Evidence that Earth was hit by two solar storms - 10 times larger than those observed recently - 1,000 years ago. If they occurred today, they'd have devastating effects on power supplies, satellites and communications.
New evidence suggests that life on Earth began 300 million years earlier than previously documented, pushing the origin of life close to when the planet formed.
Floods and landslides remain a risk from Patricia - strongest storm yet recorded in the Western Hemisphere. The storm caused less damage than expected. It went from a tropical storm to a Category 5 hurricane in just 24 hours.