11Volcano Toba
![Volcano Toba](https://i0.wp.com/factrepublic.com/wp-content/uploads/2019/04/20.Volcano-Toba.jpg)
Around 70,000 years ago the Volcano Toba in Indonesia erupted and covered the earth with so much ash the sun was dimmed for 6 years. The population of early humans neared extinction and some studies indicate there were as few as 40 breeding pairs.
12Cambrian Explosion
![Cambrian Explosion](https://i0.wp.com/factrepublic.com/wp-content/uploads/2019/04/21.Cambrian-Explosion.jpg)
The Cambrian Explosion might be explained by rising sea levels 540 million years ago which resulted in three times as much calcium being dissolved into the sea. Life forms had to create shells, bones and other hard tissues in response leading to the diversity of life we see today.
13Cretaceous period
![Cretaceous period](https://i0.wp.com/factrepublic.com/wp-content/uploads/2019/04/22.Cretaceous-period.jpg)
During the Cretaceous period (145 - 100 million years ago), Earth's climate was so warm that there were no polar ice caps, and forests probably extended all the way to the South Pole. Local plants and dinosaurs evolved to live in continuous sunlight in the summer and darkness in the winter.
14Australopithecus
![Australopithecus](https://i0.wp.com/factrepublic.com/wp-content/uploads/2019/04/23.Australopithecus.jpg)
Australopithecus, anatomically similar to modern humans, co-existed with Megalodon, the biggest shark species that ever lived.
15Homo erectus
![Homo erectus](https://i0.wp.com/factrepublic.com/wp-content/uploads/2019/04/24.Homo-erectus.jpg)
Ancient human ancestor Homo erectus ate cooked food as long ago as 1.9 million years.
16Ice age
![Ice age](https://i0.wp.com/factrepublic.com/wp-content/uploads/2019/04/25.Ice-age.jpg)
The Earth is currently and has been in an ice age for over 30 million years, the Late Cenozoic Ice Age.
17Robert Ballard
![Robert Ballard](https://i0.wp.com/factrepublic.com/wp-content/uploads/2019/04/1.Robert-Ballard.jpg)
When Robert Ballard (professor of oceanography) announced a mission to find the Titanic, it was really secret a cover story for a classified mission to search for lost nuclear submarines. They finished before they were due back, so the team spent the extra time looking for the Titanic and actually found it.