/sci/ - Science & Math

>In our research, for example, we have modeled planets with a composition similar to Earth's. We found that such planets, even when they are substantially more massive than our world, should be geophysically active and have atmospheres and climates that might be friendly to life. In fact, we have learned that Earth's mass may be at the lower extreme of the range needed for a planet to be habitable. In other words, had Earth been any smaller, it might have turned out to be as lifeless as Mars and Venus seem to be.
Dimitar D. Sasselov and Diana Valencia, "Planets We Could Call Home", Scientific American, August 2010

Here is a thought. Perhaps we aren't the first intelligent species to evolve in our galaxy, but all previous species have evolved on worlds too large to escape its gravity and colonize space. Perhaps it was just too costly for them and they were wiped out before they got around to putting in sufficient resources.

Humanity, thanks to our relatively small home planet, might end up being the first species to colonize the galaxy.