P21A-2070
First Results of the MAVEN Magnetic Field Investigation
Tuesday, 15 December 2015
Poster Hall (Moscone South)
John E P Connerney1, Jared R Espley1, Gina A DiBraccio2, Jacob Gruesbeck3, David L Mitchell4, Jasper S Halekas5, Christian Xavier Mazelle6, David Brain4, Bruce Martin Jakosky7 and Ronald J Oliversen1, (1)NASA Goddard Space Flight Center, Greenbelt, MD, United States, (2)NASA Goddard Space Flight Center, Solar System Exploration Division, Greenbelt, MD, United States, (3)University of Maryland College Park, College Park, MD, United States, (4)University of California Berkeley, Berkeley, CA, United States, (5)University of Iowa, Physics and Astronomy, Iowa City, IA, United States, (6)University Paul Sabatier Toulouse III, Toulouse Cedex 09, France, (7)Laboratory for Atmospheric and Space Physics, Boulder, CO, United States
Abstract:
The MAVEN spacecraft approaches the end of its first year in orbit, systematically mapping the interaction region about Mars with a focus on atmospheric escape. The comprehensive instrument suite aboard MAVEN has busied itself in mapping the magnetosphere, magnetosheath, magnetotail, and extended atmospheric corona in near-Mars space. MAVEN carries two magnetic field sensors (fluxgate magnetometers) as part of the particles and fields package (PFP); they sample the ambient magnetic field from a vantage point on at the outer edge of each solar array. We characterized relatively minor spacecraft-generated magnetic fields using a series of in-flight subsystem tests and spacecraft maneuvers. Dynamic spacecraft fields (≤ 1 nT) associated with the operation of specific solar array circuits are compensated for using spacecraft engineering telemetry to identify active circuits and monitor their electrical current production. Static spacecraft magnetic fields are monitored using spacecraft roll maneuvers. Accuracy of measurement of the environmental magnetic field is demonstrated by comparison with field directions deduced from the symmetry properties of the electron distribution function measured by the Solar Wind Electron Analyzer (SWEA). We compile magnetometer observations to characterize intense crustal magnetic fields, the solar wind interaction with Mars, and ubiquitous proton cyclotron and 1-Hz waves in the upstream solar wind (ion foreshock region). The figure below compiles observations of magnetic fluctuations obtained by MAVEN in near-Mars space. The map of magnetic fluctuations reveals the statistical extent of the magnetosheath, confined between the bow shock and the magnetic pile-up region.
