In situ research of cometary chemistry began when measurements from the Giotto mission at
Comet 1P/Halley revealed the presence of complex organics in the coma. New telescopes …

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 …

Hydrogen is one of the possible alloying elements in the Earth's core, but its siderophile
(iron-loving) nature is debated. Here we experimentally examined the partitioning of …

Determining the source (s) of hydrogen, carbon, and nitrogen accreted by Earth is important
for understanding the origins of water and life and for constraining dynamical processes that …

We present a comprehensive evolutionary model of the Sun's protoplanetary disk,
constructed to resolve the" CAI storage problem" of meteoritics. We predict the abundances …

The delivery of water to the inner Solar System, including Earth, is still a debated topic. A
preferential role for hydrated asteroids in this process is supported by isotopic …

The Hayabusa2 spacecraft explored asteroid Ryugu and brought its surface materials to
Earth. Ryugu samples resemble Ivuna-type (CI) chondrites—the most chemically primitive …

Earth and the Moon are shown here to have indistinguishable oxygen isotope ratios, with a
difference in Δ′ 17O of− 1±5 parts per million (2 standard error). On the basis of these data …

All planetary materials sampled thus far vary in their relative abundance of the major isotope
of oxygen, 16O, such that it has not been possible to define a primordial solar system …

Samples from asteroid Ryugu returned by the Hayabusa2 mission contain evidence of
extensive alteration by aqueous fluids and appear related to the CI chondrites. To …