Water Worlds

The hunt for Earth-like planets continues! This fascinating article I came across discusses how scientists are focusing their search for life on planets that, like ours, happen to be close enough to their sun that liquid water can form.  

But now, based on computer simulations at Harvard University, scientists are beginning to realize that some of those planets may be almost all water and no land.

These so-called “water worlds” would form as ice balls out in the remote regions of a solar system and then migrate inward to the so-called “goldilocks zone” nearer to the sun, where the ice would melt and the surface of the planet would be entirely water.  

And not just the surface – these planets would be 25-50% composed of water, compared with the roughly 0.025% total mass of Earth.  The water on these worlds would extend thousands of kilometers deep, deep enough that the water at the bottom would be compressed into high-pressure phases of ice, becoming similar to the hot and hard silicate rocks located deep within the Earth’s mantle.

So far, no water worlds have been definitively identified around nearby stars.  But certain planets with low density compared to Earth are considered to be candidates.

Anyone else feeling really small all of a sudden?