Open AccessCold jets in the Martian polar caps
Author(s) -
Kieffer Hugh H.
Publication year - 2007
Publication title -
journal of geophysical research: planets
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2006je002816
Subject(s) - martian , geology , mars exploration program , polar , sunrise , astrobiology , atmospheric sciences , atmosphere (unit) , atmosphere of mars , outgassing , albedo (alchemy) , snow , geomorphology , meteorology , physics , astronomy , art , performance art , art history
Mars seasonal polar caps display dark ice, local darker spots, aligned elongate patches, and radially dendritic forms that reverse albedo contrast. The unexpected variety and sequence of these features are explained on the basis of processes involving CO 2 , dust, sand, and H 2 O. These processes are largely related to the atmosphere being near its saturation temperature, and they have few terrestrial analogies. In the simplest case the ∼1 m thick seasonal cap, initially dusty, cleans itself and becomes translucent after sunrise and is impermeable over extensive regions except for local vents. The slab ice sublimates at the base and is levitated on high‐pressure gas, causing humidity exchange with deeper layers; subslab gas converging toward the vents erodes channels in the soil and ejects this material in high‐velocity jets. Recent spectral observations indicate great variety in the details.