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Organic matter in meteorites reveals clues about early Solar System chemistry and the origin of molecules important to life, but terrestrial exposure complicates interpretation. Samples returned from the B-type asteroid Bennu by the Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer mission enabled us to study pristine carbonaceous astromaterial without uncontrolled exposure to Earth's biosphere. Here we show that Bennu samples are volatile rich, with more carbon, nitrogen and ammonia than samples from asteroid Ryugu and most meteorites. Nitrogen-15 isotopic enrichments indicate that ammonia and other N-containing soluble molecules formed in a cold molecular cloud or the outer protoplanetary disk. We detected amino acids (including 14 of the 20 used in terrestrial biology), amines, formaldehyde, carboxylic acids, polycyclic aromatic hydrocarbons and N-heterocycles (including all five nucleobases found in DNA and RNA), along with ~10,000 N-bearing chemical species. All chiral non-protein amino acids were racemic or nearly so, implying that terrestrial life's left-handed chirality may not be due to bias in prebiotic molecules delivered by impacts. The relative abundances of amino acids and other soluble organics suggest formation and alteration by low-temperature reactions, possibly in NH 3 -rich fluids. Bennu's parent asteroid developed in or accreted ices from a reservoir in the outer Solar System where ammonia ice was stable., Competing Interests: Competing interestsThe authors declare no competing interests., (© This is a U.S. Government work and not under copyright protection in the US; foreign copyright protection may apply 2025.)

From ancient sea species to clues on comets, papers by the country’s talented scientists are regularly making headlines. [ABSTRACT FROM AUTHOR]

The space rock — possibly the exposed core of a planet that didn’t finish forming — could reveal details about the Solar System’s origins. [ABSTRACT FROM AUTHOR]

Pluto's surface is dominated by the huge, pear-shaped basin Sputnik Planitia. It appears to be of impact origin, but modelling has not yet explained its peculiar geometry. We propose an impact mechanism that reproduces its topographic shape while also explaining its alignment near the Pluto-Charon axis. Using three-dimensional hydrodynamic simulations to model realistic collisions, we provide a hypothesis that does not rely upon a cold, stiff crust atop a contrarily liquid ocean where a differentiated ~730 km ice-rock impactor collides at low-velocity into a subsolidus Pluto-like target. The result is a new geologic region dominated by impactor material, namely a basin that (in a 30° collision) closely reproduces the morphology of Sputnik Planitia, and a captured rocky impactor core that has penetrated the ice to accrete as a substantial, strength-supported mascon. This provides an alternative explanation for Sputnik Planitia's equatorial alignment and illustrates a regime in which strength effects, in low-velocity collisions between trans-Neptunian objects, lead to impactor-dominated regions on the surface and at depth., Competing Interests: Competing interestsThe authors declare no competing interests., (© The Author(s) 2024.)

Near-Earth asteroid, Kamo'oalewa (469219), is one of a small number of known quasi-satellites of Earth; it transitions between quasi-satellite and horseshoe orbital states on centennial timescales, maintaining this dynamics over megayears. The similarity of its reflectance spectrum to lunar silicates and its Earth-like orbit both suggest that it originated from the lunar surface. Here we carry out numerical simulations of the dynamical evolution of particles launched from different locations on the lunar surface with a range of ejection velocities in order to assess the hypothesis that Kamo'oalewa originated as a debris-fragment from a meteoroidal impact with the lunar surface. As these ejecta escape the Earth-Moon environment, they face a dynamical barrier for entry into Earth's co-orbital space. However, a small fraction of launch conditions yields outcomes that are compatible with Kamo'oalewa's orbit. The most favored conditions are launch velocities slightly above the escape velocity from the trailing lunar hemisphere., Competing Interests: Competing interestsThe authors declare no competing interests., (© The Author(s) 2023.)

Close-up images from NASA's New Horizons probe show that space rock has two distinct lobes. Close-up images from NASA's New Horizons probe show that space rock has two distinct lobes. [ABSTRACT FROM AUTHOR]

Meteorite magnetizations can provide rare insight into early Solar System evolution. Such data take on new importance with recognition of the isotopic dichotomy between non-carbonaceous and carbonaceous meteorites, representing distinct inner and outer disk reservoirs, and the likelihood that parent body asteroids were once separated by Jupiter and subsequently mixed. The arrival time of these parent bodies into the main asteroid belt, however, has heretofore been unknown. Herein, we show that weak CV (Vigarano type) and CM (Mighei type) carbonaceous chondrite remanent magnetizations indicate acquisition by the solar wind 4.2 to 4.8 million years after Ca-Al-rich inclusion (CAI) formation at heliocentric distances of ~2-4 AU. These data thus indicate that the CV and CM parent asteroids had arrived near, or within, the orbital range of the present-day asteroid belt from the outer disk isotopic reservoir within the first 5 million years of Solar System history., Competing Interests: Competing interestsThe authors declare no competing interests., (© The Author(s) 2020.)