Howard Smith, a senior astrophysicist at Harvard, made the claim that we are alone in the universe after an analysis of the 500 planets discovered so far showed all were hostile to life. Dr Smith said the extreme conditions found so far on planets discovered outside out Solar System are likely to be the norm, and that the hospitable conditions on Earth could be unique. “We have found that most other planets and solar systems are wildly different from our own. They are very hostile to life as we know it,” he said. He pointed to stars such as HD10180,...