FILE: China - Exact Date, Location Unknown (National Astronomical Observatories of China - No access Chinese mainland)
1. Animation of China's Chang'e-4 probe landing on Moon
2. Animation of lunar rover Yutu-2 working

Beijing, China - Feb 26, 2020 (National Astronomical Observatories of China - No access Chinese mainland)
3. Image of subsurface structure of far side of Moon

Beijing, China - Feb 26, 2020 (CCTV - No access Chinese mainland)
4. SOUNDBITE (Chinese) Su Yan, researcher, National Astronomical Observatories of China (NAOC) (starting with shot 3/ending with shot 5):
"The first layer is a fine 12-meter soil layer below the surface. The second layer between 12 and 24 meters under the ground has a lot of stones and the strongest radar echo. It even forms a stone layer and stacks of loose stones. There are three gravel stacks. The third layer is 24-40 meters under the surface. Radar echo shows its dark and bright parts, so there are granules and scattered stones."

Beijing, China - Feb 26, 2020 (National Astronomical Observatories of China - No access Chinese mainland)
5. Image of subsurface structure of far side of Moon

Beijing, China - Feb 26, 2020 (CCTV - No access Chinese mainland)
6. SOUNDBITE (Chinese) Li Chunlai, deputy director, NAOC (ending with shots 7-9):
"We find the ejecta have many layers and each layer is different from each other. It may mean the place has lots of ejecta from impact sites, so history of meteorite impacts here is very complicated. It also shows the Moon was frequently struck by small celestial bodies, and debris will be ejected to bottom of the Von Karman Crater. The ejecta have recorded history of meteorite impact on the Moon."
7. Image showing route of lunar rover Yutu-2
8. Researchers studying route of lunar rover Yutu-2
9. Various of Li, Su discussing subsurface structure of far side of Moon
10. Su introducing subsurface structure of far side of Moon to reporter
11. Subsurface structure of far side of Moon
12. SOUNDBITE (Chinese) Li Chunlai, deputy director, NAOC (partially overlaid with shot 13):
"We hope it can walk out of the ejecta-covered area. If it can enter a basalt zone, maybe we can better understand distribution and structure of ejecta from meteorite impacts. The distance may be 1.8 kilometers. I think it may take another one year for the rover to walk out of the ejecta-covered area."
++SHOT OVERLAYING SOUNDBITE++
13. Image of lunar rover Yutu-2
++SHOT OVERLAYING SOUNDBITE++

Beijing, China - Feb 26, 2020 (National Astronomical Observatories of China - No access Chinese mainland)
14. Animation of lunar rover Yutu-2 moving on Moon

China's lunar rover Yutu-2, or Jade Rabbit-2, has helped scientists unveil the secrets buried deep under the surface on the far side of the Moon, enriching human's understanding about the history of celestial collision and volcanic activities and shedding new light on the geological evolution on the Moon.

China's Chang'e-4 probe made the first-ever soft landing on the eastern floor of the Von Karman Crater within the South Pole-Aitken Basin on the far side of the Moon on Jan 3, 2019. After its landing, the spacecraft immediately deployed its Yutu-2 rover, which uses Lunar Penetrating Radar (LPR) to investigate the underground it roams.

A study conducted by a research team led by Li Chunlai and Su Yan at the National Astronomical Observatories of China (NAOC) reveals what lurks below the lunar surface.

As a result of the tidal locking effect, the Moon's revolution cycle is the same as its rotation cycle, and the same side always faces Earth.

The research team used the LPR on Yutu-2 to send radio signals deep into the surface of the Moon, reaching a depth of 40 meters by the high-frequency channel of 500 MHz - more than three times the depth previously reached by the Chang'e-3 lunar probe, which was sent to the near side of the Moon at the end of 2013.

The results of the radar data collected by the LPR during the first two lunar days (a lunar day equals 14 days on Earth) of operation provide the first electromagnetic image of the subsurface structure of the far side of the Moon and the first "ground truth" of the stratigraphic architecture of an ejecta deposit, said Li Chunlai, deputy director of the NAOC.

"The first layer is a fine 12-meter soil layer below the surface. The second layer between 12 and 24 meters under the ground has a lot of stones and the strongest radar echo. It even forms a stone layer and stacks of loose stones. There are three gravel stacks. The third layer is 24-40 meters under the surface. Radar echo shows its dark and bright parts, so there are granules and scattered stones," said Su Yan, a researcher from the NAOC.

The scientists analyzed the radar image with tomographic technique, and the result shows that the subsurface is essentially made by highly porous granular materials embedding boulders of different sizes.

The content is likely the result of a turbulent early solar system, when meteors and other space debris frequently struck the Moon. The impact site would eject material to other areas, creating a cratered surface atop a subsurface with varying layers, said Li.

"We find the ejecta have many layers and each layer is different from each other. It may mean the place has lots of ejecta from impact sites, so history of meteorite impacts here is very complicated. It also shows the Moon was frequently struck by small celestial bodies, and debris will be ejected to bottom of the Von Karman Crater. The ejecta have recorded history of meteorite impact on the Moon," said Li.

As the Yutu-2 rover has walked about 300 meters, Li said his team expects new discovery in the future.

"We hope it can walk out of the ejecta-covered area. If it can enter a basalt zone, maybe we can better understand distribution and structure of ejecta from meteorite impacts. The distance may be 1.8 kilometers. I think it may take another one year for the rover to walk out of the ejecta-covered area," Li said.

The study was published Wednesday in the latest issue of Science Advances.