Space.com: Between this evening and tomorrow morning, 2021 December, astronomers and the general public in North and South America are in for a treat: a total lunar eclipse. A lunar eclipse occurs when Earth lines up directly between the Sun and the Moon, blocking the Sun’s rays and casting a shadow on the Moon. As the Moon moves deeper into Earth’s shadow, it changes color from gray to orange or red, because indirect sunlight still passes through Earth’s atmosphere and casts a glow on the Moon. Space.com provides links to a lunar eclipse viewing guide, photos of a total lunar eclipse, a table showing the times of the different states of the eclipse in different time zones, and a star chart.