An anonymous reader writes "Space.com has an article on how old rocket stages are carrying bacteria from Earth to interstellar space. For example, four upper rocket stages were used to boost deep space probes Voyager 1, Voyager 2, Pioneer 10 and New Horizons. The spacecraft were sterilized, but the rocket stages were not, and they now carry the bacteria of the engineers who handled them. If the rocket stages hit a habitable planet, and the bacteria survive the journey, they would be able to reproduce and colonize the planet ... not that there's a high liklihood of that. 'In 40,000 years, this wayward 185-pound (84 kilogram) lump of metal will pass by the star AC+79 3888 at a distance of 1.64 light-years. ... Given the sheer expanse of time that lies ahead of the four discarded rockets, at least one is likely to eventually encounter a planet. But even if that planet's environment is conducive to life, the long dormant bacteria will not just gently plop into some exotic ocean. No soft landing can be expected.'"