Home from Away: The Earth as an Analogue for Understanding Planetary Geologic Processes

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The planets and moons in our solar system represent a diverse set of worlds, shaped by different geologic processes. Studying their surface geology teaches us about how planets form and evolve over time, as impact cratering, volcanism, tectonism, and erosion shape the landscape. The best way to study the geology of distant worlds is to send humans or landers there, but this is a complex and expensive endeavour. Instead, most of the information we have about other planets comes from remote observations from Earth-based and orbital telescopes. To understand the geology of our planetary neighbours, we must understand how to relate remote sensing data to the physical and chemical properties of their surfaces. To do this, we can study analogue environments on Earth, where ground truth information is relatively simple to obtain. This ground truth can be correlated to corresponding remote sensing data and used to make extrapolations about the geology of other planetary surfaces. The long-term goal of my research program is to characterize the processes working to shape the landscapes of the planets and moons in our solar system, by conducting field work in a diverse set of terrains and comparing the observations to remote sensing data. This will be accomplished through three short-term objectives: 1. To understand how impact melt is emplaced around fresh lunar craters: Given the absence of erosion on the Moon, lunar impact craters serve as pristine laboratories for studying the impact cratering process. One feature that is commonly observed around fresh lunar craters is flow-like deposits of impact melt. We will examine lunar impact melt deposits with remote sensing instruments to constrain their composition, and compare the data to analogue environments on Earth. 2. To determine how impact craters are modified by erosion on Saturn's moon Titan: Quantifying the amount of erosion on other worlds is difficult, since the original surface topography is unknown. By studying impact craters on Earth, we can constrain the processes working to shape craters on other worlds. We propose to use data from small aerial drones to remotely identify impact melt in an eroded impact crater on Earth, and satellite imagery to characterize eroded impact structures on Earth and Titan. 3. To constrain how lava flows are emplaced on Mars: Volcanism is one of the most common geologic processes on Mars. To understand how Martian lava flows are emplaced and modified over time, we will characterize the surface roughness of a lava flow in Iceland with a backpack LiDAR system. We will compare this data to publicly available radar and thermal infrared images of the site. By carrying out these objectives, we will obtain valuable data that can be used to constrain the geologic processes that have shaped the worlds in our solar system. This, in turn, will teach us about the evolution of Earth and provide insight into how the planet will adapt to future geologic changes.