1. Department of Aerospace, Physics and Space Sciences, Florida Institute of Technology, 150 W University Blvd, Melbourne, FL 32901, USA
2. Depto. Física Aplicada I, Escuela de Ingeniería de Bilbao, UPV/EHU, Bilbao 48013, Spain
3. Commission des Observations planétaires, Sociéte Astronomique de France, 75016 Paris, France
4. Department of Computer Science, University of Texas at San Antonio, 1 UTSA Circle, San Antonio, TX 78249, USA