Eclipses

Eclipses

Middle School

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Learning Objectives

• Define the terms eclipse, umbra, and penumbra.

• Describe the alignment and moon phase for solar and lunar eclipses.

• Explain why eclipses do not happen every month.

• Identify the safety precautions for viewing a solar eclipse.

Key Vocabulary

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Eclipse

An event where one celestial body moves into another's shadow, which blocks its light from view.

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Solar Eclipse

This occurs when the Moon passes between the Sun and Earth, casting a shadow on our planet.

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Lunar Eclipse

This happens when Earth passes directly between the Sun and Moon, casting a shadow on the Moon.

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Umbra

The umbra is the darkest, central part of a shadow where the light source is completely blocked.

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Penumbra

The penumbra is the lighter, outer part of a shadow, where the light is only partially blocked.

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What is an Eclipse?

Types of Eclipses

• An eclipse happens when one celestial body moves into the shadow of another celestial body.

• From Earth, we can see two types: solar eclipses and lunar eclipses.

• These events are all about the alignment of the Sun, the Earth, and the Moon.

Parts of a Shadow

• The umbra is the dark, central core of a shadow where light is completely blocked.

• The penumbra is the lighter, outer part of a shadow where light is partially blocked.

• The type of shadow you are in determines what you will see during the eclipse.

Multiple Choice

What is the name for the darkest, central part of a shadow cast during an eclipse?

• Umbra

• Penumbra

• Eclipse

• Ray

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What is a Solar Eclipse?

• A solar eclipse occurs when the Moon passes between the Sun and Earth.

• This alignment casts the Moon's shadow on Earth during the New Moon phase.

• A total eclipse blocks the Sun completely; a partial eclipse blocks it partly.

• WARNING: Never look directly at the sun; it can cause permanent eye damage.

Multiple Choice

During which moon phase can a solar eclipse occur?

• New Moon

• Full Moon

• First Quarter

• Third Quarter

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Understanding Lunar Eclipses

• A lunar eclipse occurs when Earth is directly between the Sun and Moon.

• ​This alignment casts Earth’s shadow onto the Moon, blocking direct sunlight.

• During a total eclipse, the Moon can appear red, called a "blood moon".

• A partial eclipse happens when only part of the Moon is in shadow.

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Multiple Choice

What is the correct alignment for a lunar eclipse to occur?

• Sun - Earth - Moon

• Sun - Moon - Earth

• Earth - Sun - Moon

• Moon - Earth - Sun

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Why Don't Eclipses Happen Every Month?

• The Moon orbits Earth monthly, but eclipses don’t happen that often.

• The Moon’s orbit is tilted at about a 5-degree angle.

• This tilt causes the Moon to pass above or below Earth’s shadow.

• Eclipses only occur when the Sun, Earth, and Moon align perfectly.

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Multiple Choice

What is the primary reason that eclipses do not occur every month?

• The Moon's orbit is tilted.

• The Earth is tilted on its axis.

• The Moon orbits too quickly.

• The Sun is too far away.

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Common Misconceptions

Misconception	Correction
A solar eclipse happens every New Moon.	Eclipses are rare because the Moon's orbit is tilted.
It is safe to glance at a solar eclipse.	Never look at a solar eclipse without special eye protection.
Solar and lunar eclipses have the same alignment.	Solar: Sun-Moon-Earth. Lunar: Sun-Earth-Moon.

Multiple Choice

How does the position of the Earth and Moon differ between a solar eclipse and a lunar eclipse?

• In a solar eclipse, the Moon is between the Sun and Earth; in a lunar eclipse, the Earth is between the Sun and Moon.

• In a solar eclipse, the Earth is between the Sun and Moon; in a lunar eclipse, the Moon is between the Sun and Earth.

• In a solar eclipse, the Sun is between the Earth and Moon; in a lunar eclipse, the Earth is between the Sun and Moon.

• Both eclipses have the same alignment but happen at different times of the year.

Multiple Choice

Why does an observer in the umbra see a total solar eclipse, while an observer in the penumbra sees only a partial eclipse?

• The umbra is the dark central shadow where the Sun is completely blocked, while the penumbra is a lighter shadow where it's only partially blocked.

• The umbra is larger than the penumbra, so it covers more of the Sun.

• The penumbra is the shadow that causes a lunar eclipse, not a solar one.

• The umbra only exists during a new moon, while the penumbra exists during all phases.

Multiple Choice

If the Moon's orbit was not tilted, what would be the most likely outcome?

• We would experience a solar eclipse every new moon and a lunar eclipse every full moon.

• We would never have eclipses.

• We would only have lunar eclipses.

• We would only have solar eclipses.

Multiple Choice

An observer on Earth notices the sky getting dark in the middle of the day as the Moon perfectly blocks the Sun. Analyze this event.

• It's a total solar eclipse, the phase is a new moon, and the observer is in the Moon's umbra.

• It's a total lunar eclipse, the phase is a full moon, and the observer is in Earth's umbra.

• It's a partial solar eclipse, the phase is a new moon, and the observer is in the Moon's penumbra.

• It's an annular eclipse, the phase is a third quarter moon, and the observer is in the antumbra.

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Summary

• A solar eclipse occurs at a New Moon in a Sun-Moon-Earth alignment.

• A lunar eclipse occurs at a Full Moon in a Sun-Earth-Moon alignment.

• The umbra is the full, dark shadow; the penumbra is the partial, lighter shadow.

• Eclipses are rare due to the Moon's 5° orbital tilt. Use eye protection for solar eclipses.

Poll

On a scale of 1-4, how confident are you about the concepts covered in today's review?

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