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This is the Griffith Observatory Sky Report through January 31, 2018. Here’s what’s happening in the skies of southern California.
A total eclipse of the moon, visible at Los Angeles, will occur during the early morning hours of Wednesday, January 31. A lunar eclipse is caused when the full moon passes through the shadow cast by the Earth.
Subtle dimming of the lower left edge of the moon should be noticeable by about 3:15 a.m., after it is half-immersed in the fuzzy outer shadow of the earth, the Earth’ penumbra.
A distinct dark bite out of the edge of the moon will be visible at 3:48 a.m., the start of the moon’s passage into the Earth’s central shadow, the umbra. It will take 63 minutes for the moon to be completely immersed in the umbra.
The total eclipse begins at 4:51 a.m. Although the moon is completely within Earth’s shadow, it does not vanish, but it remains visible, glowing with an eerie red or copper hue. This is the result of the red rays of sunlight being filtered and bent into the Earth’s shadow by its atmosphere and on to the moon; an observer on the moon would then see the dark face of Earth surrounded by a blazing red ring, the light of all the Earth’s sunrises and sunsets occurring then. Binoculars will help you to see the variety of the changing shades and colors of the moon during totality. During totality, binoculars can also be used to see the “Beehive” star cluster in the constellation Cancer the Crab. It will be located four degrees to the right of the moon, within the same binocular field-of-view as the moon.
Totality will last for 76 minutes, and dawn starts at 5:25 a.m., four minutes before the midpoint of the eclipse. Totality ends at 6:08 a.m., and the moon is still partially within the umbra when it sets at 6:56 a.m., five minutes after sunrise at Los Angeles. More information is available on the Griffith Observatory eclipse Webpage.
The moon’s phase changes from waxing crescent to first quarter on the 24th, then it is gibbous on the nights leading up to the full moon. The January 31st full moon is the second full moon of the month, also called a “blue moon.” According to the New Mexico Museum of Natural History, a blue moon lunar eclipse has not happened since 1866 and another will not occur again until 2028. March will also have a blue moon, and as a result, February will be left with no full moon at all!
The bright planets Jupiter, Mars, and Saturn can be seen in a line in the southeast sky at dawn. Jupiter is the highest and brightest of these, nearly toward the south, and in the constellation Libra the Scales. Orange-hued Mars is to the lower left of Jupiter and it moves from Libra to the adjacent constellation Scorpius the Scorpion on the 30th.
Continuing the line made by Jupiter and Mars, to a point more than halfway to the southeast horizon, will lead you to golden Saturn, in the constellation Sagittarius the Archer. The bright object out of the line formed by the three planets and below Mars is the bright star Antares in the constellation Scorpius the Scorpion.
The International Space Station will pass over Los Angeles on Friday evening, the 25th. It will outshine everything but the moon as it crosses the sky from the west-northwestern horizon to the north-northeast between 6:24 and 6:29 p.m. It reaches its highest point 53 degrees above the northwest horizon a few seconds before 6:28 p.m.
Free views of the Sun during the day and of the moon, and other interesting 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, January 27, from 2:00 p.m. until 9:30 p.m.
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From Griffith Observatory, I’m Anthony Cook, and I can be reached at griffithobserver@gmail.com.