Gliese 581 C

Astronomers at the Geneva Observatory recently announced the discovery of what might be a terrestrial planet in around the star Gliese 581 in the constellation, While there’s still some debate about just how much solid ground there might be up there, it is interesting to see the progress we’ve made in our picture of the universe.

Four centuries ago, Galileo Galilei ran afoul of the Catholic Church for upholding the idea of a heliocentrism. We’ve since learned that even our Sun isn’t the center of the universe. It’s not even the center of our own galaxy for that matter. Now we’re closer to finding evidence that our solar system isn’t wholly unique in having terrestrial planets.

The discovery of a terrestrial planet in another solar system, some 20 light years away, fills in the edges of our biggest map in some very important ways. And it wasn’t all that long ago that we had a hard time getting a reliable map of someplace right here on Earth! (Really, not long ago at all. The last time I downloaded driving directions to somewhere… but I digress.)

Physicist Steven Hawking has said that in order to survive, the human species must go into space. Finding terrestrial planets outside our own solar system is certainly a step in the right direction, but we shouldn’t get too excited about looking for a westward passage to China just yet. In order to seriously explore the challenges of interstellar travel, we've got to establish a foothold in space right here in our own solar system.

It's also been said that if we can get into orbit, we're halfway to anywhere. In this case, I think the "we" is most important. We need established and functioning bases in orbit or on the moon, and we need to test our legs on Mars. By the time we get those things accomplished, planet hunting astronomers should have a pretty good selection of interstellar destinations to choose from.