تقرير
Impact-Seismic Investigations of the InSight Mission
| العنوان: | Impact-Seismic Investigations of the InSight Mission |
|---|---|
| المؤلفون: | Ingrid Daubar, Philippe Lognonne, Nicholas A. Teanby, Katarina Miljkovic, Jennifer Stevanovic, Jeremie Vaubaillon, Balthasar Kenda, Taichi Kawamura, John Clinton, Antoine Lucas, Melanie Drilleau, Charles Yana, Gareth S. Collins, Don Banfield, Matthew Golombek, Sharon Kedar, Nicholas Schmerr, Raphael Garcia, Sebastien Rodriguez, Tamara Gudkova, Stephane May, Maria Banks, Justin Maki, Eleanor Sansom, Foivos Karakostas, Mark Panning, Nobuaki Fuji, James Wookey, Martin van Driel, Mark Lemmon, Veronique Ansan, Maren Bose, Simon Stahler, Hiroo Kanamori, James Richardson, Suzanne Smrekar, W Bruce Banerdt |
| المصدر: | Space Science Reviews. 214(8) |
| بيانات النشر: | United States: NASA Center for Aerospace Information (CASI), 2018. |
| سنة النشر: | 2018 |
| مصطلحات موضوعية: | Space Sciences (General) |
| الوصف: | Impact investigations will be an important aspect of the InSight mission. One of the scientific goals of the mission is a measurement of the current impact rate at Mars. Impacts will additionally inform the major goal of investigating the interior structure of Mars. In this paper, we review the current state of knowledge about seismic signals from impacts on the Earth, Moon, and laboratory experiments. We describe the generalized physical models that can be used to explain these signals. A discussion of the appropriate source time function for impacts is presented, along with spectral characteristics including the cutoff frequency and its dependence on impact momentum. Estimates of the seismic efficiency (ratio between seismic and impact energies) vary widely. Our preferred value for the seismic efficiency at Mars is 5 × 10−4, which we recommend using until we can measure it during the InSight mission, when seismic moments are not used directly. Effects of the material properties at the impact point and at the seismometer location are considered. We also discuss the processes by which airbursts and acoustic waves emanate from bolides, and the feasibility of detecting such signals. We then consider the case of impacts on Mars. A review is given of the current knowledge of present-day cratering on Mars: the current impact rate, characteristics of those impactors such as velocity and directions, and the morphologies of the craters those impactors create. Several methods of scaling crater size to impact energy are presented. The Martian atmosphere, although thin, will cause fragmentation of impactors, with implications for the resulting seismic signals. We also benchmark several different seismic modeling codes to be used in analysis of impact detections, and those codes are used to explore the seismic amplitude of impactinduced signals as a function of distance from the impact site. We predict a measurement of the current impact flux will be possible within the timeframe of the prime mission (one Mars year) with the detection of ∼ a few to several tens of impacts. However, the error bars on these predictions are large. Specific to the InSight mission, we list discriminators of seismic signals from impacts that will be used to distinguish them from marsquakes. We describe the role of the InSight Impacts Science Theme Group during mission operations, including a plan for possible night-time meteor imaging. The impacts detected by these methods during the InSight mission will be used to improve interior structure models, measure the seismic efficiency, and calculate the size frequency distribution of current impacts. |
| نوع الوثيقة: | Report |
| اللغة: | English |
| تدمد: | 1572-9672 0038-6308 |
| DOI: | 10.1007/s11214-018-0562-x |
| URL الوصول: | https://ntrs.nasa.gov/citations/20205003836 |
| ملاحظات: | 847459.02.01.16.40 ANR-10-LABX-0023 ANR-11-IDEX-0005-02 DE180100584 DP180100661 |
| رقم الأكسشن: | edsnas.20205003836 |
| قاعدة البيانات: | NASA Technical Reports |
Find this article in full text from Springer Verlag. 
Full Text Finder | تدمد: | 15729672 00386308 |
|---|---|
| DOI: | 10.1007/s11214-018-0562-x |