A New Earth?

A recent study using a computer simulation program modeling planetary formation suggests Earth might have a neighbor similar to itself orbiting in the habitable zone of Alpha Centauri B, one of the stars in the Alpha Centauri multiple star system that is the closest stellar neighbor to the Sun. Alpha Centauri B is a Sun-like star right down to its high metals content. That's important because it suggests there might be rocky, metal-rich planets, like Earth, in orbits that could support life. The Sun's habitable zone, for example, has Venus on its inner edge, Earth in the middle, and Mars on the outer edge.

If Nature goes along with the computer simulation, it could give the collective space efforts of humanity a compelling long term objective that would structure shorter terms plans. Settling Earth's Moon would then be about establishing the beginning of an economy that includes off-world resources. Settling Mars would be about expanding that economy, creating an outpost at the inner edge of the resource-rich Main Belt of asteroids, and becoming a spacefaring civilization. From that base, perhaps a couple centuries down the road, humans might be in a position to undertake an interstellar journey to a new Earth.

Long before that, of course, we would learn a lor about that planet. NASA missions scheduled for launch within the next few years will be able to determine whether the simulation is correct. If it is, telescopes coming online soon will be able to give us more information-- including whether the planet might be inhabited. The Alpha Centauri system is a bit more than four light-years away, which makes an interstellar flight by humans at least conceivable. That distance might also allow us to launch an unmanned interstellar probe yet this century.

The possibilities are enormous-- and exciting.