Destination Dwarf Planets: A Panel Discussion OPAG, August 2019 Convened: Orkan Umurhan (SETI/NASA-ARC) Co-Panelists: Walt Harris (LPL, UA) Kathleen Mandt (JHUAPL) Alan Stern (SWRI) Dwarf Planets/KBO: a rogues gallery Triton Unifying Story for these bodies awaits Perihelio n/ Diamet Aphelion DocumentGoals 09.2018) from OPAG (Taken Name Surface characteristics Other observations/ hypotheses Moons er (km) /Current Distance (AU) Eris ~2326 P=38 Appears almost white, albedo of 0.96, higher Largest KBO by mass second Dysnomia A=98 than any other large Solar System body except by size. Models of internal C=96 Enceledus. Methane ice appears to be quite radioactive decay indicate evenly spread over the surface that a subsurface water ocean may be stable Haumea ~1600 P=35 Displays a white surface with an albedo of 0.6- Is a triaxial ellipsoid, with its Hi’iaka and A=51 0.8 , and a large, dark red area . Surface shows major axis twice as long as Namaka C=51 the presence of crystalline water ice (66%-80%) , the minor. Rapid rotation (~4 but no methane, and may have undergone hrs), high density, and high resurfacing in the last 10 Myr. Hydrogen cyanide, albedo may be the result of a phyllosilicate clays, and inorganic cyanide salts giant collision. Has the only may be present , but organics are no more than ring system known for a TNO. 8% 2007 OR10 ~1535 P=33 Amongst the reddest objects known, perhaps due May retain a thin methane S/(225088) A=101 to the abundant presence of methane frosts atmosphere 1 C=87 (tholins?) across the surface.Surface also show the presence of water ice. P=39 Methane, ethane, tholins, and possibly nitrogen May have an atmosphere up MK 2 A=53 present on the surface. Smaller amounts of to 4-12 nanobar at surface. ethylene, acetylene, and high-mass alkanes (like May have N convecting Makemake ~1427 C=52 2 propane) may be present. Appears red in the layer. visible spectrum. Some nitrogen present, but much less than on Pluto or Triton. Perihelio n/ Diamet Aphelion DocumentGoals 09.2018) from OPAG (Taken Name Surface characteristics Other observations/ hypotheses Moons er (km) /Current Distance (AU) ~1092 P=42 Surface is moderately red, and albedo may Crystalline water ice indicates that Weywot Quaoar A=45 be as low as 0.1, maybe indicating that temperature rose to at least -110°K C=42 fresh ice has disappeared from its surface. sometime in the last 10 Ma, Crystalline water ice exists at the surface. possible cryovolcanism spurred by Small presence (5%) of methane and internal radioactive decay ethane ice Sedna ~1030 P=76 Has an albedo of 0.32, a homogeneous One of the most distant- known None A=936 surface in color and spectrum, and one of objects in the Solar System, with a detected C=86 the reddest surfaces in the Solar System, highly eccentric orbit, leading to perhaps caused by a surface coating of speculation that it may be a tholins. Surface composition upper limits member of the inner Oort cloud, in are 60% for methane and 70% for water ice. addition to extra- solar origin 24% Triton-type tholins, 7% amorphous hypotheses. Models of internal carbon, 10% nitrogen, 26% methanol, and radioactive decay indicate that a 33% methane have been suggested for the subsurface ocean may be stable. surface composition. Orcus 917 P=31 Has an albedo of 0.3, is gray in color, and is A plutino in a 2:3 resonance with Vanth A=48 rich in crystalline water ice, mixed with Neptune. Crystalline water ice, and C=48 tholins . Methane and ammonia may be possible ammonia ice, may present. Water and methane ices can cover indicate surface renewal by no more than 50% and 30% of the surface cryovolcanism. Models of internal respectively.,. radioactive decay indicate that a subsurface ocean may be stable. V&V Crosscutting Science Themes and Priority Questions, and candidate missions relevant to OPAG Crosscutting Candidate future missions Science Priority Questions to outer planets Themes 1. What were the initial stages, conditions, and processes of solar system formation and the Ice Giants mission, KBO nature of incorporated interstellar matter? mission, Saturn Probe 2. How did the giant planets and their satellite Ice Giants mission, Saturn systems accrete, and is there evidence that they Probe, Io Observer, multiple New Worlds migrated to new orbital positions? Ocean Worlds missions (ORIGINS) 3. What governed the accretion, supply of water, Ice Giants mission, KBO chemistry, and internal differentiation of the inner mission, Io Observer, Titan Building planets and the evolution of their atmospheres, mission (see Section 8.0) and what roles did bombardment by large Planetary habitats projectiles play? V&V Crosscutting Science Themes and Priority Questions, and candidate missions relevant to OPAG Crosscutting Candidate future missions Science Priority Questions to outer planets Themes 4. What were the primordial sources of organic Ice Giants mission, multiple matter, and where does organic synthesis Ocean Worlds missions, KBO continue today? mission 5. Did Mars or Venus host ancient aqueous environments conducive to early life, and is there N/A evidence that life emerged? 