Results 131 to 140 of about 121,017 (322)

Surface composition and taxonomic classification of a group of near-Earth and Mars-crossing asteroids

open access: yes, 2013
In the past, constraining the surface composition of near-Earth asteroids (NEAs) has been difficult due to the lack of high quality near-IR spectral data (0.7-2.5 microns) that contain mineralogically diagnostic absorption bands. Here we present visible (
Michelsen, René   +3 more
core   +1 more source

Magnesium phosphate in the Cold Bokkeveld (CM2) carbonaceous chondrite

open access: yesMeteoritics &Planetary Science, EarlyView.
Abstract Hydrous Mg‐phosphate was first described from astromaterials in particles returned from the C‐type asteroid Ryugu, and has subsequently been found in samples of the B‐type asteroid Bennu and CI1 carbonaceous chondrites. This phase may have been highly significant as a source of bioessential compounds for early Earth.
Martin R. Lee   +2 more
wiley   +1 more source

Some Studies of Terrestrial Impact Cratering Rate

open access: yesOpen Astronomy, 2011
In 1984, a 28.4 Myr periodicity was detected in the ages of terrestrial impact craters and a 26 Myr periodicity in the epochs of mass extinctions of species.
Jetsu L.
doaj   +1 more source

Identification of Magnetite in B-type Asteroids

open access: yes, 2010
Spectrally blue (B-type) asteroids are rare, with the second discovered asteroid Pallas being the largest and most famous example. We conducted a focused, infrared spectroscopic survey of B-type asteroids to search for water-related features in these ...
Adams   +32 more
core   +1 more source

Matera: A not so ordinary H5 chondrite breccia with very low density and high porosity

open access: yesMeteoritics &Planetary Science, EarlyView.
Abstract On the evening of February 14, 2023, at 17:58 UT, a fireball was detected by three cameras of the Italian PRISMA network (FRIPON network). The first samples of the Matera meteorite, collected 3 days after the fall, lay on the balcony of a private home.
Giovanni Pratesi   +27 more
wiley   +1 more source

Asteroid Models from Multiple Data Sources

open access: yes, 2015
In the past decade, hundreds of asteroid shape models have been derived using the lightcurve inversion method. At the same time, a new framework of 3-D shape modeling based on the combined analysis of widely different data sources such as optical ...
Carry, B.   +4 more
core   +1 more source

Expected value, to a point: Moral decision‐making under background uncertainty

open access: yesNoûs, EarlyView.
Abstract Expected value maximization gives plausible guidance for moral decision‐making under uncertainty in many situations. But it has unappetizing implications in ‘Pascalian’ situations involving tiny probabilities of extreme outcomes. This paper shows, first, that under realistic levels of ‘background uncertainty’ about sources of value independent
Christian Tarsney
wiley   +1 more source

Modeling Binary Asteroids: Integrating Orbital and Rotational Motion for Physical Property Inversion

open access: yesThe Astrophysical Journal
The field of space science places significant emphasis on deep space exploration, with a particular focus on asteroids as a potential hazard to humanity.
Xiao-Ping Lu   +4 more
doaj   +1 more source

Photoluminescence and Cathodoluminescence of the Solid Cometary Substance

open access: yesOpen Astronomy, 2019
We have proposed that solar ultraviolet and corpuscular radiations may excite photoluminescence and cathodoluminescence of the solid cometary substance including mineral halos of comets.
Simonia Irakli, Gucsik Arnold
doaj   +1 more source

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