Category Astronomy/Space

The actual mechanism causing asteroids to disrupt is still unknown but some obvious scenarios such as tidal forces caused by the Sun and direct sublimation of silicates have been ruled out. One of the remaining scenarios is that volatiles inside the asteroid sublimate at moderate temperatures and create enough pressure to blow up the body. A similar process on a smaller scale called spalling can also break up surface rocks. Credit: Lauri Voutilainen

This is an artist’s impression of the clash of powerful stellar winds. Credit: NASA/C. Reed

10 arcmin x 10 arcmin field showing luminosity (top) and temperature (bottom) maps of Abell 3888 before (left) and after (right) point source removal. The color scale in the luminosity map is set so that white corresponds to the maximum cluster flux. The point source is 100 times brighter than this level. The scale in the temperature map ranges from 2 to 10 keV. Credit: Andersson, K. et al., 2009

Perspective views of (top) the floor of a basin where Rodriguez and others propose in this investigation that shallow lakes could have formed within the last few tens of millions of years, and (below) the floor of a proposed Martian analog high mountain lake in the Tibetan plateau, where Rodriguez will conduct a field investigation this coming summer. The arrows in both panels identify similar ridges that surround the basin’s floor. In the Tibetan lake case, the ridges are thought to form as sediments are pushed outwards by the freezing waters. These types of ridges might be diagnostic shoreline feature of lakes that formed under extremely cold and dry Martian conditions...