Category Astronomy/Space

A new map of the thickness of Mars’ crust shows less variation between thicker regions (red) and thinner regions (blue), compared to earlier mapping. This view is centered on Valles Marineris, with the Tharsis Montes near the terminator to its west. The map is based on modeling of the Red Planet’s gravity field by scientists at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. The team found that globally Mars’ crust is less dense, on average, than previously thought, which implies smaller variations in crustal thickness. Credit: NASA/Goddard/UMBC/MIT/E. Mazarico

NASA scientists have found evidence that Mars’ crust is not as dense as previously thought, a clue that could help researchers better understand the Red Planet’s interior structure and evolution...

AR Scorpii

Astronomers studying the unique binary star system AR Scorpii have discovered the brightness of the system has changed over the past decade. The new evidence lends support to an existing theory of how the unusual star emits energy. AR Scorpii consists of a rapidly spinning, magnetized white dwarf star that mysteriously interacts with its companion star. The system was recently found to more than double in brightness on timescales of minutes and hours, but research recently published in The Astrophysical Journal Letters found variability on a timescale of decades.

Researchers at the University of Notre Dame analyzed data on the unique system from the Kepler Space Telescope’s K2 mission taken in 2014 before the star was known to be unusual...

Galaxies from the SAMI survey, imaged with Japan’s Subaru telescope. Credit: D. Taranu (University of Western Australia), C. Foster (University of Sydney), NAOJ (the National Astronomical Observatory of Japan)

For the first time astronomers have measured how a galaxy’s spin affects its shape. It sounds simple, but measuring a galaxy’s true 3D shape is a tricky problem that astronomers first tried to solve 90 years ago. “This is the first time we’ve been able to reliably measure how a galaxy’s shape depends on any of its other properties – in this case, its rotation speed,” said research team leader Dr Caroline Foster of the University of Sydney, who completed this research while working at the Australian Astronomical Observatory.

Galaxies can be shaped like a pancake, a sea urchin or a foo...