Buzz Aldrin

The thing to keep in mind is that we're still in the very early days when it comes to the search for extraterrestrial intelligence. Saying there's a silence is a bit like if Columbus, looking to discover a new continent, only sailed 10 miles off the coast of Spain before turning back to say, 'Nothing out there!'

In 1967, the world health community launched a global effort to eradicate smallpox. It took a coordinated, worldwide effort, required the commitment of every government, and cost $130 million dollars. By 1977, smallpox had disappeared.