Bob Moler's Ephemeris Blog

This is Ephemeris for Tuesday, January 6th. Today the Sun will be up for 8 hours and 58 minutes, setting at 5:18, and it will rise tomorrow at 8:19. The Moon, 3 days past full, will rise at 9:25 this evening.

One of the more obscure constellations around is Eridanus, which depicts a river. At 8 PM the river, marked by dim stars, starts near the lower right corner of Orion, near the bright star Rigel and flows to the right then down a little way, then to the lower left, and again to the right, to the southern horizon. One has to travel to the far south to see the southern terminus of the river, the bright star Achernar. Writers over the ages have seen here the Nile, the Rhine and the Earth circling river Ocean of the flat earth days. To most Greeks, including Ptolemy it was simply the River. The earlier Greek astronomer Hipparchus called it the River of Orion, alluding to Orion’s star Rigel as its source. The southern part of the river was added when astronomers made it far enough south.

The astronomical event times given in this blog are for the Traverse City/Interlochen area of Michigan (Lat 44.7° N, Long 85.7° W; EST, UT – 5 hours) unless stated otherwise. Times will be different for other locations.

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