China’s Chang’e-4 lunar rover has discovered an unusually colored, ‘gel-like’ substance during its exploration activities on the far side of the moon.
Because the space craft is solar powered, it has to switch off during a lunar night on the moon, during which there will be no sunlight.
The temperature on a lunar night is about -180°C (-292°F) and can get high during the day, where ‘insulating’ components like the gold coloured layers outside the lander and rover keep them cool.
Results of experiments from the mission could lead to new understandings of the challenges faced by settlers who may one day colonise our natural satellite.
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 is.
Day 8 started on July 25; Yutu-2 began navigating a path through an area littered with various small impact craters, with the help and planning of drivers at the Beijing Aerospace Control Center, according to a Yutu-2 ‘drive diary’ published on Aug. 17 by the government-sanctioned Chinese-language publication Our Space, which focuses on space and science communication.
On July 28, the Chang’e-4 team was preparing to power Yutu-2 down for its usual midday ‘nap’ to protect the rover from high temperatures and radiation from the sun high in the sky.
A team member checking images from the rover’s main camera spotted a small crater that seemed to contain material with a color and luster unlike that of the surrounding lunar surface.
The drive team, excited by the discovery, called in their lunar scientists. Together, the teams decided to postpone Yutu-2’s plans to continue west and instead ordered the rover to check out the strange material.
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 (VNIS), which detects light that is scattered or reflected off materials to reveal their makeup.
VNIS is the same instrument that detected tantalizing evidence of material originating from the lunar mantle in the regolith of Von Kármán crater, a discovery Chinese scientists announced in May.
So far, mission scientists haven’t offered any indication as to the nature of the colored substance and have said only that it is “gel-like” and has an “unusual color.” One possible explanation, outside researchers suggested, is that the substance is melt glass created from meteorites striking the surface of the moon.
Yutu-2’s discovery isn’t scientists’ first lunar surprise, however. Apollo 17 astronaut and geologist Harrison Schmitt discovered orange-colored soil near the mission’s Taurus-Littrow landing site in 1972, prompting excitement from both Schmitt and his moonwalk colleague, Gene Cernan.
Lunar geologists eventually concluded that the orange soil was created during an explosive volcanic eruption 3.64 billion years ago.
Chang’e-4 launched in early December 2018, and made the first-ever soft landing on the far side of the moon on Jan. 3. The Yutu-2 rover had covered a total of 890 feet (271 meters) by the end of lunar day 8.
The Chang’e-4 lander and Yutu-2 rover powered down for the end of lunar day 8 on Aug. 7, and began their ninth lunar day over the weekend. The Yutu-2 rover woke up at 8:42 p.m. EDT on Aug. 23 (00:42 GMT Aug. 24), and the lander followed the next day, at 8:10 p.m. (00:10 GMT).
During lunar day 9, Yutu-2 will continue its journey west, take a precautionary six-day nap around local noontime, and power down for a ninth lunar night around Sept. 5, about 24 hours hours ahead of local sunset.
A TIMELINE OF HOW CHINA REACHED THE FAR SIDE OF THE MOON
Chang’e-4 launched from the Xichang satellite launch centre in Sichuan, south-west China at 6:30 GMT on December 7
October 24, 2007 – China launches Chang’e-1, an unmanned satellite, into space where it remains operational for more than a year.
October 1, 2010 – China launches Chang’e-2. This was part of the first phase of the Chinese moon programme. It was in a 100km-high lunar orbit to gather data for the upcoming Chang’e-3 mission.
September 29, 2011 – China launches Tiangong 1.
September 15, 2013 – A second space lab, Tiangong 2, is launched.
December 1, 2013 – Chang’e-3 launched.
December 14, 2013 – Chang’e-3, a 2,600 lb (1,200 kg) lunar probe lands on the near side of the moon successfully. It became the first object to soft-land on the Moon since Luna 24 in 1976.
April 1, 2018 – Tiangong-1 crashes to Earth at 17,000mph and lands in the ocean off the coast of Tahiti.
May 20, 2018 – China launches a relay satellite named Queqiao which is stationed in operational orbit about 40,000 miles beyond the Moon. This is designed to enable Chang’e-4 to communicate with engineers on Earth.
The Chang’e-4 lunar rover is lifted into space from the Xichang launch centre in China’s southwestern Sichuan province on December 7