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2019 Cool Sci @ STScI

Unlocking APL’s Interstellar Probe Mission Concept Study

Presented by: Kirby Runyon (JHU)
Category: Science Colloquia   Duration: 30 minutes   Broadcast date: January 30, 2019
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Abstract: The Interstellar Probe (IsP) spacecraft concept under study for NASA by APL would notionally launch in 2030 with a target of reaching a solar distance of 1000 AU in 50 years, leaving the Solar System at a speed of up to 20 AU per year. While the main science goal of IsP would be to study particles and fields of the interstellar environment, other opportunistic investigations could occur. Here, we will discuss the exploration potential for flybys of Kuiper Belt Objects (KBOs), especially small planets (D >~ 500 km). Potential spacecraft trajectories favor a flyby of Quaoar (D ~1110 km), with Ixion or Makemake as other potential, but less preferred targets due to their smaller sizes. Flying by KBO planets offers tantalizing possibilities for comparative planetology since Pluto, Charon, and Triton are the only other reconnoitered KBO planets to date. Geomorphological investigations of Quaoar’s surface landforms will be the most readily studied geological aspect of the planet, assuming IsP has imaging capability similar to New Horizons’ Long Range Reconnaissance Imager (LORRI). The types, distributions, and albedos of landforms on the encounter hemisphere will constrain their formation processes. The presence of crystalline volatile ices (e.g., CH4, C2H6, NH3-H2O) on Quaoar’s surface (Schaller and Brown, 2007; Barucci et al., 2015) suggests recent cryovolcanism and sublimation-driven surface geology with possibilities for aeolian processes and bedforms (dunes) and erosional yardangs. Higher-order hydrocarbons (e.g., tholins) from hydrocarbon photolysis would be more stable than methane (Schaller and Brown, 2007) and could form albedo patchworks, similar to Pluto. Observed crater size-frequency distributions would constrain the impactor flux population for heavily cratered terrains and show relative ages between geologic units. Crater ejecta emplacement mechanisms will be hinted at by the range of ejecta morphologies. Faults, pits, and bands will provide constraints on tectonic processes and may enable modeling of the interior, revealing if Quaoar ever had water in contact with hot rock, with astrobiological implications. Similar investigations of Quaoar’s moon, Weywot (D ~ 81 km), would also be possible. IR spectrometers or color imaging capability could augment geomorphology with compositional data.