If I tell you to imagine a habitable planet, you might end up with an Earth-like planet where ocean and land exist in a perfect balance. However, things are quite different in real life. Fergus Simpson, a researcher from the Institute of Cosmos Science at the University of Barcelona has published a study, which suggests that most habitable planets are submerged in water. Using computer simulations accounting for enormous factors in a planet, such as erosion and the deep water cycle, he found that most of those habitable planets (at least simulated ones) have less than 10 percent land, which is even less than Earth’s 29 percent.
The result shows planets with less amount of water inclined to be dominated by land, where most of the habitable planets are almost water worlds. Even our planet Earth would be covered in water if it had shallower oceans and weaker gravity.
Rare and perfect
According to Simpson’s study, this could be the fate of most habitable worlds. However, our own planet seems to be a rare example thanks to its right amount of water and surface features, which made it a perfect balance.
Not everyone agrees with Simpson, there are some who are skeptical about his study. One of them is astrophysicist Sean N. Raymond.
“I’m a bit puzzled about this paper,” Raymond, warns Gizmodo. “I find studies that extrapolate from N=1 to be interesting but hard to interpret. In this case, there are plenty of unanswered—but relevant questions.”
However, Simpson assured that his new water world theory is testable. Also, future instruments such as James Webb Space Telescope will provide us detailed information. Measuring the atmospheric conditions of alien planets, it will give us information on how much water might be on the surface. This study is at least a reminder that having plenty of water doesn’t make a planet human-friendly.