing Crescent Moon dances near Saturn. 8/2 Nightfall Map ~ 8/3 8:45pm Map ~ 8/4 Nightfall Map/Text Though Saturn's distance from the Earth is increasing, Saturn's rings are opening, revealing more and more of their northern face and reflecting more light. This lessens the planet's dimming process as it journeys farther from Earth. The planet's ring tilt is 9º in August and widens to 15º in December. Generate images of Saturn's ring tilt as seen from Earth with the Solar System Simulator. With a 6- or 8-inch telescope you just may be able to see Saturn's 5 brightest moons. NASA's Cassini Mission to Saturn ~ Saturn's Super Storm ~ Esoteric Saturn
Arcturus is the bright golden star seen in the west. Use the handle of the Big Dipper to arc down to Arcturus from there, spike down to blue-white Spica in the south. Helpful Image From nightfall until Saturn sets (11:30pm in the beginning of Leo and 10:00pm by its end) look southwest for bluish Spica about 15º (degrees) to the left of yellowish Saturn, both below bright golden Arcturus. These 3 colorful celestial bodies form a large isosceles triangle with Arcturus as the apex, tipped toward the north. The westward movement of Arcturus and the Big Dipper can be observed in the beginning of Leo until 2:00am and by its end until 12:45am. Big Dipper Navigation Notice the seasonal position of the Big Dipper's bowl. Learn more about Arcturus.
Scorpius the cosmic scorpion, a sprawling j-shaped constellation, is seen in the south at sunset. Antares is the red heart star of Scorpius. With binoculars on a moonless night can you find the Scorpion's missing claws (now the constellation Libra), its two stinger stars sometimes called cat's eyes or how about the star clusters M6 and M7 above the Scorpion's stinger? These Maps/Text from 2008 are helpful. Throughout the year you can Track Bunny's Footprints in Scorpius! 8/6 the First Quarter Moon passes east of the Scorpion's "missing claws." 8/6 Evening Map/Text 8/7-8 the waxing Gibbous Moon first lies near Antares the heart of Scorpius, then near the stinger of Scorpius. 8/7 Map/Text ~ 8/8 Map/Text Learn more about the Zodiacal Deity.
The Summer Triangle a stellar right triangle is high in the northeast at sunset. Vega is the brightest star and western point; Deneb the dimmest star and eastern point, Altair is the southern point. Hercules the Strong Man lies about a third of the way from bright white Vega to golden Arcturus in the northwest. Look for his four star wedge-shaped torso. Summer Stars
The Milky Way appears like a faint cloud extending from Scorpius on the southern horizon, to the Summer Triangle high overhead, and onward toward Cassiopeia (M or W shaped) on the northern horizon. Star Map Learn more about the Milky Way.