04/16/2013 – Ephemeris – The moon’s strange orbit
Ephemeris for Tuesday, April 16th. The sun rises at 6:56. It’ll be up for 13 hours and 32 minutes, setting at 8:28. The moon, 2 days before first quarter, will set at 2:13 tomorrow morning.
The fat crescent moon appears high in the sky. It appears in a part of the sky where the sun will be in early July. The moon follows a path nearly in the plane of the earth’s orbit , but a bit tilted from it by an angle of 5 degrees. This is unusual. Most planet’s major satellites orbit their primary in it’s equatorial plane, like our geostationary communication satellites, though none them orbit in one of their planet’s days. The moon orbits the earth, but due to its great distance of 60 earth radii, or 240 thousand miles also is very much gravitationally affected by the sun. Apparently one of its effects was to pull the moon close to the the earth’s orbital plane. If you like eclipses this is a good thing. It makes eclipses much more frequent than if the moon orbited over the earth’s equator.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
