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This is the Griffith Observatory Sky Report through July 11, 2018. Here’s what’s happening in the skies of southern California.
By sunset, the brightest planet, Venus, is already noticeable in the northwest sky. Starting about half an hour later, at about 8:40 p.m., the planet Mercury resembles a bright star to the lower right of Venus. It is then midway between Venus and the horizon. Mercury sets at around 9:30 p.m., about an hour before Venus.
The brilliant object in the southern sky during the early evening is the planet Jupiter, in the constellation Libra the Scales. Jupiter moves into the southwest sky after darkness falls. It sets at about 2:40 a.m. on June 27th and at 1:40 a.m. on July 11th.
Golden planet Saturn, in Sagittarius the archer, is visible all night long on the 27th, when it is at opposition, at the point directly opposite the sun in the sky. On that date, Saturn is also accompanied by the full moon, also at opposition. Saturn is visible in the southeast sky as the sky darkens, and reaches the meridian in the south at 1:00 a.m., then it slowly heads to the southwest, where it sets at sunrise.
The orange planet Mars, in Capricornus the Sea Goat, gleams near the southeast horizon by midnight on June 27th, and by 10:00 p.m. on July 11th. Mars continues to brighten before its opposition and close approach to Earth at the end of the month. As a result, by July 6th, Mars will overtake Jupiter as the second brightest planet. Mars is highest in the south at 3:19 a.m. on June 28th, and at 2:24 a.m. on July 11th.
The moon is full on the 27th. Afterward, it wanes, becoming last quarter on July 6 and new on the 12th. After the 27th, it rises later after sunset each successive night. It first appears at 8:40 p.m. on June 28th, but not until 4:22 a.m. on July 11th.
All of these objects have fascinating details to observe through a telescope. Venus now shows a gibbous phase. The phase of Mercury is also gibbous until the 7th, when it appears half-illuminated. It is crescent on following evenings.
Jupiter’s four largest moons and its major cloud features are easy to observe through telescopes capable of a magnification of at least 50-power. The famous oval storm of Jupiter, the Great Red Spot, will face west coast observers at 9:00 p.m. on June 27th, 29th, July 1st, 4th, 6th, 9th, and 11th. Mercury, Venus, and Jupiter are currently featured through Griffith Observatory’s public telescopes.
Saturn’s rings are always exciting to see through a telescope. Because Saturn is at opposition on the 27th, the alignment of Sun, Earth, and Saturn cause the rings to appear much brighter than the planet for several days before and after the opposition. Saturn will become high enough in the sky to show through Griffith Observatory’s telescopes starting in mid-July.
Mars will be at opposition at the end of July, and the planet already appears relatively large to telescopic observers when it is well placed for observation, after 2:00 a.m. Mars is now covered by a planet-wide dust storm, and except for a portion of the Martian south polar cap that still appears bright, it is now nearly impossible to see any of the planet’s markings. Mars will be on the nightly viewing menu at Griffith Observatory when it is positioned for viewing in the early evening, starting in mid-August. Hopefully, the dust will have settled by then!
Free views of the Sun during the day and of the moon and planets 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. The next free 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 21st.
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From Griffith Observatory, I’m Anthony Cook, and I can be reached at griffithobserver@gmail.com.