Interactions of the Earth, Moon, and Sun: Tutorial

How does your model support the claim that the Northern and Southern Hemispheres have different seasons?

The model shows that Earth is tilted on its axis. Because of this tilted axis, the Sun's rays hit different parts of the planet with different intensities during its orbit. The axis always points in the same direction. When a hemisphere inclines toward the Sun, it receives more direct sunlight than the hemisphere inclined away from the Sun. This causes the Northern Hemisphere and the Southern Hemisphere to experience different seasons at the same time of the year.

What are the strengths and limitations of your model?

The strength of this model is that it clearly shows the tilt of the Earth, which is the reason for the different seasons. The limitations of this model are that because it is not drawn to scale, it does not show an elliptical orbit or the actual distance between the Sun and Earth. This model also does not show the angle of the Sun's rays nor the intensity.

What are the strengths and limitations of this model?

the strength of this model is that it shows the positions of the Sun, the Moon, and Earth during a solar eclipse along with the orbits of Earth and the Moon. The limitations of the model are that since it is not to scale, it does not show what the Sun looks like from Earth during an eclipse. It doesn't represent the tilted orbit of the Moon either.

When it's summer in the Northern Hemisphere, what season is it in the Southern Hemisphere? autumn spring summer winter

winter

Explain why a solar eclipse occurs only during a new Moon.

A solar eclipse only occurs during a new Moon because the Moon needs to be between Earth and the Sun. This occurs only during a new Moon.

What are the strengths and limitations of the model?

A strength of the model is that it shows the angle of the Sun's rays on the Northern and Southern Hemispheres. Limitations of the model are that it is not drawn to scale and it does not show Earth's orbit. Also, some people might mistakenly think that the tilt of Earth's axis changes with the seasons, but it doesn't.

A friend claims that the change of seasons arises completely from Earth's distance from the Sun because Earth's orbit is elliptical. At its closest, Earth is about 147 million kilometers from the Sun. At its farthest, the distance is 152 million kilometers. Do you agree with the friend's claim? Use your model to support or disprove this statement.

Earth does have an elliptical orbit, but the path is nearly circular based on the distances given. The model shows that Earth's axis is tilted. During summer in the Northern Hemisphere, the hemisphere tilts toward the Sun. The Southern Hemisphere experiences winter at that time, because it points away from the Sun.

On average, there are two lunar eclipses every year. However, the Moon goes through a complete orbit every 27 days. Does your model show why this occurs? Explain your answer.

Lunar eclipses do not occur at every full Moon due to the orbital tilt of the Moon in relation to Earth's axial tilt, which is not shown in the model.

Which model shows an equinox, and which shows a solstice? Explain your reasoning.

Model A shows an equinox because the Sun's rays appear to hit the equator directly. Model B shows a solstice because the Sun's rays hit Earth at a slight angle.

Can a lunar eclipse happen during any phase of the Moon? Use the model to explain your answer

No. A lunar eclipse can occur only during a full Moon. As the model shows, the Sun must be shining directly on the side of the Moon that faces Earth for a lunar eclipse to occur, which is why lunar eclipses only occur during a full Moon.

A student claims that model A shows winter in both hemispheres. Do you agree? Explain why or why not.

No. Since Model A shows an equinox, it shows that it is spring in one hemisphere and fall in the other hemisphere.

When you look at the night sky, sometimes there is a full Moon and sometimes the Moon looks like it's barely there. Why does this happen?

The Moon orbits Earth. The phases of the Moon change depending on the Moon's position relative to the Sun and Earth. The phases represent sunlight reflecting off the Moon as seen from Earth.

What will the Moon look like from Earth when it is in the position shown in your model? Explain your answer.

The Moon will look red in Earth's shadow. That's because the Sun's light is refracted by Earth's atmosphere.

Which seasons are shown in model B for the Northern and Southern Hemispheres? Explain your answer.

The Northern Hemisphere is pointing toward the Sun, so it is summer in the Northern Hemisphere. The Southern Hemisphere is pointed away from the Sun, so it is winter in the Southern Hemisphere.

How does the Moon affect Earth? Describe two examples.

The gravitational pull of the Moon influences tides. It also affects Earth's rotation, which determines the length of day and night.

True or false? A lunar eclipse occurs when the Moon is between the Sun and Earth.

This statement is false. A lunar eclipse occurs when Earth is between the Sun and the Moon.