... Star Clouds Toward the Southern Crown . ... The dust appears bluer when seen near bright stars because it preferentially reflects blue light. Rectangular Ridges on Mars . ... What could cause rectangular ridges on Mars? ... D rad Bacteria: Candidate Astronauts . ... The graceful spiral structure seen in this computer visualization does not portray winding spiral arms in a distant galaxy of stars. Instead, the graphic shows spiral.. ... Have you ever seen the band of our Milky Way Galaxy? ...