Question

like the moon’s shadow, earth’s shadow has an umbra and a penumbra. there are different types of lunar eclipses. it depends on which part of earth’s shadow the moon moves through. unlike solar eclipses, all lunar eclipses can be seen from any place on earth where it is nighttime.

total and partial lunar eclipses

when the entire moon moves through earth’s umbra, a total lunar eclipse takes place. during a total lunar eclipse, the moon’s appearance changes slowly as it moves. the moon moves into earth’s penumbra. it then moves into earth’s umbra. next, it moves back into earth’s penumbra. then it moves completely out of earth’s shadow.

you can still see the moon when it is completely in earth’s umbra. earth blocks most of the sun’s rays. however, some of the rays deflect off earth’s atmosphere and into earth’s umbra. this reflected sunlight has a reddish color. it gives the moon a reddish tint during a total lunar eclipse. the deflection of some of the sun’s rays also explains why you can see the unlit part of the moon on a clear night. astronomers often call this earthshine.

explore/explain • page 79

enter your answer.

explain why can you still see the moon during an eclipse? check your answer.

Explanation:

During a lunar eclipse, Earth blocks most of the Sun's rays. However, some Sun's rays deflect off Earth's atmosphere and enter Earth's umbra (the shadow region where the Moon is during a total lunar eclipse). This reflected sunlight, which has a reddish color, illuminates the Moon, allowing us to still see it (giving it a reddish tint in total lunar eclipses). Also, this deflection of Sun's rays (Earthshine) can make the unlit part of the Moon visible on clear nights, and during eclipses, this process still occurs to some extent to let us see the Moon.

Answer:

During a lunar eclipse, Earth blocks most Sun's rays, but some rays deflect off Earth’s atmosphere, enter Earth’s umbra, and illuminate the Moon (giving it a reddish tint in total eclipses). This reflected sunlight (Earthshine - related process) allows us to see the Moon.