Last week we had the exciting discovery of a a solar system very similar to our own:

Two planets much like Saturn and Jupiter are orbiting a star roughly half the size of our sun in a solar system some 5,000 light years away, astronomers say.

The newly discovered complex seems like a parallel star system to the one that includes Earth, researchers say. Both planets are composed largely of gas and each is a bit smaller than its counterpart in our solar system. The smaller planet is about twice the distance from its star as the larger one, just as Saturn is roughly twice as far from the sun as Jupiter.

That's cool, but what we want to find is not so much a solar system like ours as a planet like ours. For that, it turns out that we might have to look as far as we once thought:

A Second Earth in Our Solar System

Traveling to another Earth-like world just got a lot easier. It turns out that there may be many other dirt-and-water planets lurking at the edges of our solar system in places like the Oort Cloud. These planets, which could be roughly the size of our own, would contain all the elements we need for life. They're just sitting in a cold, dimly-lit part of the solar system, waiting to be defrosted and colonized. Yesterday, NASA scientists announced that this changes the prognosis for nearby livable planets.

NASA's Alan Stern said these planets are so far away from the sun that we haven't seen them yet:

Stern says:

Our old view, that the Solar System had nine planets will be supplanted by a view that there are hundreds if not thousands of planets in our Solar System. It could be that there are objects of Earth-mass in the Oort cloud (a band of debris surrounding our planetary system) but they would be frozen at these distances. They would look like a frozen Earth.

Still, it might be something of a stretch to describe these planets as "livable." They're going to be darn cold. However, we ought to be able to think of ways to warm and brighten them up -- maybe by moving them closer to the sun?