1							2
					3											4
			5												6
		7
														8
	9								10
			11					12										13		14
15							16		17
				18
		19							20									21
		22											23
											24
						25				26
	27
									28

Across 3. An impact object on Earth is thought to have been responsible for the extinction of these animals. 6. the tail of a comet that is made of electrically charged particles 7. The Earth's ____________ acts like a shield, protecting us from many objects from space. 11. the color on the Torino Scale that is used for objects that most likely will hit Earth 12. a small body of ice, rock, and cosmic dust loosely packed together 13. another name for the cloud of dust and gas that surrounds the nucleus or "head" of the comet 15. country near the impact crater caused when the dinosaurs became extinct 17. the area between the orbits of Mars and Jupiter where most asteroids orbit 20. This is often the result when an object in space collides with another object in space. (2 words) 22. a small, rocky object that orbits the sun, usually between the orbits of Mars and Jupiter 26. the rating system that allows scientists rate the hazard level of objects moving toward Earth 27. The solid center of a comet 28. The _________ the number on the Torino scale, the more likely an object will collide with Earth.

Down 1. an area outside the orbit of Neptune where comets exist 2. a bright streak of light caused by a meteoroid entering Earth's atmosphere 4. one area scientists believe comets come from 5. when this enters our atmosphere it becomes a meteor 8. a meteoroid that reaches the Earth's surface 9. the number of major types of meteorites 10. this causes the ion tail of a comet to face away from the sun 14. when large numbers of meteors can be seen in the sky 16. The solar system is thought to be 4.6 _______ years old. 18. part of the comet that leaves behind debris that becomes meteoroids 19. The ion tail of a comet always faces ____________ from the sun. 21. Scientists believe impacts powerful enough to cause natural disasters happen on Earth every few ________ years. 23. the shape of the orbit of all objects travelling around the sun 24. a type of metal often found in meteorites 25. Most meteors do not reach Earth because they ____________ in our atmosphere