In a challenge to current astrophysical models of the universe, researchers have found that current estimates of the interiors of so-called ice giant planets within and without the solar system overstate water's compressibility by as much as 30 percent, forcing revisions in estimates of other elements.

More than 400 years after Galileo's discovery of Io, the innermost of Jupiter's largest moons, a team of scientists has produced the first complete global geologic map of the Jovian satellite.

Space scientists report they have quantified levels of radiation on the moon's surface from galactic cosmic ray (GCR) bombardment that over time causes chemical changes in water ice and can create complex carbon chains similar to those that help form the foundations of biological structures. In addition, the radiation process causes the lunar soil, or regolith, to darken over time, which is important in understanding the geologic history of the moon.

Computer simulations have revealed a plausible explanation for a phenomenon that has puzzled astronomers: Rather than occupying orbits at regular distances from a star, giant gas planets similar to Jupiter and Saturn appear to prefer to occupy certain regions in mature solar systems while staying clear of others.