The solar system, filled with planets, moons, and asteroids, can be a turbulent place.  The numerous craters on the moon prove that collisions can and do happen.  Could a large scale impact happen on Earth?  Use the discussion questions below to explore the challenges of learning about asteroids and these events.   

• Describe the asteroid belt—where is it, and what is it composed of?  How did it form?
• Why is it so difficult to find craters on Earth, while on the Moon, they are so prevalent?
• Why are scientists tracking the paths of asteroids?  How?  What is the role of the network of observatories? 
• What can we learn about asteroids?
• What are some of the effects that might occur if a large meteorite were to hit the Earth?  What would be the changes in the local environment, and how might these affect life in the area?

When calculating probabilities for collisions in the cosmos, scientists must work on scales difficult to conceive.  To better understand the magnitude of astronomical distances, explore the points below. 

• When is an asteroid considered close to Earth?
• What is considered a high probablity of an asteroid colliding with Earth? 
• How is it that the probability of asteroids crossing Earth’s orbital plane can vary?
• Were an asteroid found that had a high probability of colliding with Earth, what precautions should be taken?