Q&A: Should we seed life on alien worlds?

Astronomers have detected more than 3000 planets beyond our solar system, and just a couple weeks ago they discovered an Earth-like planet in the solar system next door. Most--if not all--of these worlds are unlikely to harbor life, but what if we put it there? In an essay published last month in Astrophysics and Space Science, theoretical physicist Claudius Gros of Goethe University Frankfurt in Germany suggests we do just that. His proposed Genesis Project would send artificially intelligent probes to lifeless worlds to seed them with microbes. Over millions of years, they might evolve into multicellular organisms, and, perhaps eventually, plants and animals.