Why Not Mars
Maciej Cegłowski has made a persuasive case against human boots on Mars in the foreseeable future. Not only am I convinced that he's right in specific case, but ever since reading Kim Stanley Robinson's Aurora a few years ago, I've largely divorced myself from the romantic falsehood of galactic manifest destiny. Let's just build more telescopes and robots while we work on fixing up where we are always, always, always going to live.