For the first time in nearly half a century, scientists will get their hands on new moon rocks.
The Chinese space agency’s Chang’e-5 spacecraft, which landed on the moon on December 1 at 10:15 a.m. EST, will pick up lunar soil from a never-before-visited region and bring it back to earth a few weeks later. These samples could provide details about an era of lunar history unaffected by previous lunar missions.
“We’ve talked since the Apollo era about going back and collecting more samples from another region,” says planetary scientist Jessica Barnes of the University of Arizona at Tucson, who is using lunar samples from missions in the United States and the Soviet Union USA works 1960s and 1970s. “It’s finally happening.”
Chang’e-5, the latest in a series of missions named after the Chinese moon goddess (SN: 11.11.18) took off on November 23 from the launch site of the China National Space Administration in the South China Sea and landed in volcanic plains in the northwest near the moon.
Equipped with a shovel and a drill, the lander will collect about two kilograms of earth and small stones, possibly up to two meters below the surface of the moon, says planetary scientist Long Xiao of the Chinese University of Geosciences in Wuhan.
The spaceship has to work fast. Without an internal heating mechanism, it has no defenses against the extremely cold moonlit night, which can reach -170 ° Celsius. The entire mission has to fit within one lunar day, roughly 14 earth days.
After the lander collects the sample, a small rocket may bring the lander and sample back to the orbiter as early as December 3, although the Chinese space agency has not released the official schedule.
In orbit, the moon material is packed in a return capsule and sent back to Earth. The capsule is expected to land in the Inner Mongolia region on December 17.
The last time new lunar samples were sent back to Earth was in 1976, with the end of the Soviet Union’s Luna program. Between these missions and NASA’s Apollo missions, scientists on Earth will have to examine around 380 kilograms of lunar material (SN: 07/15/19). “Maybe when it came to the moon, people thought for a long time that they did that,” says Barnes.
Two kilograms of new stuff may not sound like much besides what’s already in hand. But Chang’e-5 is returning samples from a completely unexplored region. The landing site is in the Mons Rümker region in the northwest near the moon. Like the landing sites Apollo and Luna, Rümker is flat. “The technical consideration is first to be sure,” says Xiao.
All Apollo and Luna missions visited ancient volcanic plains where the rocks are between 3 and 4 billion years old. Rümkers volcanic rocks are much younger and around 1.3 to 1.4 billion years old. In the 1960s, scientists did not believe that the moon was volcanically active that late. Recent studies from lunar orbit and telescopes have suggested a more complicated volcanic past.
“With these new samples, we may add another point in our lunar geological history,” says Barnes. “We will get an idea of what the volcanic history of the moon was like a billion years ago. We have no access to that in the samples that have already been returned.”
The Rümker region is also rich in potassium, rare earth elements and phosphorus, often referred to as KREEP elements. These elements were some of the last to crystallize out of the magma ocean that covered the young moon and can help reveal details about how this process went. There’s an “exotic taste” of material, says Barnes. “Geochemically, it’s a very different area than the rest of the moon.”
One of the greatest challenges for the mission will be drilling this material. The drill cannot change direction after use. Hence, he has to try to pierce everything directly below. If the drill hits a large rock, it can fail. So the Chang’e 5 team is hoping for fine, loose soil, says Long.
Once the sample is back on earth, it will be stored and cataloged at a curation center in Beijing. Then it is distributed to scientists to do research there.
“On missions like this, you can’t breathe easily until the samples are back and safe in the curation location they’re supposed to be kept,” says Barnes.
The Chinese space agency plans to share samples with international scientists. A 2011 congressional rule made it difficult for US scientists to work directly with China. It is therefore unclear who will be working with the rocks. However, the discoveries that the new samples will enable go beyond international borders.
“It doesn’t matter who does it,” says Barnes. “The whole world should be behind this mission and pursuit. It’s a piece of history. “