The Chang’e 4 lander and the Yutu 2 rover are currently in hibernation mode, sitting out the frigid lunar night, which lasts for about two Earth weeks. The Chinese mission to explore the lunar far side is now well into overtime, lasting longer than initially intended.
China’s Chang’e 4 mission has gone about as well as could be expected, if not better. The probe landed in the 115-mile-wide (186 kilometers) Von Kármán Crater on January 3, 2019, which is on the Moon’s far side near its south pole.
The lander, along with its companion, the Yutu 2 rover, are investigating geological and chemical differences between the near and far sides of the Moon. Our Moon is tidally locked to Earth, forcing us to gaze perpetually upon one of its faces. With all due respect to Pink Floyd, there is no “dark side” of the moon, as both sides experience days and nights.
Chang’e 4 and Yutu 2 have now survived four lunar days and nights, or about 29.5 days on Earth (the lunar day and night are split about equally in terms of length, at just slightly over 14 days each). As of April 12, the duo is back in hibernation mode, sitting out its fifth lunar night, reports the Planetary Society. The mission was designed to last for three lunar days, according to Space.com, so everything since late March has been a bonus for the China National Space Administration (CNSA). Should the lander and rover survive the fifth lunar night, a fifth lunar day of exploration starting on April 28 would be a distinct possibility.
The Yutu 2 rover has now traveled a total of 178.9 meters (587.9 feet), according to the Lunar Exploration and Space Program Center of the CNSA, and as relayed by Chinese state media Xinhua. This distance far exceeds the lunar terrain covered by its predecessor, Yutu 1, during the Chang’e 3 mission, which managed to travel 114 meters before fizzling out in February 2014.
During the fourth lunar day, Yutu 2 traveled 8 meters from March 29 to April 1. The duo was then placed into a daytime hibernation mode until April 8 to prevent the devices from getting scorched by the Sun. Yutu 2 then managed to explore another 8 meters from April 8 to 12 before going back to sleep as the fifth lunar night of the mission set in. As Andrew Jones from the Planetary Society reports, there
was no initial indication as to why Yutu-2 had covered relatively little ground in day 4, but Chang’e-4 chief designer Sun Zezhou told an audience at Nanjing University of Aeronautics and Astronautics on 11 April that the rover had been carefully navigating the area in order to approach and analyze specimens with its visible and infrared spectrometer (VNIS), similar to activities it performed during day 3.
So slow and steady progress, with CNSA officials reporting that all elements of the Chang’e 4 mission, including the Queqiao relay satellite in orbit around the Moon, are working nominally.
Aside from these details, and some cool new images captured by Yutu 2's panoramic camera, there isn’t much else to report. Actual scientific data is still forthcoming, and we should expect to hear news in this regard during the Lunar and Deep Space Exploration conference, which will be held in Zhuhai, China in July.