- Jan 27, 2020
- 588
- 130
- 5,080
In addition to the marvelous article appearing on the Live Science's front page, 'China's Mars rover may be dead in the dust, new NASA images reveal' by Stephanie Pappas, I thought I would offer the original article which also offers information on the subsurface geological elements and buried craters. The Chinese rover, Tianwen-1, employed the Mars Rover Penetrating Radar (RoPeR) to unveil the detailed structure of the regolith layer and assess its loss tangent.
Martian soil as revealed by ground-penetrating radar at the Tianwen-1 landing site
by Ruonan Chen; Ling Zhang; Yi Xu; Renrui Liu; Roberto Bugiolacchi; Xiaoping Zhang; Lu Chen; Zhaofa Zeng;
and Cai Liu
Geology (2023) 51 (3): 315–319.
Much of the Martian surface is covered by a weathering layer (regolith or soil) produced by long-term surface processes such as impact gardening, eolian erosion, water weathering, and glacial modifications. China’s first Martian mission, Tianwen-1, employed the Mars Rover Penetrating Radar (RoPeR) to unveil the detailed structure of the regolith layer and assess its loss tangent. The RoPeR radargram revealed the local regolith layer to be highly heterogeneous and geologically complex and characterized by structures that resemble partial or complete crater walls and near-surface impact lenses at a very shallow depth. However, comparable radar data from the Lunar far side are rather uniform, despite the two surfaces being geologically contemporary. The close-to-surface crater presented in this study shows no detectable surface expression, which suggests an accelerated occultation rate for small craters on the surface of Mars as compared to the rate on the Moon. This is probably due to the relentless eolian processes on the Martian surface that led to the burial of the crater and thus shielded it from further erosion. The high loss tangent indicates that the regolith at the Tianwen-1 landing site is not dominated by water ice.
The Zhurong rover, released by the lander, traversed about 1.2 km southward in the first six
months, navigating around dunes and driving on small craters or small rocks where possible,
as illustrated, on terrains with a gradually decreasing surface elevation.
Geomorphologically and topographically, the surface terrain during this traverse remains
flat and smooth with an average slope of 3±0.2° in most areas, facilitating long -distance traversal. Tens of impact craters with a diameter of 2-10 m with varying degrees of degradation can be seen in orbital images along this travers. Some show relatively high albedo and protuberant rims, and others have little relief, which makes it difficult to assess whether they are either primary or secondary impacts. Many rocks of various sizes (smaller than 2 m) are scattered on and around the exploration path. Over two million rocks with diameters ranging from 1.4 to 8m were also observed from the high-resolution imaging camera (HiRIC; 0.7 m/pixel) mosaics within the landing region. Some of the rocks seen by NaTeCam are clearly fluted, suggesting aeolian abrasion. Aeolian bed forms are also commonly found along the exploration path.
For more information on this interesting paper, see: https://pubs.geoscienceworld.org/gsa/geology/article-abstract/51/3/315/620359/Martian-soil-as-revealed-by-ground-penetrating
The Chinese rover, Tianwen-1, before it became dust bound, offered some tantalising clues about the Martian sub-surface detail and the possible reasons for their being covered by soil. Often times even the failures in exploration offer us critical clues concerning the explorations and what can be expected from future examinations. The increasing use of sub-surface radar along with its continuing miniaturisation will aid future Mars explorations - much as ground penetrating everywhere on Earth assists in archaeology, particularly in the exploration of Meso-American sites.
Also, recall that the term 'aeolian' refers to the wind and that aeolian abrasion means wind weathering with wind blown particulate matter causing the scouring of surface.
Hartmann352
Martian soil as revealed by ground-penetrating radar at the Tianwen-1 landing site
by Ruonan Chen; Ling Zhang; Yi Xu; Renrui Liu; Roberto Bugiolacchi; Xiaoping Zhang; Lu Chen; Zhaofa Zeng;
and Cai Liu
Geology (2023) 51 (3): 315–319.
Much of the Martian surface is covered by a weathering layer (regolith or soil) produced by long-term surface processes such as impact gardening, eolian erosion, water weathering, and glacial modifications. China’s first Martian mission, Tianwen-1, employed the Mars Rover Penetrating Radar (RoPeR) to unveil the detailed structure of the regolith layer and assess its loss tangent. The RoPeR radargram revealed the local regolith layer to be highly heterogeneous and geologically complex and characterized by structures that resemble partial or complete crater walls and near-surface impact lenses at a very shallow depth. However, comparable radar data from the Lunar far side are rather uniform, despite the two surfaces being geologically contemporary. The close-to-surface crater presented in this study shows no detectable surface expression, which suggests an accelerated occultation rate for small craters on the surface of Mars as compared to the rate on the Moon. This is probably due to the relentless eolian processes on the Martian surface that led to the burial of the crater and thus shielded it from further erosion. The high loss tangent indicates that the regolith at the Tianwen-1 landing site is not dominated by water ice.
The Zhurong rover, released by the lander, traversed about 1.2 km southward in the first six
months, navigating around dunes and driving on small craters or small rocks where possible,
as illustrated, on terrains with a gradually decreasing surface elevation.
Geomorphologically and topographically, the surface terrain during this traverse remains
flat and smooth with an average slope of 3±0.2° in most areas, facilitating long -distance traversal. Tens of impact craters with a diameter of 2-10 m with varying degrees of degradation can be seen in orbital images along this travers. Some show relatively high albedo and protuberant rims, and others have little relief, which makes it difficult to assess whether they are either primary or secondary impacts. Many rocks of various sizes (smaller than 2 m) are scattered on and around the exploration path. Over two million rocks with diameters ranging from 1.4 to 8m were also observed from the high-resolution imaging camera (HiRIC; 0.7 m/pixel) mosaics within the landing region. Some of the rocks seen by NaTeCam are clearly fluted, suggesting aeolian abrasion. Aeolian bed forms are also commonly found along the exploration path.
For more information on this interesting paper, see: https://pubs.geoscienceworld.org/gsa/geology/article-abstract/51/3/315/620359/Martian-soil-as-revealed-by-ground-penetrating
The Chinese rover, Tianwen-1, before it became dust bound, offered some tantalising clues about the Martian sub-surface detail and the possible reasons for their being covered by soil. Often times even the failures in exploration offer us critical clues concerning the explorations and what can be expected from future examinations. The increasing use of sub-surface radar along with its continuing miniaturisation will aid future Mars explorations - much as ground penetrating everywhere on Earth assists in archaeology, particularly in the exploration of Meso-American sites.
Also, recall that the term 'aeolian' refers to the wind and that aeolian abrasion means wind weathering with wind blown particulate matter causing the scouring of surface.
Hartmann352
Facebook
Twitter
Instagram