Given that “Spaceman,†the terrifically danceable new single from the Killers’ forthcoming Day and Age, is not only about being abducted by aliens, but follows “Human,†the album’s terrifically danceable first single, which is about people becoming party robots, it’s fair to wonder whether front man Brandon Flowers is indeed from another planet. It’s not even how his lyrics (like “hesitation to this life I giveâ€) imply unfamiliarity with normal speech, or that his apparel (like ostrich-feather epaulets and riverboat-gambler neckties) suggests Martian military uniforms. It’s how damn well he can write a song, whether channeling Bruce Springsteen (“When We Were Young,†in 2006) or some sort of Terminator dandy (now). This one will lodge itself so deep in your brain you’d think it was inserted there by an alien probe.