We learned this week of the existence of a planet, Ross 128 b, which has roughly the same mass and surface temperature as Earth. It orbits a relatively stable red-dwarf star and—best news of all—it appears to be well-suited to the accumulation of surface water and thus to mammalian habitability. The downside? Ross 128 b is presently 11 light-years away, which is almost three times as far from us as our better known Earth-like twin, Proxima b. But here's the really good news. The solar system containing Ross 128 b is getting closer to our own. In a mere 79,000 years, it should be within, say, 40-trillion km of us!
Critics will say that we should stop looking to the skies and focus on getting our own house in order. This is, without question, a very good point. Others will wax romantic about limitless human frontiers and our longing for interstellar exploration. Another excellent point. But here's the best reason of all to go. If we don't do it, squirrels will evolve higher intelligence and go without us.