Planetary science: Titan's sea is super salty
Nature 511, 7509 (2014). doi:10.1038/511266b
Saturn's largest moon, Titan, has a buried ocean that is saltier than many seas on Earth.Titan, with its thick atmosphere and bodies of surface liquid, is of great interest to scientists looking for life beyond Earth. A team led by Giuseppe Mitri, of the
A deep crust–mantle boundary in the asteroid 4 Vesta
Nature 511, 7509 (2014). doi:10.1038/nature13499
Authors: Harold Clenet, Martin Jutzi, Jean-Alix Barrat, Erik I. Asphaug, Willy Benz & Philippe Gillet
The asteroid 4 Vesta was recently found to have two large impact craters near its south pole, exposing subsurface material. Modelling suggested that surface material in the northern hemisphere of Vesta came from a depth of about 20 kilometres, whereas the exposed southern material comes from a depth of 60 to 100 kilometres. Large amounts of olivine from the mantle were not seen, suggesting that the outer 100 kilometres or so is mainly igneous crust. Here we analyse the data on Vesta and conclude that the crust–mantle boundary (or Moho) is deeper than 80 kilometres.
It seems like our compulsive universe can be downright capricious when it comes to making oddball-looking things in the cosmos. The latest surprise to Hubble astronomers is a 100,000-light-year-long structure that looks like a string of pearls twisted into a corkscrew shape. This Slinky-like structure forms a bridge between two giant elliptical galaxies that are colliding. The "pearls" on the Slinky are superclusters of blazing, blue-white, newly born stars. The whole assembly, which looks like a tug-of-war, must result from the gravitational tidal forces present in the collision.