Bob Moler's Ephemeris Blog

This is Ephemeris for Friday, December 12th. Today the Sun will be up for 8 hours and 51 minutes, setting at 5:02, and it will rise tomorrow at 8:11. The Moon, 1 day past last quarter, will rise at 1:58 tomorrow morning.

We are ramping up to the most active meteor shower of the year, the Geminid meteor shower. And it has been getting more active over the years. The peak will be about 2 AM Sunday morning with a 30% Moon rising shortly after 3. The radiant is the point in space where the meteors seem to come from, which is near the star Castor in the constellation Gemini from which the shower gets its name. Unlike most meteor showers, the Geminids will be visible all night. The meteors will be seen all over the sky, but they all can be traced back to the radiant. The body responsible for this meteor shower is an asteroid rather than a comet with the name 3200 Phaethon, which comes very close to the Sun.

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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