the Opportunity Rover on the rim of Endeavour crater. These are found near joints and fractures that allowed deep fluid circulation which caused chemical and thermal alteration of the rocks. So, the area around martian craters may contain a variety of minerals that were produced as an indirect result of an impact. Heat from impacts results from several processes. Immediately after an impact, there is a rebound off the floor which causes hotter rocks to be uplifted to the surface. However, most of the heat comes from the kinetic energy that is produced during the impact. This enormous heat creates several useful products that may start forming early and then continue for some time. These are called "epigenetic deposits." Circulation of hot mineral-rich fluids in the fractures from the impact cause hydrothermalism. Important examples are the Cu-Ni sulfides at the Sudbury Igneous Complex in Canada. For a number of years, these ores from the Sudbury area had a value of $2 billion each year. The Sudbury formation has provided us with ores of zinc, copper, gold, and lead. Strong evidence for hydrothermalism was reported by a team of researchers studying Auki Crater. This crater contains ridges that may have been produced after fractures formed with an impact. Using instruments on the Mars Reconnaissance Orbiter they found the minerals Smectite, Silica, Zeolite, Serpentine, Carbonate, and Chlorite that are common in impact-induced hydrothermal systems on Earth. There is other evidence of post-impact hydrothermal systems on Mars from other scientists who studied other Martian craters. The surface of Mars contains abundant evidence of a wetter climate in the past along with ice frozen in the ground today; therefore it is quite possible that hydrothermal systems could be set up from impact heat. NASA's Mars Odyssey actually measured the distribution of ice from orbit with a gamma ray spectrometer. So, in the past, much water could have been available to circulate in cracks and deposit new minerals. This process, called hydrothermal alteration has been found in a meteorite from Mars. Research, published in February 2011, detailed the discovery of clay minerals, serpentine, and carbonate in the veins of a Nakhlite martian meteorite. The Phoenix lander, whose rocket engine blast actually exposed a layer of ice, watched ice melt (the ice disappeared by sublimation). Because 30% of the roughly 180 impact craters on Earth contain minerals or oil and gas, it seems that the cratering