Bob Moler's Ephemeris Blog

This is Ephemeris for Friday, April 8th. Today the Sun will be up for 13 hours and 8 minutes, setting at 8:19, and it will rise tomorrow at 7:09. The Moon, 1 day before first quarter, will set at 3:58 tomorrow morning.

The Artemis missions are to land near the South Pole of the Moon. Unlike the Earth’s 23 and a half degree axial tilt the Moon’s is only a degree and a half, so there is little month long variation of the Sun angle, though the Sun’s direction along the horizon revolves 360 degrees over 29 and a half days, the length of its orbit of the Earth. It should make for quite a challenge to land the human lander safely near the lunar South Pole. The lander has to choose a spot in sunlight to land that’s relatively smooth. The reason for the attraction of the lunar South Pole is the presence of water ice in permanently shadowed craters near and at the pole. The Moon’s North Pole isn’t as heavily cratered, with fewer permanently shadowed craters.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT – 4 hours). They may be different for your location.

Addendum

Lunar South Pole Flyover area with approximate South Pole marked based on Virtual Moon Atlas. Did you note a theme in some crater names? Click on the image to enlarge it. Credit: NASA/LRO.

The South Pole of the Moon, where the presence of water ice is detected by the absorption of neutrons by the hydrogen atoms in the ice. Credit NASA/GSFC/SVS/Roscosmos.