APL Colloquium

December 3, 1999

Colloquium Topic: Mars Global Surveyor

The discovery by Mars Global Surveyor of strongly magnetized, linearly structured areas of the Martian crust poses new and unsolved challenges concerning the formation and thermal evolution of the planet, its internal dynamo and the physical/chemical processes responsible for the observed intense magnetization. Crustal magnetism at Mars exceeds by more than an order of magnitude that observed at Earth and extends over thousands of kilometers. Available Earth-based models cannot easily account at present for the observed extent and intensity of the Martian crust magnetization. Although single domain magnetite mineralogy can in principle account for the observed intensity, it is difficult to reconcile the large volume required to explain the Mars observations with their terrestrial counterparts. The talk will focus on the latest results of analyses, laboratory work and models of selected crustal magnetic sources.

Colloquium Speaker: Mario Acuña

Dr. Mario Acuña was born in Córdoba, Argentina in 1940 where he received his undergraduate degree in humanities and economics. He earned the M.S.E.E degree from the University of Tucumán, Argentina in 1967 and the Ph.D. degree in Space Physics from The Catholic University of America, Washington, DC in 1974. In 1967 he joined the Fairchild-Hiller Corporation where he became Head of the Electronic Systems Division in 1968. Since 1969 Dr. Acuña has been associated with GSFC where his interests have centered on aerospace instrumentation and experimental investigations of the magnetic fields and plasmas in the solar system. As Principal Investigator, Co-Investigator, Instrument Scientist and Project Scientist he has played a crucial part in many NASA missions, including Explorers 47 & 50, ISEE3, Mariner 10, Pioneer 11, Voyagers 1 & 2, MAGSAT, Project Firewheel, Viking, AMPTE, ISPM (NASA/ESA, currently ULYSSES), the GIOTTO mission to Comet Halley, and numerous other programs. In 1986 he was selected as Principal Investigator for the Mars Observer Magnetic Field Investigation now replaced by the Mars Global Surveyor Mission. His research laboratory is recognized throughout the world as the leader in the development of instrumentation for the measurement of geophysical magnetic fields as well as plasmas, electromagnetic waves, gamma and X-rays. Since 1984 the laboratory has also supported the Defense Meteorological Satellite Program with the provision of advanced magnetic field instrumentation. Dr. Acuña currently serves as US Project Scientist (and Science Manager) for the International Solar Terrestrial Physics Program, a $2.4B coordinated research effort by Japan, Europe, Russia and the US involving more than 1000 investigators and the launch of at least seven spacecraft in the middle 90's, and Project Scientist for the SAC cooperative program with Argentina, Brazil, Italy and Denmark. Dr. Acuña is also the Team Leader for the NEAR Magnetic Field Experiment, is a Lead Co-Investigator in the Magnetic Field and Electron Reflectometer experiment for the Lunar Prospector Mission currently in orbit around the Moon, and is the Instrument Scientist for the ACE spacecraft Magnetic Field Experiment launched in August 1997 and now in orbit around the L1 libration point between the Earth and the Sun. In August of 1998 he was selected by NASA as Co-Investigator in the Inner Magnetosphere Explorer Mission (IMEX). Dr. Acuña's extensive research deals with planetary exploration, magnetic fields and plasmas in the solar system, instrumentation for space research and other related subjects. He has been honored by NASA and other organizations with numerous prestigious awards including the Schneebaum Memorial Award for Engineering Excellence, the NASA Medal for Exceptional Scientific Achievement, the Exceptional Service Medal, the Award of Merit and the Distinguished Service Medal (NASA¹ s highest honor) in recognition of his contributions to engineering, physics and space research. In 1991 he received the Outstanding Engineering Achievement Award of the Catholic University Alumni Association, the Outstanding Technical Contribution Award of the Society of Hispanic Professional Engineers and was appointed as a Senior Fellow by GSFC. In 1985 he was selected by the IEEE Magnetics Society as one of three Distinguished Lecturers to speak throughout the US on the subject of Space Magnetometry. Dr. Acuña is a member of the American Geophysical Union, the Institute of Electrical and Electronics Engineers, the Scientific Research Society of North America (Sigma Xi), the Committee for Space Research and International Association of Geomagnetism and Aeronomy, the Inter-Agency Consultative Group, WG-1, and is a founding member of the Latin American Association of Space Geophysics (ALAGE).