May 8, 2024

China’s Zhurong Mars Rover Finds Evidence of Water in Martian Sand Dunes

Researchers from the National Astronomical Observatories of CAS and the Institute of Atmospheric Physics of CAS were also involved in the research study.
Water traces on bright sand dunes. (a) Topographic shape map of the environs where the trace is located. The coordinate system is east-north-up (ENU) regional Cartesian coordinate and the origin is that of the rover coordinate system. The background Digital Orthophoto Map (DOM) picture was taken by NaTeCam. (b) MSCam birds- eye-view picture showing a strip-like trace and a likely water-soaked fragmented soil block. (c) Enlarged image revealing polygonal cracks and brilliant polygonal ridges. (d) Enlarged photo showing circular area with the strip-like trace as a part. (e) NaTeCam 3D picture of an interdune anxiety between 2 dark longitudinal dunes. (f) A cross-section of the dune along the profile of the white dash line in (e). Credit: IGGCAS
Previous studies have offered evidence of a large quantity of liquid water on early Mars, but with the escape of the early Martian atmosphere throughout the later period, the environment altered dramatically. Extremely low pressure and water vapor material make it challenging for liquid water to sustainably exist on Mars today. Hence, it has actually been extensively believed that water can only exist there in gaseous or solid types.
Droplets observed on the Phoenixs robotic arm show that salty liquid water can appear in the summertime at existing high latitudes on Mars. Mathematical simulations have actually also revealed that climatic conditions appropriate for liquid water can quickly occur in certain areas of Mars today. Till now, however, no proof has shown the presence of liquid water at low latitudes on Mars.
Now, nevertheless, findings from the Zhurong rover fill the gap. The Zhurong rover, which is part of Chinas Tianwen-1 Mars exploration objective, successfully landed on Mars on May 15, 2021. The landing site is situated at the southern edge of the Utopia Planitia (UP) Plain (109.925 E, 25.066 N), where the northern lowlands system is located.

The researchers used data gotten by the Navigation and Terrain Camera (NaTeCam), the Multispectral Camera (MSCam), and the Mars Surface Composition Detector (MarSCoDe) aboard the Zhurong rover to study the different-scale surface area features and material structures of dunes in the landing area.
They found some essential morphological functions on the dune surfaces, such as crusts, fractures, granulation, polygonal ridges, and a strip-like trace. The analysis of spectral data revealed that the dune surficial layer is rich in hydrated sulfates, hydrated silica (specifically opal-CT), trivalent iron oxide minerals (particularly ferrihydrite), and possibly chlorides.
” According to the determined meteorological information by Zhurong and other Mars rovers, we presumed that these dune surface qualities were associated with the participation of liquid saline water formed by the subsequent melting of frost/snow falling on the salt-containing dune surface areas when cooling occurs,” stated Prof. Qin.
Specifically, salts in dunes cause frost/snow to melt at low temperatures to form salted liquid water. When the saline water dries, the precipitated hydrated sulfate, opal, iron oxide, and other hydrated minerals cement sand particles to form sand aggregates and even crust. The crust is more split by shrinking. The later frost/snow melting process further forms polygonal ridges and a strip-like trace on the crust surface.
The approximated age of the dunes (about 0.4– 1.4 million years) and the relationship amongst the three phases of water recommend that the transfer of water vapor from the polar ice sheet toward the equator throughout the large obliquity stages of Marss late Amazonian period resulted in duplicated humid environments at low latitudes. A circumstance of water activity has actually been proposed, i.e., cooling at low latitudes during Marss big obliquity phases triggers frost/snow to fall and subsequently results in the formation of crusts and aggregates on the salty dune surface area, therefore strengthening dunes and leaving traces of liquid saline water activity.
The discovery provides essential observational evidence of liquid water at Martian low latitudes, where surface area temperatures are fairly warmer and more appropriate for life than at high latitudes.
” This is crucial for understanding the evolutionary history of the Martian environment, looking for a habitable environment, and offering key hints for the future look for life,” stated Prof. Qin.
Recommendation: “Modern water at low latitudes on Mars: Potential evidence from dune surfaces” by Xiaoguang Qin, Xin Ren, Xu Wang, Jianjun Liu, Haibin Wu, Xingguo Zeng, Yong Sun, Zhaopeng Chen, Shihao Zhang, Yizhong Zhang, Wangli Chen, Bin Liu, Dawei Liu, Lin Guo, Kangkang Li, Xiangzhao Zeng, Hai Huang, Qing Zhang, Songzheng Yu, Chunlai Li and Zhengtang Guo, 28 April 2023, Science Advances.DOI: 10.1126/ sciadv.add8868.

Previous research studies have supplied proof of a big quantity of liquid water on early Mars, but with the escape of the early Martian environment during the later duration, the climate altered drastically. Really low pressure and water vapor content make it difficult for liquid water to sustainably exist on Mars today. Droplets observed on the Phoenixs robotic arm prove that salted liquid water can appear in the summer at present high latitudes on Mars. Till now, however, no evidence has shown the existence of liquid water at low latitudes on Mars.
Specifically, salts in dunes cause frost/snow to melt at low temperatures to form salty liquid water.

A selfie taken by the Zhurong rover alongside its landing platform, recorded with a wireless video camera. Credit: Chinese National Space Administration
The Zhurong rover, part of Chinas Tianwen-1 Mars objective, has actually found evidence of liquid water at low Martian latitudes, suggesting potentially habitable environments. This discovery, contradicting previous beliefs that water might just exist in gaseous or solid states on Mars, was made by evaluating morphological features and mineral compositions of dunes in the landing area.
The Zhurong rover has found proof of water on dune surface areas on modern-day Mars by offering essential observational proof of liquid water at low Martian latitudes, according to a research study led by Prof. Xiaoguang Qin from the Institute of Geology and Geophysics (IGG) of the Chinese Academy of Sciences (CAS).
The study was released on April 28 in the journal Science Advances.