Planetary science

  • Article
    | Open Access

    Some regions on the Moon are permanently covered in shadow and are therefore extremely difficult to see into. We develop a deep learning driven algorithm which enhances images of these regions, allowing us to see inside them with high resolution for the first time.

    • V. T. Bickel
    • , B. Moseley
    •  & M. Shirley
  • Article
    | Open Access

    Ultramafic olivine-rich achondrites provide insight into the missing mantle problem in the asteroid belt. The petrology and geochemistry of these samples suggests they are related to Vesta or the Vestoids.

    • Zoltan Vaci
    • , James M. D. Day
    •  & Andreas Pack
  • Article
    | Open Access

    Lunar impact basins formed during the magma ocean solidification should have formed almost unidentifiable topographic and crustal thickness signatures, thus may escape detection. This result allows for a higher impact flux in the earliest epoch of Earth-Moon evolution.

    • K. Miljković
    • , M. A. Wieczorek
    •  & M. T. Zuber
  • Article
    | Open Access

    How early photosynthesizers managed oxidative stress remains relatively unresolved. Analyses of enzymes dealing with reactive oxygen species traces the evolutionary history of superoxide dismutases and finds evidence of CuZnSOD in the ancestor of all cyanobacteria, dating back to the Archaean.

    • Joanne S. Boden
    • , Kurt O. Konhauser
    •  & Patricia Sánchez-Baracaldo
  • 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

    The relative role of individual forcing events in long-term landscape evolution is challenging to measure in the field. Badlands offer special opportunities to quantify common, natural landscape dynamics on observational time scales.

    • Ci-Jian Yang
    • , Jens M. Turowski
    •  & Kuo-Jen Chang
  • Article
    | Open Access

    Meteorites from space often include denser polymorphs of their minerals, providing records of past hypervelocity collisions. An olivine mineral crystal was shock-compressed by a high-power laser, and its transformation into denser ringwoodite was time-resolved using an X-ray free electron laser.

    • Takuo Okuchi
    • , Yusuke Seto
    •  & Norimasa Ozaki
  • Article
    | Open Access

    Elevated Zn isotope compositions occur in K-Pg sedimentary layers of three different depositional environments across North America and the Caribbean. The data indicate a volatilization event, and act as a robust mechanistic indicator of the meteorite impact at the end of the Cretaceous.

    • Ryan Mathur
    • , Brandon Mahan
    •  & Francisca E. Oboh-Ikuenobe
  • Article
    | Open Access

    Arc olivines are commonly explained through a paradigm of core-to-rim sequential growth and oscillatory zoning is interpreted to represent magma mixing. Here the authors show Fo–Ni–P oscillatory zoned olivines can grow as out-of-sequence crystal frames and complex zoning can occur in closed systems.

    • Pablo Salas
    • , Philipp Ruprecht
    •  & Osvaldo Rabbia
  • Article
    | Open Access

    Gravity waves are observed in Venus atmosphere, but their characteristics are not well-known. Here, the authors show spontaneous generation of gravity waves from the thermal tides in the Venus atmosphere as small-scale gravity waves are resolved in high-resolution general circulation model.

    • Norihiko Sugimoto
    • , Yukiko Fujisawa
    •  & Yoshi-Yuki Hayashi
  • Article
    | Open Access

    Superbolts are powerful, rare lightning events. Here, the authors show simultaneous satellite and ground measurements of a superbolt, and demonstrate different properties of superbolts and lightnings.

    • J.-F. Ripoll
    • , T. Farges
    •  & S. Pédeboy
  • Article
    | Open Access

    Several scenarios exist to explain the origins of the organic matter found in carbonaceous chondrites. Here, the authors show laboratory experiments confirming that a significant portion of the soluble organic matter can originate from organic ices inherited from the dense molecular cloud.

    • G. Danger
    • , V. Vinogradoff
    •  & P. Schmitt-Kopplin
  • Article
    | Open Access

    Earth-system sensitivity (ESS) describes the long-term temperature response for a given change in atmospheric CO2 and, as such, is a crucial parameter to assess future climate change. Here, the authors use a Bayesian model with data from the last 420 Myrs to reduce uncertainties and estimate ESS to be around 3.4 °C.

    • Tony E. Wong
    • , Ying Cui
    •  & Klaus Keller
  • Article
    | Open Access

    The search for life in the universe is difficult due to issues with defining signatures of living systems. Here, the authors present an approach based on the molecular assembly number and tandem mass spectrometry that allows identification of molecules produced by biological systems, and use it to identify biosignatures from a range of samples, including ones from outer space.

