Mars Workshop on Amazonian and Present-Day Climate
In mid-June, more than 30 Mars scientists and 17 students gathered in Lakewood, Colorado to outline the current understanding of active processes and environmental conditions occurring within the recent “Amazonian” and present-day martian climate, and the atmospheric and geologic records that those processes and conditions have created. This meeting was intended as a supplemental topical workshop, held between the most recent International Conference on Mars Polar Science and Exploration in 2016 and the one planned for 2020.
The meeting was convened by the Planetary Science Institute (Colorado location), with student travel grants funded by NASA’s Mars Program Office and program organization assistance from the Lunar and Planetary Institute. The conference received 41 abstracts, which were organized based on their focus: the atmosphere, polar caps and layered deposits (PLDs), surface changes, and non-polar features. Bruce Jakosky (Colorado University, Boulder) gave a keynote presentation focused on the history of water on Mars. All oral sessions featured substantial discussion time to allow for synthesis of individual topics and results into the scientific advancement of the bigger-picture understanding of Mars’ climate. Additionally, a poster session, pre-workshop social event, and mid-workshop field trip provided opportunities for attendees to share data, results, and ideas.
From the discussions, a consensus emerged that a top science objective for Mars Amazonian Climate studies is to identify, measure, and interpret the surface and subsurface record of Mars’ climate history. In particular, it is important to establish if and how the PLDs and other landforms and surface/subsurface materials record climate variations over annual-to-decadal, orbital (e.g., obliquity cycles), and/or longer timescales — so that we can begin to quantitatively read that record from high-resolution orbital images. Part of this work depends on gaining a strong understanding of current atmospheric processes and exchanges of volatiles with the surface/near-surface. Specifically, characterizing volatile reservoirs that presently or formerly exchange with the atmosphere and understanding how dust/clouds affect surface and atmospheric temperatures would place key constraints on environmental conditions and habitable regions during the recent past.
A preliminary list of key open science questions was defined that reflected this objective, as well as how deeply polar conditions and processes interact with the global Mars geologic and atmospheric systems:
- What are the timescale, completeness, and temporal resolution recorded in PLDs?
- How can we identify and interpret geologic and atmospheric records that volatiles leave outside the polar regions?
- What are the present and past fluxes of volatiles, particulates, and energy across the globe?
- How much material is contained within dust/sand/ice reservoirs, how are they formed, preserved, or depleted, and when?
- What is the mass/energy balance at the poles?
At the conclusion of the workshop, discussion turned to mission implementation. Engineers from Ball Aerospace and the Jet Propulsion Laboratory contributed insights regarding potentially relevant technical capabilities. Landing on the surface to enable access to the ice and provide in situ atmospheric and subsurface measurements was recommended by many participants. However, such a mission would potentially need to be capable of surviving the polar night, in addition to landing on and drilling into the martian polar cap. Measurements achievable by an orbiter were also discussed.
Contributions to a Planetary and Space Sciences special issue are welcome from the general community through February 28, 2019. We thank all attendees for contributing to the discussion, especially those who engaged in note-taking and additional synthesis discussion.
More information about the workshop, including the full program and abstracts, is available at https://www.hou.usra.edu/meetings/amazonian2018/.