2011 03 19 “Super Moon”

2011 03 19/2011 03 20 Full Moon 1 hour from Perigee, a.k.a. Super Moon

2011/03/19 Super Moon - by Paul Rix, DSI Pro III, ED 80

Diagram of Moon's orbit to Earth - NASA

The Moon has an elliptical orbit around Earth. The term “perigee” means that it has reached its shortest distance to earth. Likewise, “apogee” means that the Moon has reached the furthest distance in its orbit around Earth. Add a full Moon into the equation, and you could be in for a treat. Although a full Moon near perigee happens a little more often, the March 19th 2011 full Moon was only an hour away from perigee, making it a little more special. This event only happens approximately every 18 years, making near-perfect conditions for a Super Moon. The Moon’s apparent size will change ~14% from apogee to perigee.

2011/03/19 by Erika Rix

At any given night, the Moon often looks larger in the sky near the horizon as seen at sunrise or sunset. This illusion appears more pronounced when “near” trees or buildings; however, you can hold your thumb in the air to cover the Moon at various times of the night and see that its size hasn’t changed during the course of that night.

At any given month or year, the moon may appear larger or smaller because of how far away from Earth during the course of its orbit. For instance, at my location, it reached full Moon at 20:51 UT on March 19, 2011. At that moment, the Moon was 359,573 km away from Earth.. One year ago on Mar 19th, it was 384,138 km away. Five years ago, 397,291 km away. Coloring of the Moon near the horizon may have lovely shades of orange, tan, or yellows. This is mainly due to our atmospheric conditions such as haze or air pollution filtering out light’s wavelengths.

2011/03/19 with Lunar aureole by Erika Rix

Paul and I (along with Nigel who chose to be my astro-dog companion of the night) were treated with beautiful views of an aureole throughout the night. It was an added bonus to the perigee. For more views of aureoles, please visit the archive for Lunar Atmospheric Phenomena.

Additional Resources concerning the Super Moon 2011:


~ by Erika Rix on March 20, 2011.

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