@MISC{Crater_moundcon, author = {Horace W. Crater and Stanley V. Mcdaniel}, title = {Mound Con gurations on the Martian Cydonia Plain}, year = {} }

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Abstract

Abstract — We show that a group of mound-like formations in the Cydonia area of Mars of relatively small and nearly uniform size have relative posi-tions that repeatedly display symmetries in the apparent form of related right and isosceles triangles. We also show that these pairs cluster sharply in densi-ty about a certain value of the defining angle of those related triangles and that on average the vertices of the triangles lie significantly closer to the mea-sured centers of the mounds than those for fictitious mounds from a comput-er simulation. Our computer simulation of the surrounding features and the mound formations themselves demonstrates that the numerous examples of these symmetries, the resultant clustering about certain proportions, and the relative precision of the vertices to the mound centers are not compatible with random geological forces. We have thus uncovered an anomaly of number, geometry, and precision. In order to give a quantitative measure of this anom-alous distribution of mounds we determine the likelihood that we will make an error by rejecting the null hypothesis. This level of significance we find for our test is p~15.5 ́ 10- 6. That is, in a million trials, the repetition of the fre-quency of appearance of these triangles, greater than or equal to the observed (19) in the actual data, and with the observed or greater precision, is about 15 + 2.5. In this computer simulation the average number of appearances is about 6, with a standard deviation of about 2. In 95 % of the computer simula-tions, the distance of the vertices of the triangles was, on average, further from the (fictitious) mound centers than for the case of the actual mounds.