Illumination Analysis of Louth Crater and Its Relation with Ice Deposits

MANTEGAZZA, MARA; SPAGNUOLO, MAURO

Congreso; Congreso; 52nd Lunar and Planetary Science Conference; 2021; 2021

In the Martian north polar regions there are over 10 ice deposits contained in the interior of different craters. One of these deposits is found in Louth Crater. Louth is a 36 km diameter crater 1.5 km depth. It is located at ~70.2°N 102.3°W and represents one of the most southern water ice deposits. Its interior contains a ~10 km diameter ice mound placed near the center of the crater floor, slightly shifted to the north. Previous works describe the morphology, composition and models the mass balance of the ice mounds. However, the origin of this ice deposits in still poorly understood mainly because of the most-equatorward position. In previous works it was proposed that inner-crater ice mounds developed under unique atmospherics conditions in what is known as ?cold traps?. An alternative hypothesis argues that these equatorward ice deposits might be related with a more extensive ice cap. Most geological evidence point to a model of atmospheric deposition of water vapor in the center of the crater. Moreover, the offset position of the ice mound was attributed to depositional process, aeolian activity and sublimation. In this work we explore the relation of illumination and solar energy with the position of the ice mound inside Louth crater. We explore three hypotheses of formation: i) the ice mound represents a residual North Polar Cap deposits ii) it was formed in the center of Louth crater and shifted to the north or iii) it was formed at its present offset position from the center. We analyzed the shadows distribution in Louth Crater and the solar energy in order to evaluate if the north ice mound region represents a low illumination region that defines ice precipitation.