Title: July Skywatch Highlights
Location: Hawaiian Islands
Date / Time: July 2011
Comments: Behold our spectacular summer skies! Glorious bands of Milky Way stars illuminate our dark Hawaiian sky with a rich, "milky" haze. The stars & constellations of the Summer Triangle (Navigator's Triangle) grace the northern sky (Altair, in Aquila the Eagle; Vega in Lyra, the Harp; & Deneb in Cygnus the Swan), while Scorpius, the giant Scorpion, & Sagittarius, the Archer, display boldly toward the south. July evenings provide opportunities for naked-eye viewing of the planet MERCURY. Shining at magnitude minus ? 0.4 (early in the month), the tiny innermost planet "pops" out of the twilight glow just as the sky starts to darken. Look for Mercury in the west, around 8pm, about 10 degrees above the western horizon. As Mercury is the closest planet to the Sun, it always appears close to Sun. We only see it rising just before the Sun in the morning, or setting just after the Sun in the evening. Mercury reaches greatest elongation July 19/20, when it lies 27 degrees east of the Sun. SATURN shines in the western evening sky throughout July. Saturn lies in the constellation Virgo, & appears as a bright dot, 15-degrees to the right (NW) of Spica, Virgo's brightest star. Saturn shines at magnitude 0.9 which makes it slightly brighter than Spica, and a bit fainter than Arcturus (Hokule'a), which appears NE of the Ringed Planet. Notice the color contrast between golden Saturn, blue-white Spica, & yellow-orange Arcturus. Saturn appears close to (almost on top of) Virgo's second-brightest star, Porrima (Gamma Virginis). Saturn's rings now tilt at 8-degrees from our line of sight, affording wonderful telescopic views of their various features all month. Dazzling JUPITER certainly lives up to it's nickname this month: The King of Planets. The gas giant rises in the east at 2am in early July, & at midnight by the end of the month; & at magnitude minus -2.4, it appears as the brightest object in our morning sky (except for the Moon). With a small telescope or good binoculars, you can view Jupiter's 4 bright Galilean moons in their ever-changing configurations. Galileo first saw them nearly 400 years ago with a 1.5-inch telescope of lower quality than any available today. Also in the morning sky, look for MARS , rising in the east around 3:30am in early July, & at around 3am at month's end. On the morning of July 6th, Mars appears in Taurus, 5-degrees north of Aldebaran, the Bull's brightest star. The Red Planet is a near color match to Aldebaran, the red giant star which represents the "eye" of the Bull. Shining at magnitude 1.4, Mars appears slightly fainter than the star. Watch Mars trek across Taurus during July. It passes between the horns of the Bull on July 26th and, a day later, appears near a slim crescent Moon for a lovely morning scene. VENUS appears low in the east-northeast before dawn in early July. It shines brilliantly at magnitude minus -3.8, which is the only reason it shows up in the bright twilight. After the first week of July, Venus will be lost in the Sun's glow. It will reappear in the evening sky in late September. For a July Hawaiian sky map, visit Bishop Museum Planetarium www.bishopmuseum.org/planetarium (bishopmuseum.org).

Maintained by Roz Reiner - Kauai, Hawaii

 

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