We confirm the planetary nature of TOI-5344 b as a transiting giant exoplanet around an M0-dwarf star. TOI-5344 b was discovered with the Transiting Exoplanet Survey Satellite photometry and confirmed with ground-based photometry (the Red Buttes Observatory 0.6 m telescope), radial velocity (the Habitable-zone Planet Finder), and speckle imaging (the NN-Explore Exoplanet Stellar Speckle Imager). TOI-5344 b is a Saturn-like giant planet (rho = 0.80 -0.15+0.17 g cm-3) with a planetary radius of 9.7 +/- 0.5 R circle plus (0.87 +/- 0.04 R Jup) and a planetary mass of 135-18+17M circle plus (0.42 -0.06+0.05MJup ). It has an orbital period of 3.792622-0.000010+0.000010 days and an orbital eccentricity of 0.06-0.04+0.07 . We measure a high metallicity for TOI-5344 of [Fe/H] = 0.48 +/- 0.12, where the high metallicity is consistent with expectations from formation through core accretion. We compare the metallicity of the M-dwarf hosts of giant exoplanets to that of M-dwarf hosts of nongiants (less than or similar to 8 R circle plus). While the two populations appear to show different metallicity distributions, quantitative tests are prohibited by various sample caveats.

We report the measurement of the sky-projected obliquity angle lambda of the warm Jovian exoplanet TOI-1670 c via the Rossiter-McLaughlin effect. We observed the transit window during UT 2023 April 20 for 7 continuous hours with NEID on the 3.5 m WIYN Telescope at Kitt Peak National Observatory. TOI-1670 hosts a sub-Neptune (P similar to 11 days; planet b) interior to the warm Jovian (P similar to 40 days; planet c), which presents an opportunity to investigate the dynamics of a warm Jupiter with an inner companion. Additionally, TOI-1670 c is now among the longest-period planets to date to have its sky-projected obliquity angle measured. We find planet c is well aligned to the host star, with lambda = - 0.degrees 3 +/- 2.degrees 2. TOI-1670 c joins a growing census of aligned warm Jupiters around single stars and aligned planets in multiplanet systems.

Boron has been detected on Mars in calcium-sulfate veins found within clay mineral rich rocks on Mars by the Mars Science Laboratory (MSL) Curiosity rover using Laser Induced Breakdown Spectroscopy (LIBS) analysis. Borates play a vital role in stabilizing ribose on Earth and has been suggested as a key requirement for life. Borate ions readily adsorb to phyllosilicate clay minerals. The discovery of boron on Mars in proximity to phyllosilicatebearing bedrock may have strong implications for potential past prebiotic conditions on Mars. In this study we generated a suite of clay minerals with adsorbed borate, including both typical terrestrial clay minerals (montmorillonite) and Mars-analog clay minerals (nontronite, saponite, griffithite), to understand controls on borate adsorption and to analyze with LIBS to compare with MSL data. Clay minerals were subjected to mineralogical and chemical analysis before and after adsorption. Adsorption analysis revealed that the Mars analog clay minerals adsorbed less boron than terrestrial counterparts, but within comparable amounts to those detected on Mars and in meteorites. Post-adsorption analysis by X-ray diffraction (XRD) revealed slight changes in the interlayer spacing of many of the clay minerals. Based on the adsorption analysis of the Mars-analog clay minerals, phyllosilicate-bearing bedrock in Gale crater may contain up to 90-110 ppm B. A series of borateenriched samples were created for analysis of LIBS spectra from ChemCam on the Curiosity rover and SuperCam on the Perseverance Rover. The results of this study may provide insight into martian groundwater geochemistry processes and the mobility of a key molecule connected with life.

We present and analyze a three-dimensional (3D) volume of nanoscale helium bubbles in a tritium-exposed palladium alloy that we have reconstructed by transmission electron tomography. Helium nanobubbles commonly form within metals during exposure to radiation and radioactive substances. The radioactive decay of tritium stored in metal tritides often results in a high density of these nanoscale helium bubbles. A persistent question about the mechanisms of bubble nucleation and growth has been the role of lattice defects and impurities. To address this matter, we have determined the 3D positions of helium nanobubbles in a palladium-nickel alloy exposed to tritium for 3.8 years. We introduce methods to determine the 3D shapes, volumes, and spatial positions of helium bubbles as small as 1 nm within solids. We find that the size and spacing of observed nanobubbles are not correlated. Our results suggest that previous models, which hypothesize initial, rapid homogeneous nucleation of nanobubbles followed by diffusion-limited growth as helium atoms join the nearest bubble, are inadequate. We propose that the lack of size and spacing correlation is due to traps of atomic helium in the metal lattice that allow bubbles to nucleate even at low average helium concentration. This work will facilitate the development of high-fidelity models of helium nanobubble formation in radiation-exposed metals.

A direct comparison between electron transparent transmission electron microscope (TEM) samples prepared with gallium (Ga) and xenon (Xe) focused ion beams (FIBs) is performed to determine if equivalent quality samples can be prepared with both ion species. We prepared samples using Ga FIB and Xe plasma focused ion beam (PFIB) while altering a variety of different deposition and milling parameters. The samples' final thicknesses were evaluated using STEM-EELS t/lambda data. Using the Ga FIB sample as a standard, we compared the Xe PFIB samples to the standard and to each other. We show that although the Xe PFIB sample preparation technique is quite different from the Ga FIB technique, it is possible to produce high-quality, large area TEM samples with Xe PFIB. We also describe best practices for a Xe PFIB TEM sample preparation workflow to enable consistent success for any thoughtful FIB operator. For Xe PFIB, we show that a decision must be made between the ultimate sample thickness and the size of the electron transparent region.