Lunar eclipse. Time-lapse image of a total eclipse of the Moon. Star trails are seen around the Moon. A total eclipse of the Moon occurs when the Moon passes into the shadow cast by the Earth. Even when totally shadowed the Moon does not generally disappear. It is still visible due to the sunlight refracted onto its surface by the Earth's atmosphere. Star trails are seen on long-exposure photographs due to the apparent motion of the stars caused by the Earth's rotation. The Moon appears brightest when totally eclipsed here as the exposure of that frame was longer than the others. Photographed on 23rd March 1997 from Zion National Park, Utah, USA.