It was a long journey for such a short stay. The Chinese probe was on November 23rd Chang’e 5 Launched from the Wenchang spaceport in southern China, the landing module touched down on the moon on Tuesday afternoon German time. Two days of sightseeing, i.e. taking photos of the area, packing souvenirs, namely soil samples, and on Thursday we should go back to lunar orbit, where the lander meets its mother ship. Relaxed travel looks different.
But it’s not a cultural holiday either, and the hectic pace is due to the construction: Because the lander is operated with solar power, everything has to be done within the two weeks in which this part of the moon receives sunlight. This does not tolerate any delay, as soon as the moonlit night falls, the module alone is helpless. It is China’s most demanding lunar mission to date. If it ends successfully, China would be only the third country after the USA and the Soviet Union to bring rock samples from the moon to earth; the first in four decades.
The docking maneuver becomes tricky
At least until Wednesday everything seems to have worked. According to Chinese state media, the device bored two meters into the lunar soil and took a sample from the depths. Dust and debris from the surface should also be taken along. The docking maneuver with the orbiter in the lunar orbit and of course the landing on earth are also tricky.
If that succeeds too, China has achieved another prestigious milestone. “In space technology, the return of samples belongs to the top class, after that only manned space flight comes,” says Ulrich Köhler, planetary geologist from the German Aerospace Center (DLR). China is hooked with that Chang’eProgram for years, one challenge after another. With Chang’e 6 Another sample-return mission is to follow, and Chinese taikonauts are set to set foot on the moon for the first time in the 2030s.
Scientists are also watching the flight with excitement. The mission could accomplish something that the Apollo-Program failed: to bring very old and very young moon rocks to earth for research.
The moon was formed around 4.5 billion years ago. A phase followed in which hot lava poured over the surface. In the meantime, the moon kept cooling down, today it is inactive. But when was the last volcanic eruption? Some researchers estimate that there hasn’t been much going on on the moon for around a billion years, others suspect much more recent eruptions. When lunar volcanism ended would be relevant not only to the history of the moon, but also to understanding planetary evolution.
This is why researchers are particularly pleased that the Mons Rümker volcanic massif was chosen as the landing site, where eruptions were still very late – you can tell from the samples when exactly. “True is Chang’e 5 now landed a little away from it, but it could be that the sample still contains very young rock, “says Koehler. Such material could provide new information about the history of the moon, but also a possible previous magnetic field or water stored in the rock in the form of hydroxyl molecules allow.