Results 51 to 60 of about 3,693 (177)

New knowledge about shock events that affected the L‐chondrite parent body from two heavily shocked L6 meteorite finds

Meteoritics &Planetary Science, EarlyView.
Abstract We report new results from a study of shock‐related features in the L6 ordinary chondrites Northwest Africa (NWA) 4672 and NWA 12841. Our observations confirm the occurrence of eight high‐pressure (HP) minerals in each meteorite, namely, ringwoodite, majorite, akimotoite, wadsleyite, albitic jadeite, lingunite, tuite, and xieite.
I. Baziotis, L. Ferrière, C. Ma, J. Hu, D. Palles, P. D. Asimow   +5 more
wiley   +1 more source

Determination of Orbital Elements and Ephemerides using the Geocentric Laplace’s Method

Journal of Astronomy and Space Sciences, 2020
This paper presents a methodology for Initial Orbit Determination (IOD) based on a modification of the Laplace’s geocentric method. The orbital elements for Near-Earth asteroids (1864) Daedalus, 2003 GW, 2019 JA8, a Hungaria-type asteroid (4690 ...
Daniela Espitia, Edwin A. Quintero, Ivan D. Arellano-Ramírez   +2 more
doaj   +1 more source

Measuring the Orbit Drift of Near-Earth Asteroids by the Yarkovsky Effect

The Astrophysical Journal, 2023
The Yarkovsky effect causes the semimajor axis drift of near-Earth asteroids. The drift can be detected by a precise orbit determination process. Using the proposed algorithm, 2233 out of 27,078 near-Earth asteroids are chosen as the initial candidates ...
Xin Liu, Xi-Yun Hou, Zhi-Tao Yang, Qing-Bo Gan, Yao Zhang   +4 more
doaj   +1 more source

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

Apatite in Bennu samples indicates multiple stages of aqueous alteration

Meteoritics &Planetary Science, EarlyView.
Abstract Calcium phosphates are ubiquitous in planetary materials, including samples returned from asteroid Bennu by the OSIRIS‐REx mission. We characterized apatite [Ca5(PO4)3(F,Cl,OH)] grains in Bennu samples by scanning electron microscopy, electron microprobe analysis, and transmission electron microscopy to investigate their compositions, mineral ...
Laura B. Seifert, T. M. Erickson, L. P. Keller, J. J. Barnes, K. Thomas‐Keprta, L. Le, J. Gorce, Z. Rahman, T. J. Zega, H. C. Connolly Jr, D. S. Lauretta   +10 more
wiley   +1 more source

Asteroid Mass Estimation by Mutual Perturbations During Close Encounters After Gaia Focused Product Release

The Astronomical Journal
Mutual perturbations between asteroids during close encounters allow the estimation of their masses using precise astrometric observations. We use all astrometry reported to the Minor Planet Center, high-precision astrometry from ESA’s Gaia Focused ...
Oscar Fuentes-Muñoz, Davide Farnocchia, Jon D. Giorgini, Ryan S. Park   +3 more
doaj   +1 more source

Static recrystallization of shocked calcite in Ries impact breccias

Meteoritics &Planetary Science, EarlyView.
Abstract Calcite is prone to chemical and microstructural modifications, especially after having been strained at high stresses and strain rates, as during hypervelocity impact events. These modifications include precipitation from pore fluid as well as replacement of strained volumes by recrystallization. In calcite aggregates of a metagranite breccia
Claudia A. Trepmann, Fabian Dellefant, Lina Seybold, Wolfgang W. Schmahl, Elena Sturm, Daniel Weidendorfer, Sandro Jahn, Iuliia V. Sleptsova, Stuart A. Gilder   +8 more
wiley   +1 more source

Infrared Colors of Small Serendipitously Found Asteroids in the UKIRT Hemisphere Survey

The Astronomical Journal
The UKIRT Hemisphere Survey covers the northern sky in the infrared from 0° to 60° decl. Current data releases include both J and K bands, with H -band data forthcoming. Here, we present a novel pipeline to recover asteroids from this survey data.
Samantha G. Morrison, Ryder H. Strauss, David E. Trilling, Andy J. López-Oquendo, Justice Bruursema, Frederick J. Vrba   +5 more
doaj   +1 more source

Photometry and Models of Seven Main-Belt Asteroids

Universe
The China Near-Earth Object Survey Telescope (CNEOST) conducted four photometric surveys from 2015 to 2018 using image processing and aperture photometry techniques to obtain extensive light curve data on asteroids. The second-order Fourier series method
Jun Tian, Haibin Zhao, Bin Li, Yongxiong Zhang, Jian Chen, Leonid Elenin, Xiaoping Lu   +6 more
doaj   +1 more source

Geochemical and petrographic re‐evaluation of ungrouped iron meteorites from Western Australia

Meteoritics &Planetary Science, EarlyView.
Abstract Under the current classification scheme, ungrouped irons make up ~11% of all recognized iron meteorites. A further ~7% of iron meteorites are currently classified as simply “irons” and are yet to be fully classified. To potentially classify these meteorites, newer approaches, including either statistical modeling or advanced geochemical ...
Ashley Rogers, Lucy Forman, Kai Rankenburg, Rachel Kirby, Martin Danišík, Victoria Cousins, Gretchen K. Benedix   +6 more
wiley   +1 more source