Observations of a potential Mars analog at the microscale using over-inspired methods: A 10-sol observation of Fort Rock tuff ring

摘要

The terrestrial geologist's hand lens is a fundamental tool for identifying and correlating rocks and minerals. We used rover-inspired methods of remote hand lens–scale data acquisition to conduct reconnaissance of a well-characterized Martian analog field site. The objective was to determine if the current methodologies associated with the use of remote hand lens–scale imagers maximizes science return. Field geologists provided with hand lens–scale images of targets in geologic context could correctly identify many important characteristics of those targets. However, they could not fully confirm or rule out any formation hypothesis using the data provided solely through rover-driven observational strategies. This was due to (1) a lack of "intermediate-scale," or millimeter- to centimeter-scale images providing important contextual information for the targets studied and (2) the limited number of hand lens–scale images that were taken using rover-driven methodology. We conclude that the benefits of the hand lens as an effective triage tool and discriminator of microtexture are limited using current rover-driven methodology because the hand lens–type imager is not deployed frequently, and resulting data cannot be used to fully support geochemical observations. We recommend pursuing ways to increase the number of images that can reasonably be acquired at the hand lens scale. In order for hand lens–scale imaging to be fully effective, textural characteristics diagnostic of the nature of a geologic site need to be identifiable at a number of different resolutions; rover microscale observational strategies must include more contextual imaging.