Planned Products of the Mars Structure Service for the InSight Mission to Mars

Abstract

The InSight lander will deliver geophysical instruments to Mars in 2018, including seismometers installed directly on the surface (Seismic Experiment for Interior Structure, SEIS). Routine operations will be split into two services, the Mars Structure Service (MSS) and Marsquake Service (MQS), which will be responsible, respectively, for defining the structure models and seismicity catalogs from the mission. The MSS will deliver a series of products before the landing, during the operations, and finally to the Planetary Data System (PDS) archive. Prior to the mission, we assembled a suite of a priori models of Mars, based on estimates of bulk composition and thermal profiles. Initial models during the mission will rely on modeling surface waves and impact-generated body waves independent of prior knowledge of structure. Later modeling will include simultaneous inversion of seismic observations for source and structural parameters. We use Bayesian inversion techniques to obtain robust probability distribution functions of interior structure parameters. Shallow structure will be characterized using the hammering of the heatflow probe mole, as well as measurements of surface wave ellipticity. Crustal scale structure will be constrained by measurements of receiver function and broadband Rayleigh wave ellipticity measurements. Core interacting body wave phases should be observable above modeled martian noise levels, allowing us to constrain deep structure. Normal modes of Mars should also be observable and can be used to estimate the globally averaged 1D structure, while combination with results from the InSight radio science mission and orbital observations will allow for constraint of deeper structure

Mars core structure—concise review and anticipated insights from InSight

“…8), but this is not predicted by the core liquid model used (see the "Appendix" section). Panning et al 's (2017) seismic wavespeed model brings mantle shear-wave speeds very close to core compressional wave speed, holding out the hope that the shallow core may be illuminated better by SKS and SKKS.…”

“…In contrast, with R11DW, the outermost outer core's structure will be less visible. Owing to SKS' high amplitude (Panning et al 2017) and polarization in the vertical plane, it should be visible with the InSight instrumentation. This arrival's travel time curve will probably be the main way to determine core structure since the PKP amplitude is considerably lower.…”

“…The review is concise, forfeiting a broad topical survey to focus instead on how the seismological information will elucidate core structure. The reviews of InSight mission seismology objectives found in Panning et al (2015Panning et al ( , 2017 cover aspects of marsquake location precision and silicate mantle structure.…”

The Noise Model of the SEIS Seismometer of the InSight Mission to Mars

“…The primary methods used to retrieve the internal structure are described in Panning et al (2015Panning et al ( , 2016 for the Internal structure and by Khan et al (2016) and Böse et al (2017) for the seismicity and source locations.…”

“…Many other applications can be made with the noise model: for example generating synthetic noise signals for internal structure inversion methods Panning et al (2016), or trying to estimate the seismic "low noise model" of Mars. Ongoing studies-for example Pou et al (2016) propose to extend this work to lower frequencies, in order to estimate the environment background for gravimetric applications of the seismometer, such as the Phobos tide measurements described by Van Hoolst et al (2003).…”