NRC Planetary Science Decadal Survey

1
NRC Planetary Science Decadal Survey

• Wendy Calvin
• Prof. Geological Sci Eng,
• University of Nevada - Reno
• Vice-Chair Mars Sub-Panel

for Western Space Grant Directors Meeting DRI,
18.Sept.09
2
Decadal Surveys

• Chartered by NASA, but provided by NRC as
  advisory arm of the NAS.
• Independent assessment of scientific priorities
  in a given area.
• Earth Science just completed (2007).
• Astronomy/Astrophysics and Planetary currently
  underway.
• Identify and Prioritize flight investigations
  believed to be gt 450M life cycle cost.
• Include infrastructure, RA, education,
  technology

3
New Frontiers in the Solar System (2003)

• Fundamental Science Questions
• 1st Billion Years of Solar System History
• Volatiles and Organics stuff of life
• Origin and Evolution of Habitable Worlds
• How Planetary Systems Work
• Example Recommended Missions
• Europa Geophysical Explorer
• Venus In-Situ
• Jupiter Polar Orbiter
• S. Pole Aiken (Lunar) Sample Return
• Mars Network
• Mars Sample Return

4
Planetary Science 2013-2022

• Overview of planetary science.
• Survey the state of knowledge, recent
  discoveries.
• Inventory top-level science questions that guide
  flight missions.
• Small (Discovery), Medium (New Frontiers), Large
  (Flagship) mission classes.
• (New) priorities for Mars and Earths Moon to be
  integrated with the rest of the Solar System.
• (New) assessment and cost modeling of flight
  concepts.
• (New) Astrobiology included in sub panels rather
  than separate sub-panel.

5
Committee Structure

• Steering Committee (Squyres, Soderblom)
• Vice-Chair of each sub panel (5)
• 9 others not affiliated with any subpanel
• Sub-Panels
• Primitive Bodies (Asteroids, Comets, KBOs,
  Meteorites, IDPs)
• Inner Planets (Mercury, Venus, Moon)
• Mars
• Giant Planets (JSUN, exoplanets, rings, fields)
• Satellites (Europa, Ganymede, Titan Enceladus,
  and many, many others)

http//sites.nationalacademies.org/SSB/CurrentProj
ects/ssb_052412
6
Mars Panel

• 13 Members
• Represent science from core to atmosphere
• Strategic missions and design well-considered
  through MEPAG community process.
• Goals and Objectives Living Document
• Life, Climate, Geology/Geophysics, Human
  Exploration
• Plans for 2016, 2018 Missions relatively stable
• 2016 Trace Gas Orbiter, 2018 Rover (Astrobio)
• International collaboration developing
• Exo-Mars, Mars Sample Return
• Just had 1st meeting, briefings from MEPAG
  community and mission studies.
• Community white papers just delivered.

7
Process/Timeline

• Sub panels meet, gather information, propose
  missions for study.
• Include White papers from community
• Each sub-panel has 2 meetings between Aug-Nov
  2009
• Steering committee prioritizes input from
  sub-panels into cross-solar system themes and
  goals.
• Strive for consensus and community ownership
• Fit within current budget constraints
• Draft document from sub panels Spring 2010
• Draft full report Fall/Winter 2010
• External review and release of final report
  summer 2011.

8
2003 Mars Themes / Key Questions

• Mars as a potential abode of life
• Does/Did life exist, how habitable?
• Water, atmosphere, and climate
• Sources, sinks, volatile reservoirs
• Atm evolution, dynamics, atm escape
• 3D distribution of water in the crust
• Structure and evolution of Mars
• Rock types, origin of crustal magnetism
• Internal structure, core dynamo
• Chronology, oxidation with depth

9
Why Mars?

1. Mars offers crucial information about the early
   evolution, internal structure, and origin of the
   terrestrial planets, including Earth.
2. Timeframe for evolution of life on Earth is
   largely absent from the rock record, but this era
   is preserved on Mars.
3. Mars provides a means to approach, and possibly
   answer, origin and evolution of life questions.
4. Excellent opportunity to investigate short- and
   long-term climate change.
5. Mars science has benefitted from a focused,
   dedicated program of exploration.

