This is the Griffith Observatory Sky Report for the week ending Wednesday, January 11, 2012. Here is what’s happening in the skies of Southern California:
The earth is closest to the sun, the point in its elliptical orbit called perihelion, on January 4 at 4:32 p.m., P.S.T. At that time the center of our planet will be 91,401,964 miles from the center of the sun, some 3,103,889 miles closer than we will be when farthest to the sun (at aphelion) on July 4.
The moon is brilliant this week. It waxes from gibbous to full, which it reaches on Sunday night, the 8th. It appears in waning gibbous phase on following nights.
Venus is the brightest planet and stands out in the southwest starting at sunset. Venus itself sets at 7:45 p.m. Through a telescope, the planet shows a gibbous phase and is 13 arcseconds in diameter.
Jupiter, in Pisces the Fishes, is the second brightest planet. It shines high in the southeast during evening twilight and sets shortly after 1 a.m. The giant planet appears 45 arcseconds wide through a telescope. High quality 7-power binoculars are enough to see Jupiter’s brightest moons crowded close to the planet’s disk.
The brightest star of the night-sky, Sirius in Canis Major, the Large Dog, is visible nearly all night long, following Orion the Hunter and moving from the southeast in the early evening to the southern sky around midnight, then setting in the southwest at dawn. Turbulence in our atmosphere often makes Sirius appear to sparkle with vivid colors, especially when near the horizon. Sirius is the closest star to the sun visible to the eye from Los Angeles, and is about 9 light-years away.
Rust-hued Mars is now the brightest object in Leo the Lion and can be found in the east starting after it rises at 10 p.m. Mars is best placed for observation high in the south at about 4:20 a.m. Through a telescope, the planet appears 10 arcseconds wide, with its north polar cap tilted towards us. This week, the dark regions of Mare Cimmerium and Mare Sirenum as well as the volcanic Tharsis region face Los Angeles observers before dawn.
The planet Saturn and the similarly bright star Spica of Virgo the maiden make a notable pair in the southeast after they rise at 1:00 a.m. until dawn. A telescope will reveal Saturn’s rings, now open 13 degrees in our direction.
The International Space Station will make a pass over Southern California on Wednesday, January 4, between 6:00 p.m. and 6:06 p.m., moving from northwest to southeast. The satellite, which should outshine Jupiter, will appear 59 degrees high in the southwest at 6:03 p.m. P.S.T. as seen from Griffith Observatory. Satellite viewing information for anywhere on earth is available from www.heavens-above.com.
Free public viewing of the sun during the day and of the moon, planets and other celestial objects at night, is available in clear weather Wednesday through Sunday with Griffith Observatory’s telescopes before 9:45 p.m. Check our website for our schedule. The next public star party of the Los Angeles Astronomical Society and the Sidewalk Astronomers is scheduled for Saturday, January 28.
The Sky Report is updated every Wednesday. It can be read-and now heard-on our website by following the Sky Information links. From Griffith Observatory, I’m Anthony Cook, and I can be reached at email@example.com.