    • Stuart M. Marshall
    • , Cole Mathis
    •  & Leroy Cronin
  • Article
    | Open Access

    Expanded phosphorus availability possibly triggered a marine bioproduction boom after 2.3 billion years ago, but its delivery mechanisms remain unclear. Here we propose a kaolinite shuttle which efficiently adsorbs phosphorus in continental weathering settings and releases it under marine conditions.

    • Weiduo Hao
    • , Kaarel Mänd
    •  & Kurt O. Konhauser
  • Article
    | Open Access

    Through platinum metal-silicate partitioning coefficient measurements, the authors here show that platinum partitioning into metal is lowered at high pressure–temperature conditions. This finding implies that the Earth’s mantle was likely enriched in platinum immediately following the core-mantle differentiation.

    • Terry-Ann Suer
    • , Julien Siebert
    •  & Guillaume Fiquet
  • Article
    | Open Access

    The evolution of multicellular life is hypothesized to have been promoted by rising oxygen levels. Through experimental evolution and modeling, Bozdag et al. demonstrate that our planet’s first oxygenation would have strongly constrained, not promoted, the evolution of multicellular life.

    • G. Ozan Bozdag
    • , Eric Libby
    •  & William C. Ratcliff
  • Article
    | Open Access

    The authors here propose a chemical reaction that forms ammoniated phyllosilicates on Ceres. This process could trigger at a very low temperature, suggesting Ceres evolution in a region different from its current location.

    • Santosh K. Singh
    • , Alexandre Bergantini
    •  & Ralf I. Kaiser
  • Article
    | Open Access

    The authors describe a dynamic surface instability between impacting materials, showing that a region of mixing grows between two media. The study implies that this can explain mixed compositions and textures in certain meteorites.

    • Avi Ravid
    • , Robert I. Citron
    •  & Raymond Jeanloz
  • Article
    | Open Access

    Polarimetry provides information about physical characteristics of cometary dust. Here, the authors show that the polarization of interstellar comet 2I/Borisov exceeds the typical values for comets, and this together with its polarimetrically homogenous coma suggests a more pristine nature of the object.

    • S. Bagnulo
    • , A. Cellino
    •  & M. Devogèle
  • Article
    | Open Access

    Here, the authors show that Earth and Moon are characterized by different vanadium isotope compositions, which is most likely resulting from vanadium isotope fractionation of the bulk silicate proto-Earth during the main stage of terrestrial core formation—followed by a canonical giant impact scenario, where 80% of the Moon originates from an impactor of chondritic composition.

    • Sune G. Nielsen
    • , David V. Bekaert
    •  & Maureen Auro
  • Article
    | Open Access

    Based on the analysis of chemical maps of Thorium and Potassium derived in the Eridania region on Mars, the authors show how radiogenic heat driven hydrothermal systems may have persisted on Mars.

    • Lujendra Ojha
    • , Suniti Karunatillake
    •  & Jacob Buffo
  • Article
    | Open Access

    Sunlight can change the composition of atmospheric aerosol particles, but the mechanisms through which this happens are not well known. Here, the authors show that fast radical reaction and slow diffusion near viscous organic particle surfaces can cause oxygen depletion, radical trapping and humidity dependent oxidation.

    • Peter A. Alpert
    • , Jing Dou
    •  & Markus Ammann
  • Article
    | Open Access

    Determining the origins of life on Earth is confounded by the fact that the sources of nutrients necessary to create early life forms remain mysterious. Here the authors show that lightning strikes could have supplied a major source of essential phosphorus on early Earth.

    • Benjamin L. Hess
    • , Sandra Piazolo
    •  & Jason Harvey
  • Article
    | Open Access

    The deglaciation of Marinoan snowball Earth (~635 Myr ago) has been associated with potentially extensive CH4 emissions in relation to transient marine euxinia. Here, the authors find that active methanogenesis occurred during the termination of Marinoan snowball Earth, fueled by methyl sulfide production in sulfidic seawater.

    • Zhouqiao Zhao
    • , Bing Shen
    •  & Haoran Ma
  • Article
    | Open Access

    Imaging of low-mass exoplanets can be achieved once the thermal background in the mid-infrared (MIR) wavelengths can be mitigated. Here, the authors present a ground-based MIR observing approach enabling imaging low-mass temperate exoplanets around nearby stars.

