Weekly Sky Report
The Griffith Observatory Sky Report
This is the Griffith Observatory Sky Report through April 25th, 2018. Here’s what’s happening in the skies of southern California.
The moon waxes from crescent to first quarter on the afternoon of the 22nd, and its phase is gibbous after that. It rises later each day and lights the nighttime sky about an hour longer on each successive night. It sets at 10:31 p.m. on the 18th and 3:51 a.m. on the 25th.
On Saturday the 21st, the moon will set at 12:37 a.m., which is perfect for the maximum of the annual Lyrid meteor shower, which just gets underway as the moon sets, and it will continue to strengthen until dawn starts, at 4:45 a.m. The radiant of the Lyrids, the point in the sky from which the meteors in this shower seem to stream, is close to the star Vega, the brightest star in the constellation Lyra the Lyre. Vega is low in the northeast sky at midnight, and it arcs upwards from then until it is directly overhead just before dawn. The Lyrids typically produce about 18 meteors per hour in dark skies, free from urban light pollution. On several occasions, however, the rate has exceeded 90 meteors per hour.
Venus is the brilliant object in the west-northwest sky, and is visible from sunset until 9:30 p.m. In fact, Venus is so bright that on a clear day, it can be seen as a bright point against the blue sky even before the sun sets.
By the time Venus sets, the second brightest planet, Jupiter, can be seen on the other side of the sky, above the east-southeast horizon. Jupiter gleams against the backdrop of stars of the constellation Libra the Scales. Jupiter is highest in the south when it crosses the meridian at about 2:00 a.m. Observers with telescopes aimed at Jupiter at 2:00 a.m. should be on the lookout for Jupiter’s famous oval storm, the Great Red Spot on the 20th, 23rd, and 25th as it will then be on the side of Jupiter facing Los Angeles.
The other bright outer planets, Mars and Saturn, are both in the constellation Sagittarius the Archer, and both are above the east-southeast horizon by 1:30 a.m. Mars and Saturn are high in the south at dawn, with distinctly orange Mars about 10 degrees to the left of golden Saturn, an angle about equal to that covered by your clenched fist held out at arm’s length.
While high telescopic magnification and patience are required in order to observe markings on the planet Mars, the rings of Saturn are much easier to see and they look spectacular through nearly any telescope.
Binoculars will help you to spot the innermost planet, Mercury, when it appears five degrees above the eastern horizon about 30 minutes before sunrise – at 5:50 a.m., starting on the 20th. Mercury will become easier to see on following mornings.
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. 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, May 19th.
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From Griffith Observatory, I’m Anthony Cook, and I can be reached at firstname.lastname@example.org.