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This is the Griffith Observatory Sky Report through July 8, 2015. Here’s what’s happening in the skies of southern California.
The brightest planet, Venus, and the second brightest planet, Jupiter, continue to appear close together in the west after sunset. Night after night, the separation between the two planets grows. On the 1st, their separation is just over ½ degree, a little wider than the area of sky covered by the full moon. Both planets will still be close enough to each other be seen together through small telescopes at low power. By the 8th, they will be 3½ degrees apart, but should both easily fit into the same binocular field of view. Venus and Jupiter set together in the west-northwest at 10:35 p.m. on the 1st and 10:15 p.m. on the 8th.
Golden-hued planet Saturn is in the southern sky as darkness falls, and shines brightly from the constellation Libra the Scales. Saturn sets in the west-southwest at about 3:00 a.m. This is an ideal time for an early evening view of the planet and its beautiful system of rings through a telescope, and is currently a featured object through the public telescopes at Griffith Observatory.
The moon is full on Wednesday evening, July 1. This full moon, the first of two this month, has the traditional Algonquin name the Full Buck Moon. The moon is a waning gibbous on the following nights until Wednesday the 8th, when it reaches last quarter phase. The time of moonrise changes from 7:48 p.m. on the 1st to 12:14 a.m. on the 8th.
The planet Mercury is visible more than 5 degrees (half as high as your clenched fist appears when held at arm’s length) above the east-northeast horizon, starting at 5:46 a.m., about 30 minutes before sunrise. Mercury looks like a bright star to the unaided eye. Through a telescope, Mercury displays a gibbous phase.
Earth is farthest from the sun, at the point in its orbit called the aphelion, on July 6 at 12:37 p.m., PDT. The center of Earth and sun are then 94,506,346 miles from each other, 1,555,054 miles farther than the average distance, and 3,105,158 miles farther than we were on January 4, when we were at perihelion, the closest point of our orbit to the sun. The tilt of earth’s axis, not the orbital distance from the sun, is responsible for the seasons.
Free views of the sun during the day and of the moon, planets, and other celestial objects at night are available to the public in clear weather through Griffith Observatory’s telescopes from Tuesday through Sunday before 9:30 p.m. Check our website for the schedule. Please note that congested traffic conditions are expected on Saturday, July 4. Griffith Observatory is too far away from firework displays to provide good views of any of them. The next public star party on the grounds of Griffith Observatory, hosted by the Los Angeles Astronomical Society, the Sidewalk Astronomers, and the Planetary Society, will take place on Saturday, July 25.
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From Griffith Observatory, I’m Anthony Cook and I can be reached at griffithobserver@gmail.com