The Griffith Observatory Sky Report
This is the Griffith Observatory Sky Report for the week ending Wednesday, May 29, 2013. Here is what’s happening in the skies of Southern California:
An interesting dance of three planets can be seen all week during evening twilight. Throughout the week, the brightest planet, Venus, will be located about 7 degrees high (a little less than the height of your clenched fist seen from arm’s length) above the west-northwest horizon 30 minutes after sunset. Starting Wednesday the 22nd, Jupiter, the second brightest planet, will be obvious, about 7 degrees to the upper left of Venus. Binoculars will then help you to also find the innermost planet, Mercury, nearly 2 degrees to the lower right of Venus. While Jupiter draws closer to Venus night by night, Mercury will move higher, towards Jupiter, causing the nightly arrangement of planets to change. Mercury will appear only 1.3 degrees to the upper right of Venus on Friday the 24th, and by Sunday the 26th, the three planets will form an almost equilateral triangle 2 degrees on a side, with Venus at the bottom and Mercury to the upper right of Jupiter. By Wednesday the 29th the triangle will have stretched into a line 5 degrees long, with Mercury at the top and Jupiter at the bottom.
As Mercury, Venus, and Jupiter set in the west-northwest, the ringed planet, Saturn, appears in Virgo the Maiden in the southeast. Saturn is highest, in the south, at 11:00 p.m., and sets in the west-southwest as dawn starts. The moon appears to the lower right of Saturn on the 22nd.
The moon waxes from gibbous phase to full on Friday the 24th at 9:25 p.m., P.D.T. A few minutes before then, at 9:10 p.m., P.D.T., the moon will be in the middle of a brief but invisible lunar eclipse that lasts only from 8:42 to 9:37 p.m., P.D.T. This will be a grazing penumbral eclipse, in which the southern 4-percent of the moon will fade imperceptibly as it brushes against the outermost, fuzzy portion of the earth’s shadow (the penumbra). As undetectable as this eclipse is expected to be, it is the start of a new cycle of eclipses, a periodic line up of sun, earth and moon that results in a series of evolving lunar eclipses that will occur every 18 years 11 days and 8 hours–a Saros cycle. This new cycle, lunar Saros number 150, will produce a total of 71 eclipses through AD 2987, including partial umbral (central shadow) eclipses starting in AD 2157 and total eclipses commencing in AD 2572.
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 Tuesday-Sunday before 9:30 p.m. Check our website for our schedule. The next 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, June 15.
From Griffith Observatory, I’m Anthony Cook and I can be reached at email@example.com.