06/13/2016 – Ephemeris – Two early astronomers honored by prominent craters on the Moon
Ephemeris for Monday, June 13th. Today the Sun will be up for 15 hours and 32 minutes, setting at 9:29, and it will rise tomorrow at 5:56. The Moon, 1 day past first quarter, will set at 2:54 tomorrow morning.
The Moon tonight sports two craters, named for important astronomers near the south end of the of our satellite. The first, the smaller of the two sticks out for its sharp edges and dark shadows. It is Tycho, which at full moon exhibits moon encircling rays. It’s 52 miles (86 km) in diameter. Named for Tycho Brahe that last great naked eye astronomer in the 16th century, whose precise positions of Mars allowed Johannes Kepler to formulate his Three Laws of Planetary Motion. Clavius is a large crater south and closer to the terminator, the sunrise line, than Tycho. It has a curious arc of several smaller craters on its floor. Clavius is 136 miles (225 km) in diameter. Clavius completed work on the Gregorian calendar.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.