Careful skywatchers in the eastern half of North America can watch the full Moon just graze Earth's shadow.
On the evening of Friday, October 18th, the full Moon will glide across the pale outer fringe (penumbra) of Earth's shadow. Mid-eclipse occurs at 23:50 UT (7:50 p.m. Eastern Daylight Time), when the Moon's southern limb will be a quarter of a lunar diameter away from the unseen edge of Earth's umbra, the dark core of its shadow.
Unusual shading on the southern half of the Moon should be fairly plain. Look for the penumbral shadow to move from (celestial) east to west across the disc. You might be able to detect lesser traces of penumbral shading for about 45 minutes before and after mid-eclipse.
As the map at right shows, the event will also be visible in evening from the Caribbean and South America. In Europe and Africa, it happens in the middle of the night with the Moon high in the sky. For observers in western, central, and southern Asia, it happens before or during dawn on the 19th.