Moon's farside hints at violent volcanic explosions

The farside of the moon may have had some extremely explosive volcanic eruptions hundreds of millions of years ago. 

In 2011, scientists identified rare, silica volcanoes in a highly reflective plain called the Compton-Belkovich region. A reanalysis of thorium in that region shows that the element spreads 300 kilometers farther east than originally thought, suggesting that the silica volcanoes exploded violently, shooting rock and gas across that area of the moon. The findings, reported in a paper submitted to the Journal of Geophysical Research and posted September 3 on arXiv.org, appear to be the first evidence of vigorous, explosive silica volcanism on the moon.