Jack describes the ancient climate shift known as the Younger Dryas. He states that, as the world was coming out of the last glacial period, melting ice sheets added so much freshwater to the Atlantic Ocean that certain ocean circulation patterns shut down. Since thermohaline circulation is a major source of heat for the surfaces of continents, the globe was plunged back into an ice age.
From its blood-like hue to its potential to sustain life, Mars has intrigued humankind for thousands of years. Learn how the red planet formed from gas and dust and what its polar ice caps mean for life as we know it.