A Caltech Library Service

Investigation of Past Habitable Environments through Remote Sensing of Planetary Surfaces


Stein, Nathaniel Thomas (2020) Investigation of Past Habitable Environments through Remote Sensing of Planetary Surfaces. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/cq9c-sg21.


Planetary surfaces record a history of potentially habitable environments throughout the solar system. This dissertation focuses on the characterization of three planetary surfaces to inform their evolution and past habitability: Earth (Chapter 2), Mars (Chapters 3-4), and Ceres (Chapters 5-6). In chapter 1, we introduce major questions driving the work presented in this thesis. In Chapter 2, we use a combination of UAV-based images and in-situ observations to characterize the processes that control the texture and distribution of modern microbial mats in the Turks and Caicos. We find that the surface texture and distribution of the mats is controlled primarily by subtle differences in elevation that drive significant changes in subaerial exposure time. Sedimentation and mechanical weathering from storm events also play a key role in controlling the distribution of mats. In Chapter 3, we apply a PCA-based regression method to stereo Curiosity Mastcam images to measure the structural orientation of the Murray formation. We constrain the dip to be effectively horizontal, which indicates that the Murray formation predates the creation of Aeolis Mons and is consistent with flat strata being deposited on an equipotential surface in a lacustrine setting. In Chapter 4, we summarize the investigation of networks of reticulate ridges on the surface of several rock slabs in the Murray formation using data from the Curiosity rover. We find that the features are preserved mudcracks that were likely deposited during a lowstand in a lake ~3.2-3.6 Ga. The mudcracks are one of few definitive textural markers of drying in the Murray formation and suggest a history of oscillating lake levels that led to intermittent exposure. In Chapter 5, we catalog bright spots on Ceres and propose mechanisms for their formation. We identify hundreds of Na-carbonate-bearing regions on Ceres. We show with a Monte Carlo impact model that these deposits must have been exposed within the last few hundred Ma. In Chapter 6, we investigate the source of shallow subsurface Na-carbonate deposits. We show that the deposits must have been emplaced in the last ~1 Ga and that the solid-state mobilization of water ice and hydrated Na-carbonates could simultaneously explain the formation of domes and large crater rim Na-carbonate exposures. Chapter 7 synthesizes the major results of this thesis and avenues for future exploration.

Item Type:Thesis (Dissertation (Ph.D.))
Subject Keywords:remote sensing, Mars, Ceres
Degree Grantor:California Institute of Technology
Division:Geological and Planetary Sciences
Major Option:Planetary Sciences
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Grotzinger, John P. (advisor)
  • Ehlmann, Bethany L. (co-advisor)
Thesis Committee:
  • Ehlmann, Bethany L. (chair)
  • Grotzinger, John P.
  • Lamb, Michael P.
  • Fischer, Woodward W.
Defense Date:29 May 2020
Non-Caltech Author Email:n.stein27 (AT)
Funding AgencyGrant Number
NSF Graduate Research FellowshipDGE-1144469
NASA MSL Participating Scientist ProgramUNSPECIFIED
Record Number:CaltechTHESIS:06092020-122543624
Persistent URL:
Related URLs:
URLURL TypeDescription adapted as Ch. 3 adapted as Ch. 4 adapted as Ch. 5
Stein, Nathaniel Thomas0000-0003-3385-9957
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:13810
Deposited By: Nathaniel Stein
Deposited On:09 Jun 2020 22:02
Last Modified:09 Dec 2020 16:58

Thesis Files

PDF - Final Version
See Usage Policy.


Repository Staff Only: item control page