    • K. Wagner
    • , A. Boehle
    •  & T. de Zeeuw
  • Article
    | Open Access

    The authors report in-situ formation of jarosite witin the Talos Dome ice core (East Antarctica) and show that this ferric-potassium sulfate mineral is present in ice deeper than 1000 meters and progressively increases with depth. This has implications for the presence and formation mechanisms of jarosite observed on Mars.

    • Giovanni Baccolo
    • , Barbara Delmonte
    •  & Massimo Frezzotti
  • Article
    | Open Access

    Wildfires produce aerosols known to impact the climate, but the wider-reaching effects of this biomass burning are poorly constrained in models. Here the authors use a suite of observations from 12 campaigns around the globe to determine that the values used by most climate models overestimate the contribution of biomass burning aerosols.

    • Hunter Brown
    • , Xiaohong Liu
    •  & Duli Chand
  • Article
    | Open Access

    This manuscript tackles the origin of organic molecules in carbonaceous meteorites. Identifying hexamethylenetetramine in three carbonaceous meteorites, the authors propose formation from ammonia and formaldehyde by photochemical and thermal reactions in the interstellar medium, followed by the incorporation into planetary systems.

    • Yasuhiro Oba
    • , Yoshinori Takano
    •  & Shogo Tachibana
  • Article
    | Open Access

    In the habitable zone concept, a planet’s carbon dioxide-water greenhouse maintains surface liquid water. Here, the authors estimate how many Earthlike exoplanets are needed to detect a relationship between stellar flux and the atmospheric carbon dioxide predicted by carbon cycle modeling.

    • Owen R. Lehmer
    • , David C. Catling
    •  & Joshua Krissansen-Totton
  • Article
    | Open Access

    Establishing diagnostics for terrestrial exoplanets are crucial for their characterization. Here, the authors show brightness modulations of Venus are caused by planetary-scale waves superimposed on the super-rotating winds can be used to detect existence of an atmosphere if detected at an exoplanet.

    • Y. J. Lee
    • , A. García Muñoz
    •  & S. Watanabe
  • Article
    | Open Access

    Rare earth elements are used in electronics, but increase in demand could lead to low supply. Here the authors conduct experiments on the International Space Station and show microbes can extract rare elements from rocks at low gravity, a finding that could extend mining potential to other planets.

    • Charles S. Cockell
    • , Rosa Santomartino
    •  & René Demets
  • Article
    | Open Access

    The abnormally low concentration of xenon compared to other noble gases in Earth’s atmosphere remains debated, as the identification of mantle minerals that can capture and stabilize xenon is challenging. Here, the authors propose that xenon iron oxides could be potential Xe hosts in Earth’s lower mantle.

    • Feng Peng
    • , Xianqi Song
    •  & Yanming Ma
  • Article
    | Open Access

    Transport properties of melts in the deep Earth have dictated the evolution of the early Earth’s magma oceans and also govern many modern dynamic processes, such as plate tectonics. Here, the authors find there is a reversal in the trends of transport properties of basaltic melts at pressures near 50 GPa, with implications for the timescales of early Earth’s magma oceans.

    • Arnab Majumdar
    • , Min Wu
    •  & John S. Tse
  • Article
    | Open Access

    Calcium and oxygen are abundant elements in the Earth’s mantle, largely present as calcium oxide. Here the authors show, by experiments and computations, that calcium ozonide (CaO3) is stabilized at the high pressures and temperatures characteristic of the lower mantle, with implications for the deep Earth’s chemistry.

    • Yanchao Wang
    • , Meiling Xu
    •  & Yanming Ma
  • Article
    | Open Access

    The second extended phase of the Dawn mission provided high resolution observations of Occator crater of the dwarf planet Ceres. Here, the authors show that the central faculae were sourced in an impact-induced melt chamber, with a contribution from the deep brine reservoir, while the Vinalia Faculae were sourced by the deep brine reservoir alone.

    • J. E. C. Scully
    • , P. M. Schenk
    •  & C. T. Russell
  • Article
    | Open Access

    Dawn mission’s second extended phase provided high resolution observations of Occator crater of the dwarf planet Ceres. Here, the authors show stereo imaging and topographic maps of this crater revealing the influence of crustal composition on impact related melt and hydrothermal processes, and compare features to those on Mars, Earth and the Moon.

    • P. Schenk
    • , J. Scully
    •  & C. Raymond