This review focuses on the rapidly growing field of natural 238U/235U variability, largely
driven by the technical advances in the measurement of U isotope ratios by mass …

Isotopic variations usually follow mass-dependent fractionation, meaning that the relative
variations in isotopic ratios scale with the difference in mass of the isotopes involved (eg …

Half of the chemical elements heavier than iron are produced by the rapid neutron capture
process (r-process). The sites and yields of this process are disputed, with candidates …

The origin of cometary matter and the potential contribution of comets to inner-planet
atmospheres are long-standing problems. During a series of dedicated low-altitude orbits …

Neutron star mergers have been long considered as promising sites of heavy r-process
nucleosynthesis. We overview the observational evidence supporting this scenario …

The heaviest chemical elements are naturally produced by the rapid neutron-capture
process (r-process) during neutron star mergers or supernovae. The r-process production of …

In addition to long-lived radioactive nuclei like U and Th isotopes, which have been used to
measure the age of theGalaxy, also radioactive nuclei with half-lives between 0.1 and 100 …

Uranium isotope ratios are widely utilized in paleoceanography. The 238 U/235 U ratio
(expressed as δ 238 U) is leveraged as a proxy for the areal extent of anoxic seafloor, and …

Abstract Northwest Africa (NWA) 6704/6693 are medium-to coarse-grained achondrites with
unique petrologic and geochemical traits that are distinct from the currently established …

Significant uranium (U) isotope fractionation has been observed during abiotic reduction of
aqueous U, counter to the expectation that uranium isotopes are only fractionated by …