We, the inhabitants of this world we call Earth, have tended to think of our little planet as being rather special. It is the only one, or at least the only one that we know of, that harbors life.
This is particularly special for me as a Biologist. Biology is the study of life. As such, I would be unemployable on any other planet. And, well, also likely dead. But, I digress…
At a recent conference, a scientist who is part of NASA’s Kepler scientific team announced they had discovered many earth-like bodies in outer space. In fact, of the planets now discovered, planets that are earth-like dominate in terms of number. There are more earth-like planets than any other planets.
What might it mean? Well, so far, no one knows. The earth-like planets are simply those that are nearly the same size as earth. That is the point of the Kepler satellite mission. To map the galaxies, using size as first cut for determining which planets might be like our own little rocky planet, and might be habitable, or even inhabited. The Kepler satellite is looking specifically for earth-sized planets orbiting a star, just as we orbit our sun.
But, finding earth-sized planets, in and of itself, is a pretty amazing finding. These apparently litter the Milky Way. And, until now, most of the new planets that have been discovered are more like the gas giants, like Jupiter and Neptune.
The fact that we are a little rocky planet, by comparison, is actually pretty important, and pretty fundamental in the maintenance of life. Our planet has a surface that we can live on. We are the only planet with liquid water. And, we have an atmosphere that facilitates temperature and moisture regimes that we can tolerate. These things are not possible on large, gassy planets. So, it helps that these potential planets are earth-like in size.
However, we do not yet know if they are rocky. Nor do we know if they are orbiting too close to, or too far from, their suns to maintain suitable temperatures. We do not know if they have water, or any sort of atmosphere.
But, at least there is exciting new potential. Kepler scientists recently revealed that there might be more than 700 earth-like planets out there orbiting another star.