Sky Report
The Griffith Observatory Sky Report
Anthony Cook
Astronomical Observer
This is the Griffith Observatory Sky Report for the week ending Wednesday, July 30. Here is what’s happening in the skies of Southern California:
Venus is visible low in the west-northwest at about 8:15 p.m. It is then 5 degrees high, and sets 30 minutes later.
Through a telescope, Venus only shows a tiny, fully lit disk. The planet slowly appears to grow and its phase changes to crescent over the next 6 months as its rapid orbital motion (compared to ours) moves it from the far side of the sun to between our planet and the sun, allowing less and less of its daytime half to be seen.
As Venus becomes visible, so does Jupiter on the opposite side of the sky. Look about 18 degrees up from the southeast horizon to find the bright yellow planet. Jupiter, in Sagittarius the Archer, is highest, 34 degrees above the due south point, at about 11:40 p.m. and sets five hours later.
At 9:00 p.m., Saturn is due west, less than 10 degrees above the horizon. Fainter Mars is less than 10 degrees to the upper left of Saturn. Saturn sets at about 8:40, 20 minutes before Mars.
The phase of the waning moon changes from gibbous to last quarter at noon (Pacific Daylight Time) on Friday the 25th. On following mornings it appears in crescent phase. The moon’s rising time retreats from 10:59 p.m. on the 23rd to 3:51 a.m. on the 30th. Just before dawn on Sunday the 27th, the moon will fit into the same binocular field of view as the Pleiades cluster in Taurus.
Evening hours in late July are a fine time to pick out the constellation Scorpius the Scorpion, low in the southern sky. Scorpius is one of the few constellations that looks something like what it is named after. Start with its brightest star, orange Antares, marking the heart of the scorpion. Antares is due south at 9 p.m., and 29 degrees high. The front of the body is formed by three stars arranged almost vertically about 8 degrees to the right of Antares. The body of the scorpion is a trail of stars that descend from the left of Antares, and loop to the left and back up well above the horizon. The figure ends with two bright stars marking the scorpion’s stinger.
Free public sky viewing, day and night, is available through Griffith Observatory’s telescopes until 9:45 p.m., six days a week, Tuesday through Sunday. The next public star party, held by members of the Los Angeles Astronomical Society and the Los Angeles Sidewalk Astronomers, will be held on the Observatory’s front lawn on Saturday, August 9. For Observatory information, please visit our website, www.griffithobservatory.org, or call (213) 473-0800.
