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Extra: 03/17/2015 – A geomagnetic storm is raging now
Looks like we’re in for aurorae A.K.A. northern lights tonight. There were displays of the aurora this morning over the northern tier of states according to spaceweather.com. It still could be going on tonight.
Tip ‘o the old observers cap to Don Flegel and Spaceweather.com.
03/17/2015 – Ephemeris – Jupiter’s cloud stripes
Ephemeris for St. Patrick’s Day, Tuesday, March 17th. The Sun will rise at 7:51. It’ll be up for 11 hours and 59 minutes, setting at 7:51. The Moon, 3 days before new, will rise at 6:37 tomorrow morning.
Jupiter is the one planet that we can see detail on with telescopes in the evening sky. Venus is so bright that it is hard to even see its gibbous phase. Actually the best way to see Venus is during the day with the blue sky around it. Jupiter is a big planet, 11 times the Earth’s diameter and 1,300 times it volume. Despite this it is only 318 times the Earth’s mass, so much of its mass is the atmosphere. It’s rotation rate is just under 10 hours at its equator. This drops with latitude, so its atmosphere is twisted into alternate belts and zones. The belts are dark brown while the zones are lighter. They move around the planet at different speeds causing storms that their boundaries. The Great Red Spot is a anticyclone in the south.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Jupiter by Scott Anttila November 14, 2011. With shadow on the planet and the Great Red Spot.
Bob Moler's Ephemeris Blog 