Chang'e-4, China's lunar rover, has recently explored the far side of the moon. As it dealt with its exploration activities, it stumbled across a strangely-colored 'gel-like' substance. 

On day 8 of its lunar exploration, Yutu-2, the mission's rover, discovered something as it moved its way at the far side of the moon. The discovery has prompted the scientists to postpone the rest of the driving plans for the rover to hopefully provide more time exploring the strange material that it found. The team decided to focus the instruments of the rover on gathering more information about this unusual material.

According to the Day 8 (July 25, 2019) Yutu-2 drive diary, it began navigating through an area at the far side of the moon that's littered with small craters. With the assistance from the drivers at the Beijing Aerospace Control Center, it was able to draw a path that led it to discover this unknown gel-like substance. On August 17, 2019, with the approval from the Chinese Government, Our Space, a government-sanctioned Chinese language publication, published the data that was collected on Day 8. 

On July 28, the Chang'e-4 team was preparing the rover to power down for its "midday nap". Such activity was to keep the rover protected from radiation and high temperature of the midday exposure to the sun. However, during this time, one of the team members who was checking the images from its main camera frame saw a small crater. What interested him was that it contained material with a luster and color that is far from the usual color of the surroundings in the lunar surface. 

Fueled with the excitement of what could have been a wonderful discovery, the driver team called in the experts on the lunar surface. Together, the team was able to decide to postpone the plan to explore the west side of the moon. Instead, the driver team was ordered to check on the substance to find out more about the strange material. 

With the assistance of its obstacle-avoidance cameras as well as its Visible Near-Infrared Spectrometer (VNIS), the rover was able to examine both areas by detecting light that is reflected and scattered off the materials to reveal what they are made of. So far, the team of scientists that examined the material has yet to reveal the nature of the colored substance.

Outside researchers have offered possible explanations as to what the substance could be. Some say that it is melt glass created from meteorites that hit the surface of the moon. This discovery isn't the first lunar surprise, but its lack of clear identification makes it rather interesting. 

Chang'e-4 was launched into space on December 3, 2018, and made a soft landing on the lunar surface on June 3, 2019.