Bob Moler's Ephemeris Blog

Tuesday, April 12th.  The sun will rise at 7:04.  It’ll be up for 13 hours and 19 minutes, setting at 8:23.   The moon, 1 day past first quarter, will set at 4:16 tomorrow morning.

The planet Saturn, now rising up in the southeastern sky is always the most wonderful sight in a small telescope.  The rings are slowly opening to the sun, however for us on the earth, whose orbit is tilted by about 2 and a half degrees to the Saturn’s orbit of the sun, the rings appear to be closing just a bit right now.  After June they will open up again.  Tonight a small telescope will also reveal Saturn’s largest satellite or moon which  will be off the edge of the longest extent of the rings to the east of Saturn.  Titan is the second largest moon in the solar system, after Jupiter’s Ganymede.  It is larger than the planet Mercury and the only moon with a substantial atmosphere.  Titan’s surface atmospheric pressure is slightly greater than the earth’s.

* Times are for the Traverse City/Interlochen area of Michigan.  They may be different for your location.

Addendum

Saturn and some of its bright moons for April 12, 2011. Created using Cartes du Ciel

Titan is the easiest moon to see.  Rhea is more difficult.  The others being close to Saturn tonight may be impossible to spot.  The free programs Cartes du Ciel and Stellarium will show the positions of Saturn’s satellites.  See the Free Astronomical Software links in the right.  Stellarium does have a problem getting the satellite brightness right, they’re too bright.