September Perigee Moon

18sep-perigee_moon   The Moon reaches perigee, (minimum distance from Earth), this month on Sunday September 18th. At that time the Moon will more or less be at a distance of 28.77 Earth diameters (361,896 km or 224,872 miles) from the Earth.
Does our Moon actually go around the Earth as this graphic shows? From our perspective on the Earth the Moon appears to circle around the Earth. However, in reality, the Moon orbits the Sun together with the Earth*

The just past full waning gibbous Moon rises before midnight on the 17th and is easily seen brightening the western horizon before sunrise on the 18th. The Moon is near one of the outermost planets, and a couple of the Dwarf Planets. All of which are rendered ‘invisible’ as a result of the reflected light from the Moon.

*Click here to read my 2006 Scope on the Sky column “The Real Shape of the Moon’s Orbit”. (PDF)

Read this very informative article about the Earth-Moon system and their orbital motions, written by Joe Hanson. “Do We Orbit the Moon?”


Click here to go to the Qué tal in the Current Skies web site for monthly observing information, or here to go to bobs-spaces.

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