An evaporite sequence from ancient brine recorded in Bennu samples - Nature Samples from the asteroid (101955) Bennu, returned by the OSIRIS-REx mission, include sodium-bearing phosphates and sodium-rich carbonates, sulfates, chlorides and fluorides formed during evaporation ...

This paper was published in @nature.com by McCoy et al. on January 29th, 2025. (2/2)

Link: www.nature.com/articles/s41...

This figure shows 3 panels. On the left, a clast of the sample includes sodium sulfate grains. The middle panel shows an ion map with halite (NaCl) and sylvite (KCl) identified in a particle. On the right, sodium fluoride grains are identified with phyllosilicates.

This week’s figure shows a close-up view of samples returned by the OSIRIS-REx spacecraft from asteroid Bennu. The authors identify salt minerals in the sample, which could also occur on many astrobiologically relevant bodies in the solar system, including Ceres and Enceladus. (1/2)

Dichotomy retreat and aqueous alteration on Noachian Mars recorded in highland remnants - Nature Geoscience The Martian dichotomy boundary receded hundreds of kilometres in the Mawrth Vallis region and left behind mounds that record changing aqueous conditions during the Noachian (4.1–3.7 Ga), according to ...

This paper was published by McNeil et al. on Jan. 20th in Nature Geoscience. Link: www.nature.com/articles/s41...

This plot explores a mound in Mawrth Vallis, an ancient valley on Mars. In the top left is a map showing the location of the mound within the Chryse Planitia region. In the lower left is a 3D view of the mound, rendered using a digital terrain model. CRISM infrared spectra are shown on the right side to compare the mineralogy of various sections of the mound with different elevations and surface expressions. USGS reference spectra for nontronite, vermiculate, and saponite (three clay minerals) are displayed in the bottom right.

This week’s figure shows a km-scale mound in Mawrth Vallis, Mars. Variability in infrared spectral signatures with elevation are used to build a stratigraphic column, which suggests there was a region-wide succession of igneous material followed by extensive aqueous alteration.