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This is the Griffith Observatory Sky Report through October 24th, 2018. Here’s what’s happening in the skies of southern California.
The Orionid meteor shower reaches its peak on the morning of Monday, October 22nd. Bright moonlight will hamper viewing until 4:58 a.m. on that morning, allowing only about half an hour of viewing under a dark sky. The meteor activity of the Orionids usually changes very little on the dates close to the peak, so the mornings of Saturday, October 20th and Sunday, October 21st, may also provide excellent viewing opportunites. On those mornings, the moon sets at 3:04 a.m. and 4:00 a.m., respectively, and the meteors can be observed until the start of dawn, at 5:36 a.m. From a dark sky location, free from urban light pollution, between 10 and 20 Orionid meteors may be observed per hour. Orionid meteors start as dusty particles, called meteoroids, that were shed from comet Halley at past visits to the inner solar system, and that have become spread out along the comet’s orbit. Meteoroids become visible as meteors when they collide with Earth’s atmosphere. Moving with a velocity of 27 miles per second, the particles are completely vaporized while they are at least dozens of miles above the ground. Orionid meteors appear to stream from the upraised club of the constellation Orion the Hunter, near the bright orange star Betelgeuse.
Jupiter, in the constellation Libra the Scales, and currently the brightest planet visible, is low in the southwest sky during evening twilight. Saturn, in Sagittarius the Archer appears as a golden star to Jupiter’s upper left. Mars, now fainter than Jupiter, glows with its distinctive orange hue against the dim backdrop provided by the stars of Capricornus the Sea Goat.
Use a telescope to see the distinctive features of the planets. Jupiter will show up to four of its many moons and the banded patterns of its clouds. Saturn is surrounded by its beautiful system of rings. The distance of Mars is still increasing after last July’s close approach to Earth. As a result, the planet now appears so small that its surface details require the use of telescopes of six-inch or larger diameter to see them. Jupiter sinks below the west-southwest horizon at 7:40 p.m., followed by Saturn at 10:40 p.m. and Mars at 1:20 a.m.
The moon’s phase is waxing gibbous until the 24th, when it is full.
The International Space Station will outshine the planets as it moves through the Los Angeles sky on the evening of the 18th. It will be visible between 6:34 and 6:40 p.m. while it moves from the northwest to the south-southeast horizon. It will be 48 degrees above the southwest horizon at its highest, at 6:37 p.m.
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, October 20th.
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From Griffith Observatory, I’m Anthony Cook, and I can be reached at griffithobserver@gmail.com.