NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
The Sustainability of Habitability on Terrestrial Planets: Insights, Questions, and Needed Measurements from Mars for Understanding the Evolution of Earth-Like WorldsWhat allows a planet to be both within a potentially habitable zone and sustain habitability over long geologic time? With the advent of exoplanetary astronomy and the ongoing discovery of terrestrial-type planets around other stars, our own solar system becomes a key testing ground for ideas about what factors control planetary evolution. Mars provides the solar systems longest record of the interplay of the physical and chemical processes relevant to habitability on an accessible rocky planet with an atmosphere and hydrosphere. Here we review current understanding and update the timeline of key processes in early Mars history. We then draw on knowledge of exoplanets and the other solar system terrestrial planets to identify six broad questions of high importance to the development and sustaining of habitability (unprioritized): (1) Is small planetary size fatal? (2) How do magnetic fields influence atmospheric evolution? (3) To what extent does starting composition dictate subsequent evolution, including redox processes and the availability of water and organics? (4) Does early impact bombardment have a net deleterious or beneficial influence? (5) How do planetary climates respond to stellar evolution, e.g., sustaining early liquid water in spite of a faint young Sun? (6) How important are the timescales of climate forcing and their dynamical drivers? Finally, we suggest crucial types of Mars measurements (unprioritized) to address these questions: (1) in situ petrology at multiple units/sites; (2) continued quantification of volatile reservoirs and new isotopic measurements of H, C, N, O, S, Cl, and noble gases in rocks that sample multiple stratigraphic sections; (3) radiometric age dating of units in stratigraphic sections and from key volcanic and impact units; (4) higher-resolution measurements of heat flux, subsurface structure, and magnetic field anomalies coupled with absolute age dating. Understanding the evolution of early Mars will feed forward to understanding the factors driving the divergent evolutionary paths of the Earth, Venus, and thousands of small rocky extra solar planets yet to be discovered.
Document ID
20170003174
Acquisition Source
Goddard Space Flight Center
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Ehlmann, B. L.
(California Inst. of Tech. Pasadena, CA, United States)
Anderson, F. S.
(Southwest Research Inst. Boulder, CO, United States)
Andrews-Hanna, J.
(Southwest Research Inst. Boulder, CO, United States)
Catling, D. C.
(Washington Univ. Seattle, WA, United States)
Christensen, P. R.
(Arizona State Univ. Tempe, AZ, United States)
Cohen, B. A.
(NASA Marshall Space Flight Center Huntsville, AL, United States)
Dressing, C. D.
(California Inst. of Tech. Pasadena, CA, United States)
Edwards, C. S.
(University of Northern Arizona Flagstaff, AZ, United States)
Elkins-Tanton, L. T.
(Arizona State Univ. Tempe, AZ, United States)
Farley, K. A.
(California Inst. of Tech. Pasadena, CA, United States)
Fassett, C. I.
(NASA Marshall Space Flight Center Huntsville, AL, United States)
Mahaffy, Paul
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
McCubbin, F. M.
(NASA Johnson Space Center Houston, TX, United States)
Niles, P. B.
(NASA Johnson Space Center Houston, TX, United States)
Zahnle, K. J.
(NASA Ames Research Center Moffett Field, CA, United States)
Date Acquired
April 7, 2017
Publication Date
October 29, 2016
Publication Information
Publication: Journal of Geophysical Research: Planets
Publisher: AGU Publications
Volume: 121
Issue: 10
ISSN: 2169-9097
e-ISSN: 2169-9100
Subject Category
Lunar And Planetary Science And Exploration
Report/Patent Number
GSFC-E-DAA-TN40473
Distribution Limits
Public
Copyright
Other
Keywords
rocky exoplanets
evolution
Mars

Available Downloads

There are no available downloads for this record.
No Preview Available