Rings and moons

  • Perspective
    | Open Access

    Vast, ancient impact basins scattered mantle materials across the lunar surface. We review lunar evolution models to identify candidate mantle lithologies, then assess orbital observations to evalutae the current distribution of these materials and implications for fundamental planetary processes.

    • Daniel P. Moriarty III
    • , Nick Dygert
    •  & Noah E. Petro
  • Article
    | Open Access

    In this study, the authors present a global map of rockfalls on the lunar surface and determine impact events as short- and long-term driver for rockfall events.

    • Valentin Tertius Bickel
    • , Jordan Aaron
    •  & Urs Mall
  • Article
    | Open Access

    The Chang’E-4 mission in January 2019 had the major challenge to land on the lunar far side without traditional radiometric techniques due to the missing line-of-sight. The authors here describe landing trajectory reconstruction and positioning techniques based upon the Moon’s digital terrain model that allowed reproducing the entire process of a successful landing.

    • Jianjun Liu
    • , Xin Ren
    •  & Weibin Wen
  • Article
    | Open Access

    Vicinity of small bodies might be dangerous to the spacecrafts and to their instrumentation. Here the authors show the operational environment of asteroid Bennu, validate its photometric phase function and demonstrate the accelerating rotational rate due to YORP effect using the data acquired during the approach phase of OSIRIS-REx mission.

    • C. W. Hergenrother
    • , C. K. Maleszewski
    •  & B. Marty
  • Article
    | Open Access

    Observations of Jupiter’s magnetosphere provide opportunities to understand how magnetic fields interact with particles. Here, the authors report that the chorus wave power is increased in the vicinity of Europa and Ganymede. The generated waves are able to accelerate particles to very high energy.

    • Y. Y. Shprits
    • , J. D. Menietti
    •  & D. A. Gurnett
  • Article
    | Open Access

    Many methanogenic archaea use H2 and CO2 to produce methane. Here, Taubner et al. show that Methanothermococcus okinawensis produces methane under conditions extrapolated for Saturn’s icy moon, Enceladus, and estimate that serpentinization may produce sufficient H2 for biological methane production.

    • Ruth-Sophie Taubner
    • , Patricia Pappenreiter
    •  & Simon K.-M. R. Rittmann
  • Article
    | Open Access

    The origin of the numerous linear grooves and craters that litter the Martian moon Phobos' surface remains enigmatic. Here, by modelling low-velocity escaping ejecta from impacts to Phobos, the authors show that several of these chains can be explained by reimpacting sesquinary ejecta shortly after ejection.

    • M. Nayak
    •  & E. Asphaug
  • Article
    | Open Access

    Recent samples have shown that the Moon's interior, previously thought to be anhydrous, contains water, yet how this water was delivered is unclear. Here, using isotopic analyses and modelling, Barnes et al. show that carbonaceous chondrite-type objects delivered >80% of the Moon's bulk water.

    • Jessica J. Barnes
    • , David A. Kring
    •  & Sara S. Russell
  • Article
    | Open Access

    Observations indicate that the southern hemisphere of Enceladus is geologically active, with spray containing Si nanoparticles being ejected from an underground ocean. Here, the authors report that experiments to constrain reaction conditions suggest the core is similar to that of carbonaceous chondrites.

    • Yasuhito Sekine
    • , Takazo Shibuya
    •  & Sin-iti Sirono
  • Article |

    Few high-pressure polymorphs have been found from lunar meteorites even though the moon has experienced heavy meteorite bombardment. This study presents evidence of a high-pressure polymorph of silica—seifertite—from a lunar meteorite; a record of an intense planetary collision on the moon ~2.7 Ga ago.

    • Masaaki Miyahara
    • , Shohei Kaneko
    •  & Naohisa Hirao
  • Article |

    The atmosphere of Titan, Saturn’s largest moon, consists of orange-yellow haze, but its formation and dynamics are not well understood. Here laboratory studies show that Titan’s lower atmosphere is photochemically active and the formation of complex prebiotic precursor molecules occurs at lower altitudes.

    • Murthy S. Gudipati
    • , Ronen Jacovi
    •  & Mark Allen