A Multispecies Pseudoadiabat for Simulating Condensable-rich Exoplanet Atmospheres

The Planetary Science Journal American Astronomical Society 2:5 (2021) 207-207

Authors:

RJ Graham, Tim Lichtenberg, Ryan Boukrouche, Raymond T Pierrehumbert

Lucy mission to the Trojan asteroids: Science goals

Planetary Science Journal 2:5 (2021)

Authors:

HF Levison, CB Olkin, KS Noll, S Marchi, JF Bell, E Bierhaus, R Binzel, W Bottke, D Britt, M Brown, M Buie, P Christensen, J Emery, W Grundy, VE Hamilton, C Howett, S Mottola, M Pätzold, D Reuter, J Spencer, TS Statler, SA Stern, J Sunshine, H Weaver, I Wong

Abstract:

The Lucy Mission is a NASA Discovery-class mission to send a highly capable and robust spacecraft to investigate seven primitive bodies near both the L4 and L5 Lagrange points with Jupiter: the Jupiter Trojan asteroids. These planetesimals from the outer planetary system have been preserved since early in solar system history. The Lucy mission will fly by and extensively study a diverse selection of Trojan asteroids, including all the recognized taxonomic classes, a collisional family member, and a near equal-mass binary. It will visit objects with diameters ranging from roughly 1 km to 100 km. The payload suite consists of a color camera and infrared imaging spectrometer, a high-resolution panchromatic imager, and a thermal infrared spectrometer. Additionally, two spacecraft subsystems will also contribute to the science investigations: the terminal tracking cameras will supplement imaging during closest approach and the telecommunication subsystem will be used to measure the mass of the Trojans. The science goals are derived from the 2013 Planetary Decadal Survey and include determining the surface composition, assessing the geology, determining the bulk properties, and searching for satellites and rings.

Lucy mission to the Trojan asteroids: Instrumentation and encounter concept of operations

Planetary Science Journal 2:5 (2021)

Authors:

CB Olkin, HF Levison, M Vincent, KS Noll, J Andrews, S Gray, P Good, S Marchi, P Christensen, D Reuter, H Weaver, M Pätzold, JF Bell, VE Hamilton, ND Russo, A Simon, M Beasley, W Grundy, C Howett, J Spencer, M Ravine, M Caplinger

Abstract:

The Lucy Mission accomplishes its science during a series of five flyby encounters with seven Trojan asteroid targets. This mission architecture drives a concept of operations design that maximizes science return, provides redundancy in observations where possible, features autonomous fault protection, and utilizes onboard target tracking near closest approach. These design considerations reduce risk during the relatively short time-critical periods when science data is collected. The payload suite consists of a color camera and infrared imaging spectrometer, a high-resolution panchromatic imager, and a thermal infrared spectrometer. The mission design allows for concurrent observations of all instruments. Additionally, two spacecraft subsystems will also contribute to the science investigations: the Terminal Tracking Cameras will obtain wide field-of-view imaging near closest approach to determine the shape of each of the Trojan targets and the telecommunication subsystem will carry out Doppler tracking of the spacecraft to determine the mass of each of the Trojan targets.

Tracing the earliest stages of hydrothermal alteration on the CM chondrite parent body

METEORITICS & PLANETARY SCIENCE 56:9 (2021) 1708-1728

Authors:

AJ King, E Mason, HC Bates, PF Schofield, KL Donaldson Hanna, NE Bowles, SS Russell

Science goals and objectives for the dragonfly titan rotorcraft relocatable lander

Planetary Science Journal 2:4 (2021)

Authors:

JW Barnes, EP Turtle, MG Trainer, RD Lorenz, SM MacKenzie, WB Brinckerhoff, ML Cable, CM Ernst, C Freissinet, KP Hand, AG Hayes, SM Hörst, JR Johnson, E Karkoschka, DJ Lawrence, AL Gall, JM Lora, CP McKay, RS Miller, SL Murchie, CD Neish, CE Newman, J Núñez, MP Panning, AM Parsons, PN Peplowski, LC Quic, J Radebaugh, SCR Rafkin, H Shiraishi, JM Soderblom, KS Sotzen, AM Stickle, ER Stofan, C Szopa, T Tokano, T Wagner, C Wilson, RA Yingst, K Zacny2, SC Stähler

Abstract:

NASA's Dragonfly mission will send a rotorcraft lander to the surface of Titan in the mid-2030s. Dragonfly's science themes include investigation of Titan's prebiotic chemistry, habitability, and potential chemical biosignatures from both water-based "life as we know it" (as might occur in the interior mantle ocean, potential cryovolcanic flows, and/or impact melt deposits) and potential "life, but not as we know it" that might use liquid hydrocarbons as a solvent (within Titan's lakes, seas, and/or aquifers). Consideration of both of these solvents simultaneously led to our initial landing site in Titan's equatorial dunes and interdunes to sample organic sediments and water ice, respectively. Ultimately, Dragonfly's traverse target is the 80 km diameter Selk Crater, at 7° N, where we seek previously liquid water that has mixed with surface organics. Our science goals include determining how far prebiotic chemistry has progressed on Titan and what molecules and elements might be available for such chemistry. We will also determine the role of Titan's tropical deserts in the global methane cycle. We will investigate the processes and processing rates that modify Titan's surface geology and constrain how and where organics and liquid water can mix on and within Titan. Importantly, we will search for chemical biosignatures indicative of past or extant biological processes. As such, Dragonfly, along with Perseverance, is the first NASA mission to explicitly incorporate the search for signs of life into its mission goals since the Viking landers in 1976 2021. The Author(s). Published by the American Astronomical Society.