Charles Peirce’s most well-known contribution to logic and scientific methodology is his account of abduction. However, what exactly Peirce meant by abduction is subject to perennial dispute. My aim in this paper is two-fold: First, I interpret Peirce’s abduction through the lens of his research in geophysics and argue this supports interpreting it as a kind of inverse modeling. Second, I show that the methods Peirce outlined for managing the underdetermination of abductive inferences are the same as those deployed by geoscientists to manage the nonuniqueness of geophysical inversions. I conclude by emphasizing the value of reintegrating Peirce-the-Philosopher with Peirce-the-Geoscientist.