A Search for Plasma Waves in the Distant Martian Environment

We present results from a wavelet analysis of MAVEN magnetometer (MAG) data from Sep. 22 through Sep. 27, 2014, during the first four orbits of the spacecraft around Mars. These orbits were highly elliptical with a periapsis of 410 km, an apoapsis of 44,500 km ( 13 RM), and a period of 35 hours. These unique orbits provide the opportunity to search for ion cyclotron waves in the distant Martian environment. We are particularly interested in ion cyclotron waves which are produced by Martian pickup ions such as H+ and O+. The observation of these waves enable an estimate of the pickup-ion density. Our wavelet analysis of MAVEN MAG data determines which frequencies are most prominent. We find spectral power at a variety of frequencies including significant signals at the proton and oxygen cyclotron frequencies. We present the results of our search and the implications for densities of planetary-derived plasma at far distances from Mars. We compare our findings with similar in-situ Mars Global Surveyor results and remotely sensed UV plasma emissions from the MAVEN ultraviolet imaging spectrometer.