http://science.nasa.gov/science-news/science-at-nasa/2011/16mar_supermoon/ 17 percent in the KSL broadcast is an over statement. Looking at today's 3-19-2011 EPOD ( http://epod.usra.edu/ ), if you take the extreme maximum and extreme minimum distances of the Moon and the arc size of the Moon at those positions, then you can say that the arcsize change is 17 percent - _using the extreme minimum as the denominator. Two photos in today's EPOD (3-19-2011) are illustrative. They use the Moon near an extreme minimum of 356,790 at an apparent size of 34 arcsecs and near a maximum of 406,357 at 29.74 arcsecs. 14% approx equals ( (34.06-29.74) / 29.74 ). Since the change is size would _normally_ be measured from the _mean apparent size_ of the Moon, the variation is really about half that - or about 7 percent or a change in apparent size of about 2 arcsecs (34.06-29.74/2). The human eye, you cannot even see 2 arcsecs with less than 30 power of magnification. A 4 arcsec change is going to take 15 power of magnification to be detectable above a AFOV 1 arcmin change. In the unlikely event that the clouds have a sucker hole break at moonrise SLC at 8:04 MDT local time, Dr. Phillips's observing point that the full Moon may be particularly beautiful as it rises (yesterday) tonight and tomorrow (in combination with the Moon illusion) is a good reminder. I'll be looking. (Humm, I may even pre-set up a tripod mounted DSLR.) - Clear Skies (Did I forget to mention today is spring?) - Kurt P.S. - Happy Spring!