P2gThreats to Earth

P2g Threats to Earth

Using pages 63-65 in your textbooks and on the web:http://www.jpl.nasa.gov/multimedia/neo/index.cfm

P2g Threats to Earth Answer these questions:

• Asteroids a) What are asteroids?b) Where are they found?

2. Past Collisions a) How do we know objects have hit Earth in the past?

b) When was the last major collision?

c) What evidence is there for this?

3. NEOs a) What are NEOs? b) How do astronomers track

them and why?

Comets

What are comets?

What are Comets?

• Comets are lumps of ______ and ______ orbiting the _____

• They were formed at the same time as our _______ ______

The Orbit of a Comet