Challenge: WebQuest

Life on Earth (Xtreme Files) http://astrobio.terc.edu/xtreme

Activity 1: Timeline of Life on Earth
Activity 2: Origins: The Beginning of Life
Activity 3: Oxygen Changes Everything
Activity 4: Impacts and Extinction

Science on the Internet

Timeline of Life on Earth
The Cosmic Clock
PBS - A Brief History of Life
Evolutionary and Geological Timelines

Origin of Life on Earth
NOVA - How Did Life Begin?
NASA Origin of Life on Earth Concept Map
Windows to the Universe - Origins of Life on Earth

Meteor Impacts
Earth Impact Database
Meteor Impacts: Life's Jumpstarter?
Terrestrial Impact Craters