Chang'e 6 brought rock from the far side of the moon to Earth – a planetary scientist explains what this sample could contain

China achieved a historic feat by bringing back the very first sample from the back of the moon in June 2024. It is a lunar lander, Chang'e 6collected about 2 kilograms of rock and soil using a robotic shovel and drill. These samples returned to Earth on June 25, 2024.

Chang'e 6 built on the achievements of two previous Chinese missions: Chang'e 4which landed gently on the far side of the moon and used a rover to explore the surface, and Chang'e 5which brought back samples from the Earth-facing side of the Moon.

Scientists expect the Chang'e-6 samples to not only provide vital geological insights concerning the moon, but additionally improve their understanding of Earth and the early history of the solar system.

Moon researchers like me have been fascinated by the far side of the moon for the reason that Soviet Union. Luna 3 mission in 1959, which showed that the back side of the moon looks completely different from the front side.

The back of the moon

Since the identical side of the moon at all times faces the earth, the back side can only be seen with a spaceship. The back side shouldn’t be permanently dark – it alternates between two weeks of daylight and two weeks of nightjust like several other place on the moon.

Images from space probes show that approx. one third of the surface of the earth-facing side of the moon it consists of dark, smooth planeswhile only about 1% of the opposite side has these levels.

These dark plains were once volcanic lava flows, much like those on Earth in Hawaii, Eastern Washington and India.

Images from the lunar orbit tell the researchers that These plains once had Volcanic vents, cones, domes, collapsed pits and channels.

Only the Chang'e 4 and Chang'e 6 missions have landed on the far side of the moon, while 25 spacecraft have successfully made soft landings on the front side. A landing mission on the far side is tougher because mission control cannot directly see or communicate with the spacecraft. So what is required is a second spacecraft to relay information between the lander and Earth. China used its orbiting satellite Queqiao-2which was launched in March 2024.

The touchdown of Chang'e 6

On June 6, 2024 Chang'e 6 landed throughout the colossal South Pole-Aitken Basinwhich is about 2,500 km wide and eight km deep. It is the most important impact structure within the solar system: a bowl-shaped structure that’s created when an asteroid collides with a body, causing a large explosion.

Above the South Pole-Aitkin lies a rather younger and far smaller impact structure called Apollo Basinabout 308 miles (492 km) in diameter.

Impact basin expose the deep interior of the Moon like a drill core. For example, the impact that created the South Pole-Aitkin Basin can have removed a few of the Moon's crust and exposed materials deep contained in the Moon – as much as 100 km deep. The subsequent Apollo impact would then have removed much more material. So the samples brought back will likely contain some rocks which can be different from those in the present sample collection.

Chang'e 6 landed here on a few of the sparse volcanic deposits on the far side. Analyzing the composition of the volcanic rocks that Chang'e 6 brought back could help researchers determine why the front so many more volcanic deposits. Scientists can even have the option to check the age of those rocks on the back with rocks from volcanic eruptions on the front, that are about 3.9 to three.2 billion years ago.

Determining the actual age of the rocks will help scientists refine other methods, like crater countingthat are used to estimate the age of surface formations on planets.

Because planetary surfaces accumulate more craters the longer they exist, researchers can estimate the age of a planetary surface by comparing the variety of craters they’ll count with those generated by a simulated model. But counting craters shouldn’t be very accurate—real rock samples can assist researchers determine how they improve these methods.

Uncovering secrets from the moon's molten past

Researchers suspect that the moon, together with some rocky planets, had previously almost completely meltedFor a transient period in early history, the Moon consisted only of lava and little or no solid rock.

The landing site of Chang'e 6 could Materials from the lunar mantle – the layer beneath the crust. These samples could help scientists understand how the Moon evolved from a magma ocean into geological layers – a solidified crust, a mantle and a core.

Data from these samples could also provide clues concerning the Earth's evolution throughout the final stages of planet formation. Scientists consider that many asteroids and comets hit Earth about 4 billion years ago. Rocky planets just like the Earth. We call this era the “Lunar Cataclysm” Period. Studying certain rocks from crater impacts on the Moon could help scientists learn more about this era.

Since the South Pole-Aitkin Basin is the oldest well-preserved structure on the Moon and should hold clues as as to if the variety of basin-forming impacts occurred over an extended time period, about 500 million years, or a shorter time period, about 200 million years. Knowing the timeframe would help estimate the intensity of impacts throughout the formation of the Solar System.

A scientific gift from the opposite side

Extraterrestrial materials – corresponding to samples from the moon, Mars, Asteroids And Comets – are gifts that at all times bring joy.

Scientists will look after and store these samples in laboratories to preserve them of their original form, releasing a few of the precious samples for evaluation using state-of-the-art equipment, and preserving the remaining for future generations of scientists to analyze recent questions many years from now.

Science makes the best progress when scientists share ideas, data and samples. At the tip of 2023, the China National Space Administration will launch Examples from Chang'e 5 available for a spread of international researchers. I expect there will probably be an analogous sample exchange program for the Chang'e 6 samples.

However, this exchange doesn’t go in each directions. NASA cannot share the samples it manages directly with Chinese researchers because Wolf Amendmentwhich prohibits NASA from using funds to cooperate with China on any programs.

China’s future plans for lunar exploration include Chang'e 7 and eight missionsplanned for 2026 and 2028 respectively. These missions will land on the South Pole to go looking for water ice, carbon dioxide ice – also called dry ice – and methane in ice form. The recently canceled NASA VIPER Rover had similar goals. These missions will help China determine where to construct its International Lunar Research Station, planned for 2030.