1. Why does Earth seem to be standing still?
Because you move along with it.
Earth moves slowly and steadily.

2. What are 2 clues that Earth moves?
Stars seem to move across the sky.
The seasons change.
Seasons change during the year because Earth is tilted on its axis and it orbits the sun.

3. What causes day and night?
When a place on Earth is turned toward the sun it is day.
When a place on Earth is turned away from the sun it is night.
Earth rotates from west to east.

4. Earth’s Revolution A complete trip around the sun is one revolution.
Earth takes 1 year or about 365 days to complete one revolution.
As Earth orbits the sun, its distance from the sun changes.
Gravity between the Sun and Earth keeps Earth revolving.
Without gravity, Earth would fly off into space.

5. Why is it summer in the Northern Hemisphere when it is winter in the Southern Hemisphere?
During summer in the Northern Hemisphere, the North Pole is tilted toward the sun and gets more direct sunlight, while the South Pole tilts away from the sun and gets less direct sunlight.

6. What causes Earth’s seasons?
Earth’s axis is tilted so that the end tilting toward the sun has Spring and Summer. The end tilted away from the sun has Winter and Fall.
Earth revolves around the sun resulting in Earth’s axis being tilted toward the sun 1/2 the year and away from the sun the other ½ of the year.

7. Moon Phases
The changing phases of the Moon depend upon the positions of the Sun, Moon, and Stars.
The Moon rotates once on its axis at about the same rate that it revolves once around Earth.
Different amounts of the lighted half of the Moon facing the Earth causes the apparent changes of the Moon’s shape.

8. Eclipses
An eclipse occurs when one object in space comes between the Sun and another object.
Lunar and solar eclipses can be seen from Earth.
A solar eclipse occurs when the Moon, Sun, and Earth are in-line with each other.
In a lunar eclipse the Moon passes through Earth’s shadow.

9. Stars The Sun is a medium-sized star close to the Earth.
All stars, including the Sun, are hot balls of gas.
Apparent patterns of stars are called constellations.
Distance between the stars seem close together, but they are actually far apart.

10. Essay
What causes the phases of the Moon to change in the same pattern approximately every 29 days?
As the Moon revolves around Earth, different parts of the Moon are struck by sunlight, which then reflects off of the Moon’s surface. As different parts of the Moon’s surface are struck by sunlight, different phases of the Moon can be seen.