The recent discovery and analysis of a planet described as “something like our own Earth” highlights the point. This particular planet, with the colorful name GJ1214, is about six and half times more massive than Earth, with a larger diameter as well, and it measures three times less dense. Through a sophisticated series of observations and calculations, researchers determined that GJ1214 must be a “water world,” nearly 50 percent water by mass.
In other words, it has too much of a good thing. A planet with that much water is not a candidate for the support of advanced life, including humans. For a planet to have continents, nutrient recycling, and environments suitable for human habitation, its total water content must be no more than 0.05 percent, though some researchers would argue it must be even less.
Meanwhile, solar system modeling by a team of MIT researchers predicts that our own planet should contain about a thousand times more water than it does. So why is Earth’s water content so low—and at the just-right level for human life? Early in Earth’s history, an exquisitely orchestrated collision event blasted away the excess water and left behind exactly what we need (illustrated in the DVD Journey Toward Creation).
Next time you ride the waves, dive into a lake, paddle a stream, thrill at a gushing geyser, or take a long, cool drink from a fountain, don’t forget to thank God for the miracle of a planet with just enough, but not too much, water.