Journal Archives


Call for Papers

A special polar issue of Planetary and Space Science is out. The table of context for this issue is found at Planetary & Space Science, Volume 56 Issue 2.


Cold jets in the Martian polar caps

Hugh H. Kieffer
Celestial Reasonings, Genoa, Nevada, USA


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 CO2, dust, sand, and H2O. 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.

This paper can be download at:


August 2006, Letters to Nature

“No signature of clear CO2 ice from the 'cryptic' regions in Mars' south seasonal polar cap”
While these findings appear consistent with the Kieffer et. al., the OEMGA team does suggest an alternate and competing model. Read More


August 2006, Letters to Nature

Scientists have now found a better explanation for the dark spots and fans found on the south polar region of Mars. These spots, which can cover tens of square kilometers, are visible in the cryptic region. Originally, it was suggested that the spots were soil, exposed after early defrosting of the polar ice. However, an intensive new study with the Mars Odyssey Thermal Emission Imaging System (THEMIS) shows that the temperatures of the spots are inconsistent with expected temperatures of soil. Instead, the dark spots are within a few degrees of solid CO2 (~ -130°C). Soil, even when bordered by CO2, is greater than ~ -50°C. This suggests that the dark spots exists either on top, underneath, or inside of a layer of CO2. The previous suggestion that the spots are defrosted, CO2 ice free regions, no longer seems plausible. Read More


May 12, 2005

"Scientists think they have an answer to the long-standing mystery of why the permanent icecap on Mars' South Pole is offset from the pole itself. Simply put, it's colder and stormier in that hemisphere.

But that is only part of the equation, they say, and new understanding about Mars' climate and its polar regions may suggest clues to finding water in the planet's equatorial zone - where it would be easier to land a spacecraft - and opening the door to future exploration." Read more at the Corvallis Gazette-Times or read the journal article at LPI: Read the Article [PDF]


April 2005, Icarus Polar Issue

The April 2005 issue of Icarus is focused on Martian polar studies. In it are many different and interesting articles on ice and how it relates to Mars. See the Journal