Details

Autor(en) / Beteiligte

• Martínez, G.M.
• Fischer, E.
• Rennó, N.O.
• Sebastián, E.
• Kemppinen, O.
• Bridges, N.
• Borlina, C.S.
• Meslin, P.-Y.
• Genzer, M.
• Harri, A.-H.
• Vicente-Retortillo, A.
• Ramos, M.
• de la Torre Juárez,  M.
• Gómez, F.
• Gómez-Elvira, J.

Titel

Likely frost events at Gale crater: Analysis from MSL/REMS measurements

Ist Teil von

• Icarus (New York, N.Y. 1962), 2016-12, Vol.280, p.93-102

Ort / Verlag

Elsevier Inc

Erscheinungsjahr

2016

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• •Surface frost events could have occurred at Gale between sols 400 and 710.•Most likely frost events occurred at Dingo Gap megaripple.•The thickness of the frost layer calculated at Dingo Gap shows values of tenths of μm. We provide indirect evidence for the formation of frost at the surface of Gale crater by analyzing the highest confidence data from simultaneous measurements of relative humidity and ground temperature during the first 1000sols of the Mars Science Laboratory (MSL) mission. We find that except for sol 44, frost events could have occurred only between sols 400 and 710, corresponding to the most humid and coldest time of the year (from early fall to late winter). In particular, measurements at Dingo Gap during sols 529–535, at an unnamed place during sols 554–560, at Kimberley during sols 609–617 and at an unnamed place during sols 673–676 showed the largest likelihood of the occurrence of frost events. At these four locations, the terrain is composed of fine-grained and loosely packed material with thermal inertia values of ∼200 SI units, much lower than the 365±50 SI units value found at the landing ellipse. This is important because terrains with exceptionally low thermal inertia favor the formation of frost by lowering minimum daily ground temperatures. An order-of-magnitude calculation to determine the thickness of the frost layer at these four locations results in values of tenths of µm, while the precipitable water content is a few pr-µm. Therefore, surface frost events can have important implications for the local water cycle at Gale crater. In addition, frost is the most likely type of water that can be temporarily found in bulk amounts on the surface of Mars at low latitudes and therefore can cause weathering, influencing the geology of Gale crater.