Current Projects
Grainflow on Mars
Once upon a time, seasonally varying dark streaks on Mars’ surface, known as recurring slope lineae (RSL), were some of the most poorly understood features on Mars
Everyday, these features were considered the best evidence for liquid water flow on the surface of Mars
Until one day, a competing hypothesis for the origin of these features, as well as other unique features including slope streaks and slumps, would form them via dry grainflows
Because of that, understanding how dry grainflows could simultaneously produce the diversity of RSL among other streak features across Mars has important implications for our understanding of water, aeolian processes and grainflow on Mars
Because of that, to identify and characterize wind-driven and local granular processes that explain the diversity of RSL and slope streak formation a quantitative model must be found to show how this process works in the Martian environment
Until finally, by assessing the conditions necessary for dry grainflows to produce the characteristics of these streak features we will be able to support or refute the hypothesis that RSL may be formed without water
We carried out a pilot study to validate that we can model observed RSL flow lengths using grain properties, slope characteristics, and sand volumes reasonable for Mars.
NASA Solar System Workings project begins this summer, at the conclusion of the 3-year study we will have a more thorough understanding of the role of dry grainflow processes and grainflow in aeolian environments in producing enigmatic slope features on Mars. We will answer the science questions, 1) How does aeolian sand transport influence RSL sites? and 2) If RSL and Slope Streaks are generated by dry grainflow, why do they start and stop on different slope angles and differ in scale?
The project involves a three-pronged approach including 1) contextual geomorphology with remote sensing, 2) experimental wind tunnel testing, and 3) simulated granular flow numerical modeling. By numerically modeling the flow volumes that produce RSL and Slope Streaks we will provide the first numerical constraints on the physics of dry granular flows that produce features on Mars that have been under investigation for over a decade.
JWST Observations
We obtained the highest-resolution spectra of the asteroid Psyche across a wavelength range of ~1-24 microns, and we are currently calibrating the data and investigating potential features across the spectra. I presented preliminary results at the Psyche team meeting in May and will present additional findings at the Gordon Research Conference in June. I also collaborated with the SwRI graphics department to get together an image representing our preliminary findings!
Planetary Rings
SwRI Press release describing my recent paper cataloguing all the UVIS solar occultations of Saturn’s rings for broader community access,
SwRI scientists have compiled 41 solar occultation observations of Saturn’s rings, encompassing data from NASA’s Cassini mission over the course of nearly 20 years. The compilation will aid future investigations of the particle size distribution and composition in Saturn’s rings, key factors in understanding their formation and evolution.
Credit:
Courtesy of NASA/JPL-Caltech/SSI/Cornell
Manuscript highlights:
- The Cassini UVIS instrument observed 41 solar occultations by Saturn’s rings in the EUV
- This manuscript serves as a guide to corresponding high-level data products delivered to the Planetary Data System
- Solar occultation optical depth measurements complement stellar occultation data constraining self-gravity wake properties
- Spectral trends from solar occultations yield insights into the particle composition and size distributions of the rings
And on a team to investigate rings around Jupiter, Uranus, and Neptune with a future project in the works.
Europa
Working with Europa Clipper UVS Science Team to conduct observation planning (contributing to synthetic photometric model to integrate into a web tool that will validate the anticipated SNR for the proposed observations with the instrument at Europa).
sjarmak.com 