10
MEPAn Integrated Set of ActivitiesCreating a
True Program Structure
Year of Launch
2007
2001
2003
2005
1996
2011
2013
Mars Reconnaissance Orbiter
MAVEN
Mars Global Surveyor
Mars Odyssey
Curiosity
Opportunity
Phoenix
Spirit
Mars Pathfinder
Strategic, Core Missions
Competitive PI-Led Missions
10
11
Last Decade Discoveries Diverse Planet with
Complex History

• Mars has areas with diverse mineralogy, including
  alteration by water, with a change in mineralogy
  over time and spatial diversity of environments.
• In situ confirmation of increased water activity
  in the past.
• Pervasive water ice in globally distributed,
  near-surface reservoirs.
• Sources, phase changes, and transport of
  volatiles (H2O, CO2) are known some are
  quantified.
• Increasing evidence for geologically recent
  climate change.
• Dynamic change occurring even today landslides,
  new gullies, new impact craters, changing ice
  cover.
• Presence of methane indicative of active
  chemical processes either biogenic or abiotic.
• Based on much of the above, the perception of
  Potential for past Life has increased, and Modern
  Life may still be possible.

12
Last Decade Discoveries Diversity of
Environments
PHX

• Chemistry and morphology indicate changing
  environments throughout geologic history
• Acidic waters at Meridiani
• Basic waters at Phoenix landing site
• Mineralogy clays to sulfates to oxides

MER
Steno
MRO
Smith
Lyell
Gilbert area
Victoria Crater
-12
Hesperian subsurface water, diagenesis
13
Past Decadal Results Wide variety of
sedimentary deposits
Delta, showing phyllosilicate layers
Melas Chasma
MRO
Meridiani
MER
MRO
Large-scale sedimentary structures

• Depositional processes created a sedimentary
  record
• Developed in topographically low areas
• Spectacular stratification at multiple scales
• Evidence of persistent standing water, lakes
• Sediments systematically change in character with
  time
• Multiple facies recognized

Eberswalde Delta
Fine-scale sedimentary structures
-13
14
Past Decadal Results Distribution of Modern
Water
Global Near-Surface Reservoirs of Water
ODY

• Gamma Ray Spectrometer
• Global hydrogen abundance and equivalent H2O
• Ground ice to /-60 in high abundance

Phoenix results
PHX

• SHARAD and MARSIS
• Nearly pure water ice
• Distinct layering
• No deflection of crust
• Ice-cored lobate debris aprons in mid-latitudes

MRO MEX
-14
15
Past Decadal Results Periodic Climate Change

• Volatile-rich, latitude dependent deposits
  (mantle, glaciers, gullies, viscous flow) coupled
  to orbitally-forced climate change
• Periodicity of layering in the north polar cap
  deposits as well as sedimentary deposits

MGS, ODY, MEX MRO
16
Past Decadal Results Modern Methane
courtesy Mark Allen
NAI, RA
Courtesy Mike Mumma
NAI
Detection of Methane on Mars
MEX NAI RA
Abiotic?
Biotic?
Evidence of an active subsurface?
courtesy Lisa Pratt
17
Past Decadal Results Mars Planetary Evolution

• Hydrous Mineralogy Changed Over Time
• Phyllosilicate minerals (smectite clay, chlorite,
  kaolinite) formed early
• Evaporates dominated by sulfate formed later with
  opal/hydrated silica
• Few hydrated mineral deposits since
• Evolution of Aqueous, Fluvial and Glacial,
  Morphology with Time
• Valley networks, lake systems
• Gullies
• Viscous flow, glaciers, latitude dependant mantle

acidic
Neutral pH
Sulfates
Anhydrous Ferric Oxides
Clays
18
Questions for the Next Decade

• Integrating the MEPAG science priorities and the
  programmatic factors, these specific questions
  are highest priority for the next decade.
• What is the diversity and nature of aqueous
  geologic environments? (Goal I, II, III--MSL will
  contribute)
• What is the detailed mineralogy of the diverse
  suite of geologic units and what are their
  absolute ages? (Goal II, III)
• Are reduced carbon compounds preserved and, if
  so, in what geologic environments? (Goal I--MSL
  may contribute)
• What is the complement of trace gases in the
  atmosphere and what are the processes that govern
  their origin, evolution, and fate? (Goal I, II,
  III)
• How does the planet interact with the space
  environment, and how has that affected its
  evolution? (Goal IIaddressed by MAVEN mission)
• What is the record of climate change over the
  past 10, 100, and 1000 Myrs? (Goal II, III)
• What is the internal structure and activity?
  (Goal III)