Sunlight Can Crack Rocks on Asteroids

Here on Earth the surfaces of pretty much all but the most freshly-exposed (geologically-speaking, of course) rock surfaces exhibit the effects of atmospheric weathering—from rain, snow, and ice to wind, dust-blown sand, flowing water, and extreme heat. And underlying all of that are the relentless forces of tectonic activity. But on dry, airless, and tectonically…

Gully Gee…

One of thousands of new images released on September 2 from the University of Arizona’s HiRISE project, this amazingly detailed image shows the dramatic effects of erosion on the steep sides of Hale Crater on Mars. Whether or not these channels were caused by liquid water or a dry process is still under investigation. It’s…