trendspotter writes with news of research indicating that impact events might be responsible for seeding the Earth with reactive forms of the precursors to amino acids. From the article: "Early Earth was not very hospitable when it came to jump starting life. In fact, new research shows that life on Earth may have come from out of this world. Lawrence Livermore scientist Nir Goldman and University of Ontario Institute of Technology colleague Isaac Tamblyn (a former LLNL postdoc) found that icy comets that crashed into Earth millions of years ago could have produced life building organic compounds, including the building blocks of proteins and nucleobases pairs of DNA and RNA. Comets contain a variety of simple molecules, such as water, ammonia, methanol and carbon dioxide, and an impact event with a planetary surface would provide an abundant supply of energy to drive chemical reactions." The paper (PDF).