Mars is full of fascinating scars, the most prominent of which is impact crater. This new image from ESA’s Mars Express shows a particularly unusual example: an ancient triplet that contains not one, but three overlapping craters.
The crater triple rock is located in a particularly ancient place in the southern hemisphere of Mars, called Noachis Terra. This area was in a severe crater during the time of Noah (Nachian), an ancient era about 4 billion years ago in the history of Mars. During that time, a large number of asteroids and comets flew inward and hit the planet’s surface. Some of the features produced by these collisions are still intact on Mars today, because they were formed in the earliest stages of the solar system, so they are particularly interested in scientists seeking to learn more about our planetary neighbors and their past.
In the southern highlands of Mars, the signs of chaotic Noachian processes and events were especially clearly seen, filled with old, dilapidated volcanic craters. ESA’s “Mars Express” photographed many craters in the area, from the severely eroded Greeley Crater (named after American geologist Ronald Greeley) to the dune-patterned Newcomb Crater ( Named after a founder (and former principal) of the “Mars Express” mission, the spacecraft’s high-resolution stereo camera (HRSC) researcher, the camera responsible for taking this new image).
This image shows a triple crater located to the east of a famous feature called Le Verrier Crater, which spans nearly 140 kilometers. In contrast, the three depressions seen here are smaller. The largest span is 45 kilometers and the smallest is 28 kilometers.
How will such a crater triplet form? One possible explanation (and thought to be the most likely) is that the impactor split into three before hitting the ground, forming a trio of craters during the impact. Not all “multiple impactors” have such clear and neat features, many instead show elongated grooves, side-by-side non-circular depressions or basins that only partially overlap. Another explanation may be coincidence: at different points in time, three separate impactors may hit the surface of Mars at this location, cleverly superimposing the craters entirely by accident.
Interestingly, if the impactor does break and rupture, it may mean that the atmosphere of Noachian Mars is much denser than it is now and it is difficult to penetrate. This indicates that the early days of Mars were warmer and wetter than the cold and dry world we see today. Observations from numerous missions support this view and return evidence that water has flowed through the Red Planet in large amounts, revealing features such as the old network of river valleys and large lake basins believed to have formed during the Noah period.
Like many ancient and eroded craters in the southern highlands of Mars, the edges of these three craters are flattened, the ground is shallow, and they have been filled with sand for 4 billion years since their formation. There is also evidence of ice here-the smallest craters usually produce traces when ice and debris creep on the surface, similar to how a mixture of rock and glacier glaciers or debris-covered glaciers move in the high mountains of the earth.
The frame may have contained other craters, as shown by the circular spots on the concave surface in the upper right and lower left corners. In fact, despite the natural pits of Noachis Terra, on such an ancient terrain, the environment around the Triple Peak is surprisingly smooth. There are only a few small craters around that seem to have clear, sharp edges and bowl shapes, indicating that they are relatively young and have not yet begun to erode seriously. Overall, the older craters in the area seem to have “melted” to the surface, and this phenomenon is again attributed to ice.
As the ice beneath the surface of Mars flows and melts for millions of years, the soil becomes softer. This soft, ice-rich soil settles faster and fills pits and pits more easily, contributing to the smooth appearance of this part of Noachis Terra. This shows that, at least during Noah’s time, there must be a lot of water on Mars to produce a large amount of ice flow similar to glaciers.
Understanding the history of Mars and mapping the features that cover the Earth’s surface in detail are the main goals of Mars Express. Since its launch in 2003, the spacecraft has been exploring the “Red Planet” and is preparing to cooperate with many new missions that have or will join the Mars spacecraft. The ESA-Roscosmos ExoMars Trace Gas Orbiter (TGO) arrived in 2016, and the ExoMars Rosalind Franklin Rover and its accompanying ground science platform are scheduled to be launched in September 2022.
Together with the “Mars Express”, these missions will give full play to the characteristics of our neighbors and help us not only understand Mars, but by contrast, learn more about the history and nature of our home in the universe.
Crater Neukum is named after the founder of Mars Express
Provided by European Space Agency
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