China’s Yutu-2, or Jade Rabbit-2, became the longest-working lunar rover on the Moon when it started to work for the 13th lunar day on the far side of the Moon.
The previously record was held by Lunokhod 1, the robotic rover of the former Soviet Union that became the world’s first to be sent to the Moon in 1970, where it worked for about 10 months, CGTN online reported.
China’s Chang’e-4 probe, including a lander and Yutu-2 launched on December 8, 2018, made the first-ever soft landing on the Von Karman Crater in the South Pole-Aitken Basin on the far side of the Moon on January 3, 2019.
Both the lander and rover have resumed work for the 13th lunar day after laying dormant during the extremely cold night, according to the Lunar Exploration and Space Program Center of the China National Space Administration.
The lander woke up at 5:14 am Saturday (Beijing time), and the rover awoke at 6:43 pm Friday. Both are in normal working order.
The rover has driven more than 345 meters on the far side of the Moon to conduct a scientific exploration of the virgin territory.
A lunar day equals 14 days on Earth, a lunar night is of the same length. The Chang’e-4 probe switches to dormant mode during the lunar night due to a lack of solar power.
The scientific tasks of the Chang’e-4 mission include conducting low-frequency radio astronomical observation, surveying the terrain and landforms, detecting the mineral composition and shallow lunar surface structure and measuring neutron radiation and neutral atoms.
The Chang’e-4 mission embodies China’s hope to combine wisdom in space exploration with four payloads developed by the Netherlands, Germany, Sweden and Saudi Arabia.
In late July, early August, Chang’e-4 lunar discovered an unusually colored, “gel-like” substance during its exploration activities on the far side of the moon.
The mission’s rover, Yutu-2, stumbled on that surprise during lunar day 8. The discovery prompted scientists on the mission to postpone other driving plans for the rover, and instead focus its instruments on trying to figure out what the strange material was.
With the help of obstacle-avoidance cameras, Yutu-2 carefully approached the crater and then targeted the unusually colored material and its surroundings. The rover examined both areas with its Visible and Near-Infrared Spectrometer, which detects light that is scattered or reflected off materials to reveal their makeup.
It could be that the substance is melted glass which was deposited onto the moon’s surface by a meteorite, but so far, Chinese space officials have made no announcement, as to what the mysterious substance could be.
Dan Moriarty, NASA Postdoctoral Program Fellow at the Goddard Space Flight Center in Greenbelt, Maryland, commented that it was hard to make a definitive assessment of the substance’s chemical composition, given the quality of the Yutu-2 image.
Moriarty told Space.com that the outlined material appears somewhat brighter than surrounding materials, though the actual brightness is hard to confirm from the photographs. If so, the contrast could be due to the differing origins of the respective materials.
“Chang’e-4 landed in a mare basalt-filled crater, which is typically dark,” Moriarty said. “Highlands crustal materials are typically brighter, so that would be a potential candidate.”
“It will be very interesting to see what the spectrometer sees, and if any higher-resolution images become available,” Moriarty noted
Clive Neal, a lunar scientist at the University of Notre Dame, told Space.com that, based on the image, the material highlighted in the center of the crater resembles a sample of impact glass found during the Apollo 17 mission in 1972. Sample 70019 was collected by astronaut Harrison Schmitt, a trained geologist, from a fresh crater 10 feet (3 meters) in diameter, similar to that approached by Yutu-2.
Neal describes 70019 as being made of dark, coherent microbreccia — broken fragments of minerals cemented together — and black, shiny glass. “I think we have an example here of what Yutu-2 saw,” Neal said.
High-speed impacts on the lunar surface melt and redistribute rock across the craters they make and can create glassy, igneous rocks and crystalline structures.