A new study indicates that earthlike planets (rocky planets with large oceans) may be far more common than previously thought.

Some points from the CNN story:

Earthlike planets covered with deep oceans that could harbor life may be found in as many as a third of solar systems discovered outside of our own, U.S. researchers said on Thursday.

This would seem to indicate that there are literally millions of such planets in our galaxy. Perhaps tens or hundreds of millions.

“We now think there is a new class of ocean-covered, and possibly habitable, planets in solar systems unlike our own,” [researcher Sean] Raymond said in a statement.

What he’s referring to is that computer modelling of solar systems with large gas giants close to their sun (”Hot Jupiters”) seem to create gravitational eddies that encourage the formation of smaller rocky planets. The large gravitational fields of these “hot Jupiters” also tend to pull in large numbers of icy bodies such as comets and planetoids which provide the water needed for oceans to exist on the rocky planets. It’s plausible.

But I am skeptical of computer models. I think computer modeling of relatively simple systems like solar system formation are probably fairly reliable, especially when compared to computer modeling of mind-numbingly complex systems such as global climate, but even so I go back to chaos theory and its fundamental premise that chaotic systems are “sensitive to initial conditions” and I doubt even our solar system models are accurate yet.

However, I have always believed that earthlike, rocky, water-rich planets are common in the universe, in the galaxy, and even in our neighborhood.

One reason I think that planets such as earth are common that I have yet to see picked up on by the astronomical community is that these “hot Jupiters” probably have “moons” that are planet-sized. Those moons could be quite Earthlike if Titan is any indication.

Still, this is an encouraging development. Astronomers have always been notorious for being cautious about things, so this group must be pretty confident in their simulations to make such an announcement.