Category Astronomy/Space

Different types of plasma waves triggered by various mechanisms, occupy different regions of space around Earth.
Credits: NASA’s Goddard Space Flight Center/Mary Pat Hrybyk-Keith

NASA’s Van Allen Probes have observed a new population of space sound waves, called plasmaspheric hiss, which are important in removing high-energy particles from around Earth that can damage satellites. Disturbances in space, can cause waves which occur as fluctuating electric and magnetic fields plow through clumps of ions and electrons that compose the plasma, pushing some to accelerated speeds. This interaction controls the balance of highly energetic particles injected and lost from in the near-Earth environment.

One type of plasma wave fundamental to shaping our near-Earth environment are whistler-mode waves...

Scientists at UConn and North Carolina State University have found that reducing oxygen content in some nanocrystalline materials may improve their grain size stability at elevated temperatures. This graphic shows the pattern of stability for Iron-Chromium-Hafnium nanograins with oxygen (represented by red triangles) and without oxygen (represented by black squares) as temperature increases relative to thermodynamic prediction.
Credit: Image courtesy of Peiman Shahbeigi-Roodposhti

Researchers at the University of Connecticut have found that reducing oxygen in some nanocrystalline materials may improve their strength and durability at elevated temperatures, a promising enhancement that could lead to better biosensors, faster jet engines, and greater capacity semiconductors...

This image shows the model of the tidally shredded Sagittarius dwarf galaxy wrapping around a 3-D representation of the Milky Way disk (flattened blue spiral). The yellow dot represents the position of the Sun. Credit: David R. Law/UCLA.

An international team has performed detailed measurements of the chemical composition of 158 red giant stars in the nearby Sagittarius dwarf galaxy. The study is so far the largest and most chemically extensive high-resolution survey of this galaxy. Discovered in 1994, Sagittarius is a nearby, massive, elliptical loop-shaped satellite galaxy of the Milky Way. The dwarf is currently merging with our galaxy, resulting in massive tidal tails that can be found in the Galactic halo...

These images show temperature maps as simulated by MAGHNUM as a result of mud convection, in a medium sized asteroid (above) and a large asteroid (below). Temperatures are shown in degrees Celcius. Credit: Planetary Science Institute

Scientists have long held the belief that planets – including Earth – were built from rocky asteroids, but new research challenges that view. The research suggests that many of the original planetary building blocks in our solar system may actually have started life, not as rocky asteroids, but as gigantic balls of warm mud. Phil Bland, Curtin University planetary scientist, undertook the research to try and get a better insight into how smaller planets, the precursors to the larger terrestrial planets we know today, may have come about.

Planetary Science...