Post by Centaur on Mar 14, 2011 10:48:04 GMT -6
The Full Moon of 2011 MAR 19 will occur near the time of perigee. The Moon was most recently closer during the Full Moon of 2008 DEC, not 1993 as reported in the popular media. Unfortunately for us North Americans, it will be daytime with the Moon beneath the horizon when it is most fully illuminated and at the time of perigee. For us the nights of March 18/19 and March 19/20 will serve as equally good consolation.
Full Moon at perigee occurs once every 14 synodic months (lunar months of 29.53 days). I’ve created a chart illustrating various factors for the next 15 Full Moons, the first and last occurring near perigee. It can be seen at www.curtrenz.com/moon
Although this month’s Full Moon will appear particularly large due to its occurrence near the time of perigee, the previous two Full Moons were actually brighter. That’s because the Earth/Moon duo was closer to the Sun, and the Moon was nearer to the ecliptic thus enhancing the opposition flash. These factors increased the number of photons being reflected back toward us.
The brightness factor on my Full Moon chart gives a value of 1.00 when both the Sun and Full Moon are at their mean distances from Earth, and the Moon is on the ecliptic. Of course that would be during a total lunar eclipse, but for the standard it is assumed that sunlight passes unimpeded through the Earth. For a Full Moon that actually goes into eclipse, the brightness factor is an average for the moments just before and after the Moon touches the Earth’s penumbra.
Photos and discussions of this month’s especially large Full Moon would be welcome additions to this thread. Below is the picture I took of the rising Hunter’s Moon on 2010 OCT 22.
Full Moon at perigee occurs once every 14 synodic months (lunar months of 29.53 days). I’ve created a chart illustrating various factors for the next 15 Full Moons, the first and last occurring near perigee. It can be seen at www.curtrenz.com/moon
Although this month’s Full Moon will appear particularly large due to its occurrence near the time of perigee, the previous two Full Moons were actually brighter. That’s because the Earth/Moon duo was closer to the Sun, and the Moon was nearer to the ecliptic thus enhancing the opposition flash. These factors increased the number of photons being reflected back toward us.
The brightness factor on my Full Moon chart gives a value of 1.00 when both the Sun and Full Moon are at their mean distances from Earth, and the Moon is on the ecliptic. Of course that would be during a total lunar eclipse, but for the standard it is assumed that sunlight passes unimpeded through the Earth. For a Full Moon that actually goes into eclipse, the brightness factor is an average for the moments just before and after the Moon touches the Earth’s penumbra.
Photos and discussions of this month’s especially large Full Moon would be welcome additions to this thread. Below is the picture I took of the rising Hunter’s Moon on 2010 OCT 22.
