Friday September 16th the full Moon, just one day after it was at descending node, passes through the Earth’s outer shadow. This sets up what is called a penumbral lunar eclipse, and during a penumbral eclipse the change in the brightness of the Moon does not decrease enough so that the eclipse is usually noticed. This eclipse will be visible across the continental United States. The Earth has two distinct shadows, an inner and much darker umbra, and the outer and fainter penumbra as this graphic shows.
For additional information about this or other eclipses go to the Hermit Eclipse web site.