China is preparing to send a new spacecraft to its orbital station

Chinese Central Television announced that his country is preparing to launch a new cargo vehicle towards its national orbital station.

According to the available information, "China is preparing to send the Tianzhou-6 cargo vehicle to its orbital station in the first half of this May, so that this trip will be the first flight of a space cargo vehicle to the station since its official operation in December 2022."

The aforementioned vehicle will carry to the station 70 kg of fresh fruits, food, water, scientific test equipment, and many materials and items necessary for the astronauts to be there. It will also transport a quantity of xenon, which is used as a backup fuel for the electric propulsion systems at the station.

Tianzhou-6 is about 10.6 meters long, weighs 13.5 tons, and can transport 7.4 tons of cargo and payloads to Earth orbits.

The Chinese orbital station currently revolves around the Earth at an altitude of approximately 400 km, and China had indicated earlier that this station is supposed to operate for 10 years in space, on orbits between 340 and 450 km from Earth, and it was designed to have 3 people on board. Pioneers (or 6 Pioneers for a short period in the phase of replacing Pioneer crews), and this station will also be used for international space projects.

A Chinese rover discovers evidence of recent water activity on the Red Planet

The Chinese rover Zhurong has found evidence of liquid water at the low latitudes of Mars.

Scientists have long believed that Mars harbored abundant liquid water some three billion years ago. But dramatic weather changes have frozen much of it, as the ice is now trapped in plumes and has left much of the planet parched.

Now, the Zuurong rover has found evidence of water on sand dune surfaces on modern Mars by providing key observational evidence for liquid water at the low latitudes of Mars, according to a study led by Professor Chen Xiaoguang of the Institute of Geology and Geophysics (IGG) of the Chinese Academy of Sciences (CAS). CAS).

Researchers from the National Astronomical Observatories of the Chinese Academy of Sciences and the Academy's Institute of Atmospheric Physics participated in the study.

The latest findings, published in the journal Science Advances on April 28, from analysis of images and data sent home by Zurong and its orbital companion Tianwen 1 show that notable amounts of water from the planet's icy polar regions flowed into lower latitudes a few million years ago, and settled Over the dunes of Utopia Planitia.

Since landing in the northern hemisphere of Mars in May 2021, the rover has moved near four nearby crescent-shaped dunes in the "Utopia Planitia" region to verify the composition of their surface. All four of the wind-formed miniature geological features are covered with crusts and thin, rift grooves all around formed by the melting of small pockets of "modern water" sometime between 1.4 million years ago to 400,000 years ago, according to the new paper.

Previous studies provided evidence of a large amount of liquid water in early Mars, but as the early Martian atmosphere escaped during the later period, the climate changed dramatically.

The extremely low pressure and water vapor content make it difficult for liquid water to exist sustainably on Mars today. Hence, it was widely believed that water can only exist in solid or gaseous forms.

However, the droplets observed on the Phoenix robotic arm's camera prove that salty liquid water can appear in summer at present-day high latitudes on Mars.

Numerical simulations have also shown that suitable climatic conditions for liquid water can occur briefly in certain regions of Mars today.

So far, though, no evidence of liquid water has been shown at low latitudes on Mars. However, the results obtained from the Zuurong spacecraft fill in this gap.

The researchers used the data obtained by the Navigation and Terrain Camera (NaTeCam), the Multispectral Camera (MSCam) and the Mars Surface Composition Detector (MarSCoDe) on the Zuurong rover to study the various scale surface characteristics and physical compositions of the sand dunes in the landing area. On the southern edge of the plain "Utopia Planitia" (109.925 E, 25.066 N).

They found some important morphological features on the dune surfaces, such as ground crusts, grooves, granules, polygonal ridges and a ribbon-like effect.

Analysis of the spectral data revealed that the surface dune layer is rich in hydrated sulfates, hydrated silica (especially opal-CT), trivalent iron oxide minerals (especially ferrihydrate) and possibly chlorides.

Professor Xiaoguang said: “According to the meteorological data measured by the Zurong rover and other Mars astronauts, we concluded that these dune surface properties are related to the involvement of liquid brine formed from the subsequent melting of frost/snow falling on the salt-containing dune surfaces when the occurrence of cooling".

Specifically, salts in sand dunes cause frost/snow to melt at lower temperatures to form liquid, salty water. When the brine dries, hydrated sulfates, hydrated silica, iron oxide and other hydrated minerals precipitate sand particles to form sand aggregates and even crust. Then the shell cracks as a result of shrinkage.

Subsequent thaw/frost forms further polygonal ridges and streak-like traces on the surface of the crust.

The estimated age of the dunes (about 0.4-1.4 million years) and the relationship between the three phases of water indicate that the movement of water vapor from the polar ice sheet towards the equator during the large deflection phases in the late Martian Amazonian period led to the recurrence of moist environments at low latitudes. Therefore, a scenario for water activity was proposed, that is, cooling at low latitudes during the large tilt phases of Mars leads to frost / snow precipitation, and thus results in the formation of earth crusts and accumulations on the surface of salty sand dunes, thus solidifying the dunes and leaving traces of liquid brine activity.

This discovery provides key observational evidence for liquid water at the lower latitudes of Mars, where surface temperatures are relatively warmer and more suitable for life than at higher latitudes.

"This is important for understanding the evolutionary history of the Martian climate, searching for a habitable environment, and providing key clues for the future search for life," said Professor Chen.