P54A-06
Radio Occultation Measurements of Pluto’s Atmosphere with New Horizons
Friday, 18 December 2015: 17:12
2007 (Moscone West)
David P Hinson1, Ivan Linscott2, G Leonard Tyler2, Michael Keith Bird3, Martin Paetzold4, Darrell F Strobel5, Michael E Summers6, William W Woods2, Alan Stern7, Harold A Weaver Jr8, Catherine Olkin9, Leslie Ann Young9, Kimberly Ennico Smith10, Randy Gladstone11, Thomas Greathouse11, Joshua Kammer9, Alex Harrison Parker9, Joel W Parker9, Kurt D Retherford12, Eric Schindhelm7, Kelsi N Singer9, Andrew Steffl13, Constantine Tsang9 and Maarten Versteeg12, (1)SETI Institute, Mountain View, CA, United States, (2)Stanford University, Stanford, CA, United States, (3)Univ Bonn, Bonn, Germany, (4)Univ Cologne, Cologne, Germany, (5)Johns Hopkins Univ, Baltimore, MD, United States, (6)Geo Mason-Physics & Astronomy, Fairfax, VA, United States, (7)Southwest Research Institute, Boulder, CO, United States, (8)Applied Physics Laboratory Johns Hopkins, Laurel, MD, United States, (9)Southwest Research Institute Boulder, Boulder, CO, United States, (10)NASA Ames, Moffet Field, CA, United States, (11)Southwest Research Inst, San Antonio, TX, United States, (12)Southwest Research Institute, San Antonio, TX, United States, (13)Southwest Research Institute Boulder, Dept Space Studies, Boulder, CO, United States
Abstract:
The reconnaissance of the Pluto System by New Horizons included radio occultations at both Pluto and Charon. This talk will present the latest results from the Pluto occultation. The REX instrument onboard New Horizons received and recorded uplink signals from two 70-m antennas and two 34-m antennas of the NASA Deep Space Network - each transmitting 20 kW at 4.2-cm wavelength - during a diametric occultation by Pluto. At the time this was written only a short segment of data at occultation entry (193°E, 17°S) was available for analysis. The REX measurements extend unequivocally to the surface, providing the first direct measure of the surface pressure and the temperature structure in Pluto’s lower atmosphere. Preliminary analysis yields a surface pressure of about 10 microbars, smaller than expected. Data from occultation exit (16°E, 15°N) are scheduled to arrive on the ground in late August 2015. Those observations will yield an improved estimate of the surface pressure, a second temperature profile, and a measure of the diameter of Pluto with a precision of a few hundred meters.
