Pave New Worlds

The extra-solar planet count is more than 400 and rising. Before long we may find an Earth-like planet around another star. If we do, and can visit, what next? Stake out our claim on an alien world or tread lightly and preserve it? We´ll look at what our record on Earth says about our planet stewardship. Also, whether a massive technological fix can get us out of our climate mess. Plus, what we can learn about extreme climate from our neighbors in the solar system, Venus and Mars.