What If The Earth Had Two Moons?

  But how would a second moon affect the ocean tides? Would months on Earth become longer or shorter? And would these two satellites inevitably collide to cause a...

What If Earth Froze Overnight?

Overnight, our planet has gone from a pale blue dot to a glistening white snowglobe. Stretches of Earth have become frozen wastelands that are completely inhospitable...

What If the Gulf Stream Stopped?

Our planet has seen this before. Its ice has already melted. Water levels have risen. Ocean currents have already stopped. The last time this happened was 13,000 years...