1. Instituto de Quimica, Universidad Nacional Autonoma de Mexico, Ciudad Universitaria, Mexico D.F.
2. NASA Astrobiology Institute, The University of Arizona, Tucson, Arizona.
3. Department of Chemistry, The University of Arizona, Tucson, Arizona.
4. Department of Astronomy, The University of Arizona, Tucson, Arizona.
5. Department of Steward Observatory, The University of Arizona, Tucson, Arizona.