Two years ago, NASA took a chance and launched a new field of research christened “Astrobiology” with a bold Nobel laureate at the helm and about $10 million for research. This week, at the first ever Astrobiology Science Conference, NASA organizers were surprised when 600 scientists — three times as many as expected — showed up brimming with research papers, new ideas and enthusiasm about the questions of origins and evolution of life in the universe.