We keep going back in time for these col­umns, but, for a change, let&rsquos take a peek into the future. After all, time travel occurs both ways So, let&rsquos go to a time, say, 200 years into the future, by when, if we haven&rsquot totally wrecked our planet and if our species has managed to survive, we may be vacationing among the stars, firing up the FTL Drives, and jumping light years to visit earth-like planets. What would that be like NASA&rsquos Jet Propul­sion Laboratory, which is about as good at putting ships in space as marketing itself, has recently come up with a set of three beautiful, retro-looking posters (think sci-fi book covers from the 1950s) for space travel. Its focus A gaggle of &lsquoexoplanets&rsquo that were spotted earlier this year by NASA&rsquos Kepler space tele­scope, in star-systems hundreds of light years from our own, with as many as ten of them deemed to have several features (being rocky, having a similar mass, orbiting stars similar to our sun, at a similar distance) that made them very earth-like.