In this proposal, we will constrain the presence and lifetime of an ocean on mimas with numerical models of the evolution of mimas' largest topographic feature: the herschel impact crater. In the…

Purdue University was awarded a $118,951 research grant by a civilian federal agency effective January 1, 2025, with completion targeted by December 31, 2026. The award funds a one-year research initiative to model the evolution of Herschel Impact Crater on Saturn's moon Mimas and establish constraints on the potential existence of a subsurface ocean. The research employs numerical models to assess heat flow dynamics through Mimas' ice shell and topographic relaxation patterns, using the crater's largely unrelaxed state as a metric to bound the potential lifetime of any subsurface ocean. This work complements recent high-impact research suggesting a putative ocean could persist for tens of millions of years and will provide new, independent constraints on this scientific question. The contract is not set-aside and represents a focused research effort leveraging Purdue's existing personnel, expertise, and numerical modeling capabilities.

The research will be conducted at Purdue University's West Lafayette, Indiana campus. As a prominent land-grant research institution with extensive federal partnerships across multiple agencies including NASA, the National Science Foundation, and the Department of Defense, Purdue brings established credibility in advanced scientific research and development. The timing and scope of this award align with recent NASA and scientific community interest in Mimas' potential ocean, making this a timely contribution to planetary science objectives. The one-year duration reflects the proposing team's confidence in delivering focused, impactful results given their existing technical readiness and relevant published work in this domain.

In this proposal, we will constrain the presence and lifetime of an ocean on mimas with numerical models of the evolution of mimas' largest topographic feature: the herschel impact crater. In the presence of an ocean, heat flow through mimas' ICE shell will be high, which will enable relaxation of topography. Herschel, because IT is mimas' largest crater and is largely unrelaxed, therefore puts an upper limit on the lifetime of an ocean. If that upper limit is small enough, an ocean may not be favored. Alternatively, IT may be that limit is consistent with recent work that an ocean persists over tens of millions of years. Our work will advance the field when executed because IT will provide new constraints on a putative ocean that are complimentary to recent high-impact work. Over the next year, we will model and publish new constraints set on mimas' putative ocean through numerical modeling of the evolution of herschel. Although a one year duration proposal is shorter than is typically proposed in SSW, we think a focused, impactful proposal is optimal, appropriate, and low-risk in this case. As discussed below, our group already has the exact personnel, expertise, and numerical models needed to tackle this problem, and recent mimas publications make this a compelling and timely question to address immediately.