Even though this autumn's apparition puts Mars' maximum apparent size
at 20 arcseconds rather than 25 as in August 03, it may well be better
for most northern hemisphere residents because Mars will be much higher
in the sky and therefore yield steadier views.

From http://www.tnni.net/~dustymars/2005_MARS.htm - "Mars will appear
smaller in 2005 than it was in 2003. During closest-approach in 2005
Mars will be 4.9 seconds of arc smaller in apparent diameter than it
was at closest approach in 2003; however, it will be 32 degrees higher
in the sky for Northern Hemisphere observers and that will tend to
negate the effects of a smaller apparent diameter. "

The Moon is 30 arcMINUTES in size, not arcSECONDS.