Changes

Mars cannot have liquid water on its surface. The thin atmosphere does not permit this, even during high summer on Mars. Yet the [[Mars Global Surveyor]] mission in June 2000 took photographs of gully-like formations on several precipices and crater walls on Mars. These formations tend to occur between 30° and 70° north and south latitude. Mission analysts further suggest that these formations are relatively fresh and estimate that liquid water might be found less than 500 meters beneath the surface.<ref name=msss>"[http://www.msss.com/mars_images/moc/june2000/ MOC Images Suggest Recent Sources of Liquid Water on Mars]." Malin Space Science Systems, June 22, 2000. Accessed May 27, 2008.</ref>

Mars cannot have liquid water on its surface. The thin atmosphere does not permit this, even during high summer on Mars. Yet the [[Mars Global Surveyor]] mission in June 2000 took photographs of gully-like formations on several precipices and crater walls on Mars. These formations tend to occur between 30° and 70° north and south latitude. Mission analysts further suggest that these formations are relatively fresh and estimate that liquid water might be found less than 500 meters beneath the surface.<ref name=msss>"[http://www.msss.com/mars_images/moc/june2000/ MOC Images Suggest Recent Sources of Liquid Water on Mars]." Malin Space Science Systems, June 22, 2000. Accessed May 27, 2008.</ref>

More recently, NASA's latest mission, the [[Phoenix lander]], has discovered what appears to be water ice very near the surface near Mars' north pole. Furthermore, analysis of a cubic meter of soil at this site reveals that the soil is far more [[alkali]]ne than expected, and has tolerable levels of salt and low levels of [[calcium]]. Investigators have even suggested that the soil might support the growth of an Earth vegetable, like [[asparagus]],<ref name=courier>"[http://www.news.com.au/couriermail/story/0,23739,23932393-5013016,00.html Scientists find soil on Mars good enough to grow asparagus]." ''The Courier Mail'', June 28, 2008. Accessed June 30, 2008.</ref> if not for the fact that the atmosphere is too thin for water to be a liquid.

More recently, NASA's latest mission, the [[Phoenix lander]], has discovered what appears to be water ice very near the surface near Mars' north pole. Furthermore, analysis of a cubic meter of soil at this site reveals that the soil is far more [[alkali]]ne than expected, and has tolerable levels of salt and low levels of [[calcium]]. Investigators have even suggested that the soil might support the growth of an Earth vegetable, like [[asparagus]].<ref name=courier>"[http://www.news.com.au/couriermail/story/0,23739,23932393-5013016,00.html Scientists find soil on Mars good enough to grow asparagus]." ''The Courier Mail'', June 28, 2008. Accessed June 30, 2008.</ref>

== Life on Mars ==

== Life on Mars ==