This may have already have been answered but here goes anyway. "Magnitude" is a term that is freely used to describe what I will call the "luminance" of the moon and satellites. My purpose for asking about the Moon's brightness is to help me to try to understand the meaning of magnitude and how a person can compare the predicted (and apparent) magnitude of a satellite with the Moon's sunlit limb and its dark limb. I found a listing of the standard magnitude of the full moon in a SeeSat Archived message from Richard Keen (richard.keen@kingsmarket.com) dated: Sat Mar 18 2000 - 21:46:13 PST. See, "moon's brightness" at http://satobs.org/seesat/Mar-2000/0250.html . There Richard said that his text listed the full moon as having a value of magnitude -12.7. A response called, "On calculating the magnitude of the Moon" came from: Frank E. Reed (FrankEReed@aol.com). See: http://satobs.org/seesat/Mar-2000/0267.html In his response Frank directed us to: http://hotel04.ausys.se/pausch/comp/ppcomp.html#15 which states that in determining the magnitude of the moon or the planets one must consider, "....the apparent diameter of the planet"....and.... "the phase angle and the elongation." In that article the area is important to perceived magnitude yet I found information that describes comparing a totally eclipsed moon with stars, i.e. points of light! See: http://correio.cc.fc.ul.pt/~apereira/lun_ecl_9709.html There I read, "Regarding the forthcoming lunar eclipse, we would like to encourage observers to actually attempt estimating the moon's total visual magnitude during totality by using reversed binoculars. The brightness of the moon as viewed through the reversed binoculars is compared to the brightness of stars as seen directly with the naked eye." Sooooo, is there any way to compare the numerical text "magnitude" of the sunlit or shaded part of the moon with the predicted "magnitude" of a satellite? Thanks, Tom Iowa ----------------------------------------------------------------- Unsubscribe from SeeSat-L by sending a message with 'unsubscribe' in the SUBJECT to SeeSat-L-request@lists.satellite.eu.org http://www.satellite.eu.org/seesat/seesatindex.html
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