.THE function of Bayesian contradiction to a series of lithologic guidelines in an evaluation of seismic data barely seems to be the stuff of headings. However when the seismic information you are actually evaluating come from Mars, as well as when your thinking advises that the greatest description for them is actually liquid water in the pores between stones, you have an account. There is little people crave more, when it involves earthly science, than water on Mars. Why performs the possibility produce such exhilaration-- and what does this new investigation add to the account?