When
3:30 p.m., March 25, 2010
Where
Kuiper Space Sciences Building 308
Dr. Jack Holt from the University of Texas Institute for Geophysics, is the scheduled speaker.
Abstract:
An entirely new form of planetary exploration began in 2005 when Mars Express, followed by Mars Reconnaissance Orbiter in late 2006, began returning data from the first radar sounders to orbit another planet. Placing this active geophysical technique in orbit allows us to complement high-resolution surface and near-surface observations across Mars with measurements of material properties in the vertical dimension, penetrating rocky surface layers and extending to depths of kilometers in ice. Assisted by experience with similar studies in Antarctica, we have gained significant new insights into both the state of massive ice deposits and processes governing the large-scale evolution of ice on Mars. In the northern polar layered deposits, radar has confirmed that the bulk composition is nearly pure water ice, and radar-based mapping of subsurface stratigraphy and structure has now revealed a previously unknown history of deposition and erosion leading to the formation of the two largest geomorphic anomalies there, Chasma Boreale and the pervasive spiral troughs. These features had eluded explanation since their discovery by Mariner 9 almost 40 years ago. Our new view of processes governing polar ice also provides critical context for evaluating climate models including the transfer of ice between the poles and lower latitudes where ice has been found in abundance by multiple recent missions and techniques. Given our new knowledge and an ability to conduct analog studies on Earth, it will be possible to tailor future radar missions to more thoroughly study Mars ice and to extend such studies to the icy moons of our solar system.
Abstract:
An entirely new form of planetary exploration began in 2005 when Mars Express, followed by Mars Reconnaissance Orbiter in late 2006, began returning data from the first radar sounders to orbit another planet. Placing this active geophysical technique in orbit allows us to complement high-resolution surface and near-surface observations across Mars with measurements of material properties in the vertical dimension, penetrating rocky surface layers and extending to depths of kilometers in ice. Assisted by experience with similar studies in Antarctica, we have gained significant new insights into both the state of massive ice deposits and processes governing the large-scale evolution of ice on Mars. In the northern polar layered deposits, radar has confirmed that the bulk composition is nearly pure water ice, and radar-based mapping of subsurface stratigraphy and structure has now revealed a previously unknown history of deposition and erosion leading to the formation of the two largest geomorphic anomalies there, Chasma Boreale and the pervasive spiral troughs. These features had eluded explanation since their discovery by Mariner 9 almost 40 years ago. Our new view of processes governing polar ice also provides critical context for evaluating climate models including the transfer of ice between the poles and lower latitudes where ice has been found in abundance by multiple recent missions and techniques. Given our new knowledge and an ability to conduct analog studies on Earth, it will be possible to tailor future radar missions to more thoroughly study Mars ice and to extend such studies to the icy moons of our solar system.
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