Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
12 Cards in this Set
- Front
- Back
|
Astronomy |
The study of the moon, stars and other objects in space. |
|
|
axis |
An imaginary line that passes through the Earth's center and the North and South Poles. |
|
|
rotation |
The spinning of earth on its axis. Causes day/night. One full rotation equals one day. |
|
|
revolution |
The movement of one object around another object. Earth revolves around the sun. One full revolution equals one year. |
|
|
orbit |
The path of an object as it revolves around another object in space. Earth's orbit around the sun is elliptical. |
|
|
equinox |
When the noon sun is directly over the equator, and day/night are the same length. vernal equinox - spring autumnal equinox - fall |
|
|
solstice |
When the sun appears farthest north or south of the equator. Summer solstice (Northern Hemisphere)- June 21 - longest day of the year Winter solstice (Northern Hemisphere) - December 21 - shortest day of the year |
|
|
Why do we have seasons? |
Because earth is tilted on its axis as it revolves around the sun. |
|
|
Exact tilt of the Earth's axis: |
23.5 degrees from the vertical |
|
|
inertia |
The tendency of an object to resist a change in motion. |
|
|
gravity |
The force that attracts all objects to each other. |
|
|
What keeps earth in orbit around the sun? |
Inertia and gravity. |
