Assessment Questions 1.12

1. What historical celestial impact event is famously known for causing a massive extinction, and what were the consequences of this impact?

The collision of a 10-kilometer wide asteroid about 65 million years ago caused a massive extinction event, including the wiping out of dinosaurs. It left a 180-kilometer wide crater near the Yucatan Peninsula.

2. Provide examples of smaller-scale celestial impact events on Earth, including the Barringer Meteor Crater and the Tunguska event.

The Barringer Meteor Crater in Arizona resulted from a meteorite impact about 50,000 years ago. The Tunguska event involved a comet exploding over Siberia, causing devastation in a circular area without a crater.

3. What is the Younger Dryas, and what extraterrestrial impact hypothesis has been suggested to explain it?

The Younger Dryas is a period of sudden temperature decline around 12,800 to 11,700 years ago. Some scientists suggest an extraterrestrial impact as its cause, though skepticism remains due to the absence of a crater and inconclusive evidence for extensive fires.