... The Umbra of Earth . ... Shaped like a cone extending into space, it has a circular cross section most easily seen during a lunar eclipse . For example, last Saturday the Full Moon slid across the southern half of Earth's umbral shadow, entertaining moonwatchers around much of the planet. ... The result shows the relative size of the shadow's cross section at the distance of the Moon, as well as the Moon's path through Earth's umbra . ... 2011 2012 . ... Publications with keywords: lunar eclipse . ...