In a new study, researchers found that during epochs of extreme heat -- 20 to 30 degrees Fahrenheit hotter than today -- Earth may have experienced cycles of dryness followed by massive rain storms hundreds of miles wide that could dump more than a foot of rain in a matter of hours. The research not only sheds light on Earth's distant past and far-flung future but may also help to understand the climates of exoplanets orbiting distant stars.