Chimera: A Mission of Discovery to the First Centaur
Abstract
Chimera is a Discovery-class mission concept to explore the active, outbursting Centaur 29P/Schwassmann-Wachmann 1 (SW1). Centaurs are icy planetesimals perturbed from the Trans-Neptunian Object (TNO) population into unstable orbits between Jupiter and Neptune, from which a third migrate inward to become Jupiter Family Comets (JFCs). Their intermediate evolutionary state makes them a key bridge population between the TNOs and JFCs, with the ability to connect the observed characteristics of previous spacecraft targets. SW1 is the essential member of the Centaur group for scientific investigation, with properties uniquely able to transform our understanding of the origin and evolution of icy planetesimals. SW1 currently occupies an orbit just beyond Jupiter that recent dynamical models indicate is a short-lived gateway through which the majority of Centaurs pass just prior to their rebirth as JFCs. The characteristics of this orbit likely play a role in SW1's continuous activity, which is greater than any other Centaur and comparable to the great Comet Hale-Bopp at the same heliocentric distance. SW1 is the only small body known to experience major outbursts with a predictable frequency that can be matched to a spacecraft encounter. With chimeric properties that connect the evolutionary and active states of multiple small body classes, SW1 is the ideal target for addressing the multiple objectives for small bodies described in the 2013 Decadal Survey.
Chimera will deliver a suite of capable, high heritage imaging and spectroscopic instruments to explore SW1 on scales from the extended coma to deep interior. The mission has 5 primary objectives to; 1) Measure the abundances and properties of volatiles and grains, 2) Investigate the mechanisms of quiescent activity and outburst, 3) Survey the topography and composition of the surface, 4) Identify the presence and progress of evolutionary processes, and 5) to Probe near-surface and deep interior structures.- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.P34C..12H
- Keywords:
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- 6094 Instruments and techniques;
- PLANETARY SCIENCES: COMETS AND SMALL BODIES;
- 5794 Instruments and techniques;
- PLANETARY SCIENCES: FLUID PLANETS;
- 6297 Instruments and techniques;
- PLANETARY SCIENCES: SOLAR SYSTEM OBJECTS;
- 5494 Instruments and techniques;
- PLANETARY SCIENCES: SOLID SURFACE PLANETS