Results 31 to 40 of about 813 (198)

Noble gases and nitrogen in material from asteroid Bennu

Meteoritics &Planetary Science, EarlyView.
Abstract We report the elemental and isotopic abundances of all stable noble gases (helium, neon, argon, krypton, and xenon) in eight particles from asteroid Bennu returned by NASA's OSIRIS‐REx mission. We also report nitrogen abundances and isotopic ratios that were analyzed alongside neon and argon in four additional Bennu particles.
B. Marty, L. Zimmermann, E. Füri, D. V. Bekaert, J. J. Barnes, A. N. Nguyen, H. C. Connolly, D. S. Lauretta   +7 more
wiley   +1 more source

Initial study of regolith exposure ages and burial conditions on Ryugu: Cosmogenic nuclides score in two touchdowns

Meteoritics &Planetary Science, EarlyView.
Abstract Surface processes on the asteroid Ryugu have been investigated using cosmic‐ray‐produced radionuclides, 10Be, 26Al, and 36Cl, and stable noble gases, on eight samples returned by the Hayabusa2 spacecraft. The 10Be and 26Al along with 21Ne measurements indicate that the two Chamber A samples A0105 collected during the first touchdown (TD) were ...
Kunihiko Nishiizumi, Keisuke Nagao, Marc W. Caffee, Ryuji Okazaki, Jozef Masarik, Hisayoshi Yurimoto, Tomoki Nakamura, Takaaki Noguchi, Hiroshi Naraoka, Hikaru Yabuta, Kanako Sakamoto, Kasumi Yogata, Toru Yada, Shogo Tachibana, Sei‐ichiro Watanabe, Yuichi Tsuda, Masanao Abe, Kazuya Kumagai, Akiko Miyazaki, Aiko Nakato, Satoru Nakazawa, Masahiro Nishimura, Tatsuaki Okada, Takanao Saiki, Hirotaka Sawada, Satoshi Tanaka, Tomohiro Usui, Koji Wada, Hajime Yano, Makoto Yoshikawa, Hayabusa2 Initial Analysis Volatile Team   +30 more
wiley   +1 more source

Petrography and mineral chemistry of Northeast Africa 053—A remnant of Martian crystal mush

Meteoritics &Planetary Science, EarlyView.
Abstract In Earth's igneous systems, crystal mushes, crystal‐rich frameworks permeated by silicate melt, represent a common and fundamental stage in the evolution of magma bodies. However, whether crystal mushes occur within Martian igneous systems and play a comparable role is unknown. Here, we present a comprehensive petrography and mineral chemistry
Xhonatan Shehaj, Eleonora Ammannito, Giovanni Pratesi   +2 more
wiley   +1 more source

Identification of Multiscale Spatial Structure of Lunar Impact Crater: A Semivariogram Approach

IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, 2021
Identifying the spatial structure of lunar impact craters is necessary to increase our understanding of past geologic processes on the Moon. However, detecting multiscale spatial structures of craters in images in appropriate resolutions using optimum ...
Jiao Wang, Dongping Ming, Weiming Cheng
doaj   +1 more source

Model Calculations for Cosmogenic Nuclides in Meteorites and the Lunar Surface. 1. Long‐lived Radionuclides

Meteoritics &Planetary Science, EarlyView.
Abstract Production rates for the cosmogenic radionuclides 10Be, 14C, 26Al, 36Cl, 41Ca, 53Mn, and 60Fe in a large variety of meteorites, that is, ordinary chondrites (H, L, LL), carbonaceous chondrites, HED meteorites, ureilites, Martian meteorites, and iron meteorites and in the uppermost ~2 m of the lunar surface are modeled.
Ingo Leya
wiley   +1 more source

Robust Crater Detection Algorithm Based on Maximum Entropy Threshold Segmentation

International Journal of Aerospace Engineering, 2022
For future lunar exploration and planetary missions, the digital elevation model (DEM) of the target object may not be well prepared before the mission, so developing a new robust crater detection algorithm (CDA) without prepared high-precision DEM is ...
Peng Wu, Rongjun Mu, Yanpeng Deng
doaj   +1 more source

Self-Secondaries Formed by Cold Spot Craters on the Moon

Remote Sensing, 2021
Self-secondaries are a population of background secondaries, and they have been observed on top of impact melt and ballistically emplaced ejecta deposits on various planetary bodies.
Yiren Chang, Zhiyong Xiao, Yang Liu, Jun Cui   +3 more
doaj   +1 more source

Microspherules Formed by Lightning Strikes

Meteoritics &Planetary Science, EarlyView.
Abstract Natural microspherules are formed by high‐temperature processes and are present throughout the geologic record to the present day. We report the discovery of large numbers of microspherules recovered from a rock pavement in the Pilbara region, Western Australia.
M. R. Boyd, M. J. Genge, A. G. Tomkins
wiley   +1 more source

YOLO-SCNet: A Framework for Enhanced Detection of Small Lunar Craters

Remote Sensing
The study of impact craters is crucial for understanding planetary evolution and geological processes, particularly small craters, which are key to reconstructing the lunar impact history. Detecting small craters, with diameters ranging from 0.2 to 2 km,
Wei Zuo, Xingye Gao, Di Wu, Jiaqian Liu, Xingguo Zeng, Chunlai Li   +5 more
doaj   +1 more source

AUTOMATIC DETECTION AND RECOGNITION OF CRATERS BASED ON THE SPECTRAL FEATURES OF LUNAR ROCKS AND MINERALS [PDF]

The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, 2017
Crater-detection approaches can be divided into four categories: manual recognition, shape-profile fitting algorithms, machine-learning methods and geological information-based analysis using terrain and spectral data.
L. Ye, X. Xu, D. Luan, W. Jiang, Z. Kang
doaj   +1 more source