Astronomy: Eclipses: Solar, Lunar, and Geometry
Exploring how the Sun, Earth, and Moon line up
Astronomy: Eclipses: Solar, Lunar, and Geometry
Exploring how the Sun, Earth, and Moon line up
Astronomy - Grade 6-8
- 1
In a solar eclipse, what is the order of the Sun, Moon, and Earth in space? Explain which object casts a shadow and which object receives the shadow.
A solar eclipse happens when the Moon blocks sunlight from reaching part of Earth.
In a solar eclipse, the order is Sun, Moon, Earth. The Moon casts a shadow, and Earth receives the shadow. - 2
In a lunar eclipse, what is the order of the Sun, Earth, and Moon in space? Explain which object casts a shadow and which object passes through the shadow.
In a lunar eclipse, the order is Sun, Earth, Moon. Earth casts a shadow, and the Moon passes through Earth's shadow. - 3
A student says, "A lunar eclipse happens when the Moon blocks the Sun from Earth." Explain why this statement is incorrect.
Look for the object that is in the middle.
The statement is incorrect because it describes a solar eclipse. A lunar eclipse happens when Earth blocks sunlight from reaching the Moon and the Moon moves through Earth's shadow. - 4
Draw or describe the umbra and penumbra of a shadow. How are they different?
Think about the darkest part and the fuzzy lighter edge of a shadow.
The umbra is the darkest central part of a shadow where the light source is completely blocked. The penumbra is the lighter outer part of a shadow where the light source is only partly blocked. - 5
During a total solar eclipse, an observer stands in the Moon's umbra on Earth. What does the observer see, and why?
The observer sees the Sun completely covered by the Moon because the observer is in the darkest part of the Moon's shadow, where the Moon blocks the Sun's disk. - 6
During a partial solar eclipse, an observer stands in the Moon's penumbra on Earth. What does the observer see, and why?
Partial means not completely covered.
The observer sees only part of the Sun covered by the Moon because the observer is in the Moon's penumbra, where the Moon blocks only part of the sunlight. - 7
Why does a solar eclipse not happen at every new moon, even though the Moon is between the Sun and Earth at new moon?
The Moon's orbit is not in the exact same flat plane as Earth's orbit.
A solar eclipse does not happen at every new moon because the Moon's orbit is tilted compared with Earth's orbit around the Sun. Most new moons pass slightly above or below the Sun from our point of view, so the shadows do not line up with Earth. - 8
Why does a lunar eclipse not happen at every full moon, even though Earth is between the Sun and Moon at full moon?
A lunar eclipse does not happen at every full moon because the Moon's orbit is tilted. Most full moons pass above or below Earth's shadow instead of moving through it. - 9
A diagram shows the Sun, Earth, and Moon almost in a straight line. The Moon is on the opposite side of Earth from the Sun, but it passes only through Earth's penumbra. What type of eclipse is this, and what would the Moon look like?
Use the shadow region named in the question.
This is a penumbral lunar eclipse. The Moon would look only slightly dimmer because it passes through the lighter outer part of Earth's shadow. - 10
The Moon's average distance from Earth is about 384,000 kilometers. During some solar eclipses, the Moon appears slightly too small to cover the Sun completely. What type of solar eclipse can happen then, and what would observers see?
An annular solar eclipse can happen when the Moon appears too small to cover the Sun completely. Observers in the main path see a bright ring of the Sun around the Moon. - 11
A scale model uses a lamp as the Sun, a basketball as Earth, and a tennis ball as the Moon. To model a lunar eclipse, where should the tennis ball be placed?
For a lunar eclipse, Earth is between the Sun and the Moon.
To model a lunar eclipse, the tennis ball should be placed on the opposite side of the basketball from the lamp, in the basketball's shadow. - 12
Explain why eclipse shadows make narrow paths on Earth during solar eclipses but can cover the whole Moon during lunar eclipses.
During a solar eclipse, the Moon's umbra is small when it reaches Earth, so it makes a narrow path across Earth's surface. During a lunar eclipse, Earth's shadow is much larger than the Moon, so the whole Moon can fit inside Earth's umbra.