October Moon at Perigee

16oct-perigee_moon   The Moon reaches perigee, (minimum distance from Earth), this month on Sunday October 16th. At that time the Moon will more or less be at a distance of 28.05 Earth diameters (357,861 km or 222,364 miles) from the Earth.
   The Moon reaches perigee Sunday at 23:47 UT (6:47 pm CDT) and this is less than 20 hours after it was at full Moon phase also on Sunday but at 4:23 UT, (11:23 pm CDT October 15th). Since the full Moon is this close to its closest to the Earth for this orbit the full Moon could be considered one of the ‘Super Moons’ this year.
   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*

   On the day of the lunar perigee the 16-day old just past full waning gibbous Moon rises at around sunset local time and is over the southwest horizon at sunrise the following morning. Two of the Dwarf planets, Eris and Ceres are near the Moon but due to their respective apparent magnitudes (Ceres 7.0; Eris 18.6) and the bright reflected light from the Moon the two are all but invisible. Interestingly these two represent two similar but very different types of Dwarf Planets – Ceres is within the main asteroid belt at a distance of 1.9 AU (176,616,033 miles; 284,235,954 km) while Eris is in the outer regions of the solar system at a distance of 95 AU (8,830,801,690 miles; 14,211,797,715 km) from the Earth.
   *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.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.