Accepted Manuscript, The Planetary Science Journal Pre-print 1 The Lunar Geophysical Network Landing Sites Science Rationale Heidi Fuqua Haviland 1 2 , Renee C. Weber 2 , Clive R. Neal 3 , Philippe Lognonné 4 , Raphaël F. Garcia 5 , Nicholas Schmerr 6 , Seiichi Nagihara 7 , Robert Grimm 8 , Douglas G. Currie 6 , Simone Dell'Agnello 9 , Thomas R. Watters 10 , Mark P. Panning 11 , Catherine L. Johnson 12 13 , Ryuhei Yamada 14 , Martin Knapmeyer 15 , Lillian R. Ostrach 16 17 , Taichi Kawamura 4 , Noah Petro 18 , Paul M. Bremner 2 Abstract The Lunar Geophysical Network (LGN) mission is proposed to land on the Moon in 2030 and deploy packages at four locations to enable geophysical measurements for 6-10 years. Returning to the lunar surface with a long-lived geophysical network is a key next step to advance lunar and planetary science. LGN will greatly expand our primarily Apollo-based knowledge of the deep lunar interior by identifying and characterizing mantle melt layers, as well as core size and state. To meet the mission objectives, the instrument suite provides complementary seismic, geodetic, heat flow, and electromagnetic observations. We discuss the network landing site requirements and provide example sites that meet these requirements. Landing site selection will continue to be optimized throughout the formulation of this mission. Possible sites include the P- 5 region within the Procellarum KREEP Terrane (PKT; (lat:15˚; long:-35˚), Schickard Basin (lat:-44.3˚; long:-55.1˚), Crisium Basin (lat:18.5˚; long:61.8˚), and the farside Korolev Basin (lat:-2.4˚; long:-159.3˚). Network optimization considers the best locations to observe seismic core phases, e.g., ScS and PKP. Ray path density and proximity to young fault scarps are also analyzed to provide increased opportunities for seismic observations. Geodetic constraints require the network to have at least three nearside stations at maximum limb distances. Heat flow and electromagnetic measurements should be obtained away from terrane boundaries and from magnetic anomalies at locations representative of global trends. An in-depth case study is 1 Corresponding author: heidi.haviland@nasa.gov 2 NASA Marshall Space Flight Center, Heliophysics and Planetary Science Branch, 320 Sparkman Ave, NSSTC/2070, Huntsville, AL 35820 3 University of Notre Dame, Dept. Civil & Env. Eng. & Earth Sciences 4 Université de Paris, Institut de physique du globe de Paris, CNRS, F75005 Paris. 5 ISAE-SUPAERO, 10 ave E. Belin F-31400 Toulouse, France 6 University of Maryland at College Park 7 Texas Tech University 8 Southwest Research Institute 9 Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Frascati (INFN-LNF), Frascati, Italy 10 Center for Earth and Planetary Studies of the National Air and Space Museum, Smithsonian Institution, Washington, DC 20560, USA 11 NASA Jet Propulsion Lab 12 Department of Earth, Ocean and Atmospheric Sciences, University of British Columbia, Vancouver, British Columbia, Canada 13 Planetary Science Institute, Tucson, AZ, USA 14 Aizu University, Japan 15 DRL, Berlin, Germany 16 U.S. Geological Survey, Astrogeology Science Center 17 “This draft manuscript is distributed solely for purposes of scientific peer review. Its content is deliberative and predecisional, so it must not be disclosed or released by reviewers. Because the manuscript has not yet been approved for publication by the U.S. Geological Survey (USGS), it does not represent any official USGS finding or policy." 18 NASA Goddard Space Flight Center, Greenbelt, MD 20771