Exoplanets in our Backyard 2020 (LPI Contrib. No. 2195) 3015.pdf TITAN: A HAZY WATERWORLD THAT WE CAN VISIT Jason W. Barnes1, Elizabeth P. Turtle2, Melissa G. Trainer3, Ralph D. Lorenz2, Sarah Horst¨ 4, Shannon M. MacKenzie2, and the Dragonfly Science Team. 1University of Idaho, Moscow, ID, USA (
[email protected]), 2Johns Hopkins Applied Physics Laboratory, Laurel, MD, USA, 3NASA Goddard Space Flight Center, Greenbelt, MD, USA, 4Johns Hopkins University, Baltimore, Maryland, USA 1 INTRODUCTION There are precious few examples of planets with both distinct surfaces and thick atmospheres in the Solar Sys- tem: just Venus, Earth, Mars, and Saturn’s moon Titan. These four therefore represent our only opportunities to explore close-up the diversity of physical and chemical processes that we expect occur on trillions of extrasolar planets in the Milky Way. Titan’s contributions to this endeavor derive from its (1) organic chemistry, (2) in- terior water ocean, (3) surface-atmosphere interactions, and (4) hazy methane-rich atmosphere. Titan’s particular strength with respect to exoplan- Figure 1: Artist’s conception of Dragonfly on the surface of Titan, ets derives from its accessibility. The Cassini/Huygens within an interdune in the Shangri-La sand sea. mission explored Titan from Saturn orbit and within the atmosphere, respectively. A future Titan orbiter mission will hopefully follow up on Cassini’s discoveries [e.g. 1], periment in abiotic organic synthesis. Entire planets like providing global imaging and topography, atmospheric Titan may be common in extrasolar systems [3, 4, 5]. measurements and characterization, and gravity probing On Titan, carbon can interact with liquid water on of the interior.