NASA’s Mars rover Opportunity continues to detect surprises on the surface of the Red Planet, and recent finds of the rover include what might be “stone strips” well known to geologists.
The texture of the ground, observed on recent images made by this rover, resembles a blurry version of very clear stone bands observed on the slopes of some mountains on Earth, which are formed as a result of repeated cycles of freezing and thawing of moist soil. However, among the possible reasons for the emergence of these structures, scientists call the wind, the movement of material down the slope, other processes or their combinations.
The Opportunity rover landed on the surface of Mars in January 2004. On the 5th Martian day (called sols) from the day of planting, the rover began to study the canal called the Valley of Perseverance, descending down the inner slope of the western part of the Endeavor crater crest.
On the slopes of this valley, the Opportunity rover discovered amazing structures that consisted of alternating narrow bands of small stones and fine material, close to the factional composition to the sand, parallel to the slope.
The origin of the valley itself is still unclear to scientists. Members of the scientific team of the mission of Opportunity analyze various variants of its origin, including the action of water, wind or ice.
On Earth, stone strips are formed by the following mechanism, a well-known scientist. Soils, which are a mixture of silt and clay, sand and small stones, experience a larger volume expansion in those areas where the content of fine material holding more water is greater. When freezing, the water expands, and larger particles, small stones, are pushed upward. These large particles then descend along the slope, forming long strips alternating with strips of fine-grained ground material.