Solar and Lunar Eclipses

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Eclipse Noun

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[ih-klips]

Back

Eclipse

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An astronomical event that occurs when one celestial body passes in front of another, blocking the light from it.

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Example: This diagram shows a lunar eclipse, where the Earth passes between the Sun and Moon, casting a shadow that darkens the Moon.

Front

Umbra Noun

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[um-bruh]

Back

Umbra

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The darkest, central part of a shadow where the light source is completely blocked by an opaque object.

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Example: This diagram shows the Moon blocking sunlight, casting a shadow on Earth. The umbra is the darkest, central part of this shadow, causing a total eclipse.

Front

Penumbra Noun

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[puh-num-bruh]

Back

Penumbra

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The lighter, outer part of a shadow where the light source is only partially blocked by an opaque object.

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Example: This diagram shows the Earth casting a shadow. The penumbra is the lighter, outer part of the shadow where the Sun is only partially blocked.

Front

Solar Eclipse Noun

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[soh-ler ih-klips]

Back

Solar Eclipse

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An event where the Moon passes between the Sun and Earth, causing the Moon's shadow to fall upon Earth.

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Example: This diagram shows how the Moon passes between the Sun and Earth, blocking the Sun's light and casting a shadow on a part of Earth.

Front

Lunar Eclipse Noun

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[loo-ner ih-klips]

Back

Lunar Eclipse

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An event where the Earth passes directly between the Sun and the Moon, casting Earth's shadow upon the Moon.

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Example: This diagram shows how a lunar eclipse occurs when the Earth passes directly between the Sun and Moon, casting a shadow that darkens the Moon.

Front

Annular Eclipse Noun

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[an-yuh-ler ih-klips]

Back

Annular Eclipse

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A solar eclipse where the Moon appears smaller than the Sun, creating a visible ring of sunlight around it.

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Example: This diagram shows an annular eclipse occurs when the Moon is too far to completely block the Sun, causing its antumbral shadow to create a 'ring of fire'.

Front

Penumbral Lunar Eclipse Noun

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[puh-num-brul loo-ner ih-klips]

Back

Penumbral Lunar Eclipse

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A subtle lunar eclipse where the Moon passes only through Earth's lighter, outer shadow, known as the penumbra.

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Example: During a penumbral lunar eclipse, the Moon passes through the Earth's faint outer shadow, called the penumbra, as shown by the alignment of the Sun, Earth, and Moon.

Front

Blood Moon Noun

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[bluhd moon]

Back

Blood Moon

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The reddish appearance of the Moon during a total lunar eclipse, caused by sunlight refracting through Earth's atmosphere.

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Example: This diagram shows how a Blood Moon occurs during a total lunar eclipse, when the Earth blocks direct sunlight and the Moon passes through its darkest shadow (umbra).

Front

Refracted Adjective

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[ri-frakt-ed]

Back

Refracted

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Describing the change in direction of a light ray as it passes from one medium to another, such as atmosphere.

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Example: This diagram shows a ray of light bending, or refracting, as it passes from one material into another, which changes its direction of travel.

Front

Opaque Adjective

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[oh-peyk]

Back

Opaque

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Describing an object that is not transparent, completely blocking light from passing through it and thereby forming a shadow.

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Example: An opaque object blocks light from a light source, preventing it from passing through and causing a shadow to form on the other side.