6. Beyond Earth, are there contemporary habitats elsewhere in the solar system with necessary Multiple Ocean Worlds Planetary Habitats conditions, organic matter, water, energy, and missions, Ice Giants mission nutrients to sustain life, and do organisms live there now? V&V Crosscutting Science Themes and Priority Questions, and candidate missions relevant to OPAG Crosscutting Candidate future missions Science Priority Questions to outer planets Themes 7. How do the giant planets serve as laboratories Ice Giants mission, Saturn to understand Earth, the solar system, and probe, multiple Ocean Worlds extrasolar planetary systems? missions, Io Observer 8. What solar system bodies endanger Earth’s N/A biosphere, and what mechanisms shield it? 9. Can understanding the roles of physics, Ice Giants mission, Saturn chemistry, geology, and dynamics in driving Probe, Titan mission, Io SYSTEM planetary atmospheres and climates lead to a Observer, KBO mission better understanding of climate change on Earth? 10. How have the myriad chemical and physical WORKINGS OF SOLAR WORKINGS OF processes that shaped the solar system operated, All missions interacted, and evolved over time? On the Value of a Pluto-Charon System Orbiter O.M. Umurhan with prime assistance from: Jason Hofgartner1, Bonnie Buratti1, Marc Buie2, Veronica Bray3, Emmanuel Lellouch4 1. Jet Propulsion Laboratory, California Institute of Technology; 2. Southwest Research Institute; 3. University of Arizona; 4. Observatoire de Paris, Meudon; © 2019 OPAG. Government sponsorship acknowledged. Pre-Decisional Information - For Planning and Discussion Purposes Only On the Value of a Pluto-Charon System Orbiter O.M. Umurhan with prime assistance from: Jason Hofgartner1, Bonnie Buratti1, Marc Buie2, Veronica Bray3, Emmanuel Lellouch4 “…because it has a little bit of all the KBO Dwarf Planets, that’s why” 1. Jet Propulsion Laboratory, California Institute of Technology; 2. Southwest Research Institute; 3. University of Arizona; 4. Observatoire de Paris, Meudon; © OPAG. Government sponsorship acknowledged. Pre-Decisional Information - For Planning and Discussion Purposes Only Diverse, Unique, Ongoing, Endogenic and Exogenic , Liquids?, Stratigraphy: Crust? Glaciers and volatile caps? Pluto Geology Polar night unknown, non-encounter side needs resolution. Global Map, most desirable. Instruments: Color cameras (narrow and wide angle), Altimeter, IR spectral imager, Polar night imaging: Radar, Laser, Lyman-α imager? Priority Science Question(s) Addressed 10. How have the myriad chemical and physical processes that shaped the solar system operated, interacted, and evolved over Cryovolcanism Glaciers time? Convection Sublimation Interior: Ocean? (likely) If so depth, thickness, composition? Sputnik Planitia: Mascon and Polar wander? Basin origin & age? Depth? Southern Sputnik? Tidal evolution. Pluto Geophysics Answers to most of these questions needs an orbiter Sputnik Planitia Instruments: Gravity, Magnetometry, Sounding Radar, Thermal IR/Sub-mm Priority Science Question(s) Addressed 1. What were the initial stages, conditions, and processes of solar system formation and the nature of incorporated interstellar matter ? 6. Beyond Earth, are there contemporary habitats elsewhere in the solar system with necessary conditions, organic matter, water, energy, and nutrients to sustain life, and do organisms live there now? 9. Can understanding the roles of physics, chemistry, geology, and dynamics in driving planetary atmospheres and climates lead to a better understanding of climate change on Earth? Spencer et al., 2019 10. How have the myriad chemical and physical processes that shaped the solar system operated, interacted, and evolved over time? Hazes: Origin? Composition & structure? Properties of Pluto Atmosphere Atmospheric Gravity/Wave Propagation? Layering? Cthulhu? Climate: Seasonal Changes? Extremes? and Climate Escape: Why is the exosphere so cold? Answers to most of these questions needs an orbiter as most of these processes vary on the timescales of days-weeks to decades!!! Instruments: mass spec, sub-mm, UV spectroscopy/occultations, radio occultations, color cameras, plasma spectrometer and waves The atmosphere and surface are intimately linked! Therefore Surface Appearance and Climate in tight dance Priority Science Question(s) Addressed 4. What were the primordial sources of organic matter, and where does organic synthesis