Station Science Top News: Jan. 17, 2025

NASA · January 21

Insights into metal alloy solidification

Researchers report details of phase and structure in the solidification of metal alloys on the International Space Station, including formation of microstructures. Because these microstructures determine a material’s mechanical properties, this work could support improvements in techniques for producing coatings and additive manufacturing or 3D printing processes.

METCOMP, an ESA (European Space Agency) investigation, studied solidification in microgravity using transparent organic mixtures as stand-ins for metal alloys. Conducting the research in microgravity removed the influence of convection and other effects of gravity. Results help scientists better understand and validate models of solidification mechanisms, enabling better forecasting of microstructures and improving manufacturing processes.

The image shows a monochromatic scene with a gradient of brightness transitioning from dark to light. A textured surface appears in the central region.

Image from the METCOMP investigation of how a metal alloy could look like as it solidifies.

E-USOC

Measuring the height of upper-atmospheric electrical discharges

Researchers determined the height of a blue discharge from a thundercloud using ground-based electric field measurements and space-based optical measurements from Atmosphere-Space Interactions Monitor (ASIM). This finding helps scientists better understand how these high-altitude lightning-related events affect atmospheric chemistry and could help improve atmospheric models and climate and weather predictions.

ESA’s ASIM is an Earth observation facility that studies severe thunderstorms and upper-atmospheric lighting events and their role in the Earth’s atmosphere and climate. Upper-atmospheric lightning, also known as transient luminous events, occurs well above the altitudes of normal lightning and storm clouds. The data collected by ASIM could support research on the statistical properties of many upper atmosphere lightning events, such as comparison of peak intensities of blue and red pulses with reports from lightning detection networks.

An artistic representation of Earth from space. Bright clouds cover most of the planet, while a blue jet of light extends from the atmosphere into space.

An artist’s impression of a blue jet as observed from the International Space Station.

Mount Visual/University of Bergen/DTU

Modeling a complex neutron star

Scientists report that they can use modeling of neutron star PSRJ1231−1411’s X-ray pulses to infer its mass and radius and narrow the possible behaviors of the dense matter at its core. This finding provides a better understanding of the composition and structure of these celestial objects, improving models that help answer questions about conditions in the universe.

The Neutron star Interior Composition Explorer provides high-precision measurements of pulses of X-ray radiation from neutron stars. This particular neutron star presented challenges in finding a fit between models and data, possibly due to fundamental issues with its pulse profile. The authors recommend a program of simulations using synthetic data to determine whether there are fundamental issues with this type of pulse profile that could prevent efforts to obtain tighter and more robust constraints.