Do Our Oceans Feel the Tug of Mars?

Well into the space age, our thinking about the heavens is still entangled with ideas from ancient Greece. Like the classical Greek cosmologists, we tend to envision the heavenly realm as a place of order and harmony, with planets and moons in elegant, unchanging orbits.

As Johannes Kepler and Isaac Newton later showed, this is true in approximation. But in detail, the motions of the planets are messy and erratic. Like the squabbling gods the Greeks once imagined them to be, the planets tease and tug at each other, and these gravitational provocations cause them to tilt, wobble, and nod as they circle the sun. While science has abandoned the Greek belief in astrology—the idea that celestial bodies govern human destinies—the Earth as a whole really does feel the pull of other planets. In fact, the heavens may be responsible for some of Earth’s more unruly behaviors and even what we, after the