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This is the Griffith Observatory Sky Report through August 21st, 2020. Here’s what’s happening in the skies of southern California.
Bright planets are visible from dusk to dawn, and they, along with the moon, will provide a lot of interesting sights for the unaided eyes as well as through binoculars and telescopes.
The giant planets, Jupiter and Saturn, are already noticeable in the southeast sky before nightfall. They are separated by eight degrees, and Jupiter, the brighter of the pair, appears to lead Saturn westward through the night while their position arcs from the southeast to the southwest as the result of Earth’s rotation. The planets are highest in the south at 11:00 p.m., and both planets set in the west-southwest by 4:00 a.m.
Jupiter’s four largest moons, the Galilean satellites, may be glimpsed with ordinary binoculars, through which they appear as tiny stars huddled in a line around the bright planet. Moons may sometimes be invisible in front of Jupiter, behind the planet, or in its shadow, so sometimes fewer than four are visible, as their orbital revolutions around Jupiter bring them in and out of view. Comparing views at different times, even only hours apart, may allow you to notice their shifting positions.
Through a telescope, the details of Jupiter’s banded clouds and the occasional shadows of its moons may be examined. Look for Jupiter’s colorful oval storm, the Great Red Spot, when it is visible to West Coast observers at 10:00 p.m. on the 16th and 18th.
Saturn’s amazing rings are visible through most telescopes. Telescopes larger than three inches in diameter should be able to show Cassini’s Division, a separation between the outer, narrow “A” ring, and the inner, broad “B” ring. Saturn’s clouds are organized into broad stripes, of lower contrast than Jupiter’s.
At 11:00 p.m. look to the East to see the brilliant copper glow of the planet Mars. It is well placed high above the horizon for a clear telescopic examination by 1:00 a.m., and at dawn it is 61 degrees above the meridian in the south. Well adjusted telescopes may show the bright white oval of the rapidly shrinking South Polar Cap, and the dark markings of the planet’s highland regions amidst the orange hue of its dusty deserts. The angular size of Mars will grow from 17 to 23 arcseconds between now and its closest approach to Earth in October, but it is already an interesting object to observe.
The gleam of the brightest planet, Venus, is eye-catching in the east between 4 a.m. and sunrise. Through a telescope, the gibbous phase will become more obvious morning by morning.
The waning crescent moon appears next to Venus on the 15th. On following mornings, the moon may be seen to the lower left of Venus until about 5:30 a.m. on the 17th, only about 14 hours before it is new. The waxing crescent moon will might next be seen just above the western horizon at about 8:00 p.m. on the 19th. The moon will become easier to see as it moves higher on the following evenings.
Because of measures in place that are intended to reduce the spread of the COVID-19 Corona virus, Griffith Observatory remains closed until further notice. Consequently, all public telescopes are closed, and all public events have been cancelled. Please check the Griffith Observatory homepage for current information and continued updates of the situation.
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From Griffith Observatory, I’m Anthony Cook, and I can be reached at Anthony.Cook@lacity.org.