Outer Space

3. The Greenhouse _____________ is an increase in temperature caused when incoming solar radiation is passed but outgoing thermal radiation is blocked by the atmosphere.
4. The ________ planets are composed of rock and metal.
7. position
9. Meteoroid that reaches Earth’s surface without burning up completely.
11. Small icy bodies.
15. The length of time required for a planet to make one complete turn on its axis.
17. ________ planets are farthest from the sun and include: Jupiter, Saturn, Uranus, and Neptune.
18. Small rocky bodies.
19. The Astronomical ________ is the distance from the center of the Earth to the center of the Sun.
20. A __________ is a celestial body that orbits the sun and has a gravitational pull.
21. The Milky Way ________ contains our solar system.
22. The circular path a planet takes around the sun.
23. _________ is the force by which a planet or other body draws objects toward its center.

1. ________ planets are objects that are similar to planets except that they orbit the Sun in areas where there are many similar objects
2. The length of time required for a planet to make one complete trip around the Sun.
5. small, rocky body that travels through space
6. An asteroid ________ divides the Inner and Outer Planets.
8. The only place in our solar system, other than Earth, where humans have visited.
10. The solar system formed from a collapsing cloud of gas and dust called a _________.
12. ________ is defined as the ratio of the mass of an object to the volume of space the object takes up.
13. Bright streak of light that results when a meteoroid burns up in the Earth’s atmosphere-sometimes called a “shooting star”.
14. temperature
16. _______ planets are closest to the sun and include: Mercury, Venus, Earth, Mars.
23. The _______ planets are composed primarily of hydrogen and helium.