Tianwen-1: Zhurong rover finds evidence of water at low latitudes on modern Mars

The Zhurong rover has discovered proof of water on dune surfaces on fashionable Mars by offering key observational proof of liquid water at low Martian latitudes, in response to a research led by Prof. Qin Xiaoguang from the Institute of Geology and Geophysics (IGG) of the Chinese language Academy of Sciences (CAS).

Researchers from the Nationwide Astronomical Observatories of CAS and the Institute of Atmospheric Physics of CAS have been additionally concerned within the research. The research was printed in Science Advances on April 28.

Earlier research have supplied proof of a considerable amount of liquid water on early Mars, however with the escape of the early Martian environment in the course of the later interval, the local weather modified dramatically. Very low stress and water vapor content make it troublesome for liquid water to sustainably exist on Mars right now. Thus, it has been extensively believed that water can solely exist there in stable or gaseous kinds.

Nonetheless, droplets noticed on the Phoenix’s robotic arm show that salty liquid water can seem in the summertime at present excessive latitudes on Mars. Numerical simulations have additionally proven that weather conditions appropriate for liquid water can briefly happen in sure areas of Mars right now. Till now, although, no proof has proven the presence of liquid water at low latitudes on Mars.

Now, nevertheless, findings from the Zhurong rover fill the hole. The Zhurong rover, which is a part of China’s Tianwen-1 Mars exploration mission, efficiently landed on Mars on Could 15, 2021. The landing site is positioned on the southern fringe of the Utopia Planitia (UP) Plain (109.925 E, 25.066 N), the place the northern lowlands unit is positioned.

The researchers used information obtained by the Navigation and Terrain Digicam (NaTeCam), the Multispectral Digicam (MSCam), and the Mars Floor Composition Detector (MarSCoDe) aboard the Zhurong rover to review the different-scale floor options and materials compositions of dunes within the touchdown space.

They discovered some essential morphological options on the dune surfaces, equivalent to crusts, cracks, granulation, polygonal ridges, and a strip-like hint. The evaluation of spectral information revealed that the dune surficial layer is wealthy in hydrated sulfates, hydrated silica (particularly opal-CT), trivalent iron oxide minerals (particularly ferrihydrite), and presumably chlorides.

“In response to the measured meteorological information by Zhurong and different Mars rovers, we inferred that these dune floor traits have been associated to the involvement of liquid saline water fashioned by the next melting of frost/snow falling on the salt-containing dune surfaces when cooling happens,” stated Prof. Qin.

Particularly, salts in dunes trigger frost/snow to soften at low temperatures to kind salty liquid water. When the saline water dries, the precipitated hydrated sulfate, opal, iron oxide, and different hydrated minerals cement sand particles to kind sand aggregates and even crust. Then the crust is additional cracked by shrinkage. The later frost/snow melting course of additional kinds polygonal ridges and a strip-like hint on the crust floor.

The estimated age of the dunes (about 0.4–1.4 million years) and the connection among the many three phases of water recommend that the switch of water vapor from the polar ice sheet towards the equator in the course of the giant obliquity levels of Mars’s late Amazonian interval led to repeated humid environments at low latitudes. Subsequently, a state of affairs of water exercise has been proposed, i.e., cooling at low latitudes throughout Mars’s giant obliquity levels prompts frost/snow to fall and subsequently ends in the formation of crusts and aggregates on the salty dune floor, thus solidifying dunes and leaving traces of liquid saline water exercise.

The invention gives key observational proof of liquid water at Martian low latitudes, the place floor temperatures are comparatively hotter and extra appropriate for all times than at excessive latitudes.

“That is essential for understanding the evolutionary historical past of the Martian local weather, in search of a liveable surroundings, and offering key clues for the longer term seek for life,” stated Prof. Qin.