[ad_1]
This process may be more complex than scientists previously thought, a team from the Institute of Geochemistry of the Chinese Academy of Sciences in Guiyang reported in the journal Matter and Radiation at Extremes last month.
01:28
China’s Chang’e 5 lunar exploration mission returns to Earth with lunar samples
China’s Chang’e 5 lunar exploration mission returns to Earth with lunar samples
“This unique mineral likely formed in the Aristarchus crater and then erupted north to the Chang’e 5 mining site,” said Du Wei, lead author of the paper.
“Our study was a reminder that nature often works in more complex ways than we simulate in the laboratory,” she told the South China Morning Post by phone on Thursday.
Seifertite, which forms under high pressure and temperature, is one of the densest and hardest forms of silica found in nature.
Seifertite, which has the same chemical composition as quartz, had previously been found only in meteorites from Mars and the Moon.
Du said it could be synthesized by placing quartz under 100 gigapascals of pressure, the pressure found 3,400 km deep in the Earth’s core.
Seifertite was discovered in samples from Chang’e 5 in 2022 by Du and colleagues from Guiyang, who published the discovery in Geophysical Research Letters.
Analysis of a 30mg sample distributed by the China National Space Administration detected the presence of sifertite and stishovite, a silicon dioxide that is even denser than sifertite.
“We were so surprised that we used multiple methods to confirm that it was sifertite,” Du said.
Seifertite may have formed during a collision, but scientists say its existence is because the collision generates high temperatures that destabilize the mineral and tend to regress into other forms. I have a problem with this.
Further analysis led the researchers to believe that the formation process on the Moon is different from how sifertite is produced in the laboratory.
In the new paper, Du’s team focused on analyzing the formation and origin of sifertite, which they discovered two years ago.
The moon’s sifertite probably did not originate directly from quartz, its stable and most common form, Du said. Instead, she said, some intermediate structures, such as so-called alpha-cristobalite, helped the process.
“When the collision occurred, the pressure required to transform the more common alpha-cristobalite into cyfertite was only 11 gigapascals,” Du said. “Then, as the temperature continued to rise, some of the sifertite transformed into stishovite,” she added.
The Chang’e 5 landing site is dominated by volcanic rock known as basalt, so the rare silica material was probably transported from nearby regions rather than produced locally, he said.
China launches relay satellite that will enable communication with the far side of the moon
China launches relay satellite that will enable communication with the far side of the moon
Based on the pressures and timescales required for Seifertite’s formation, the researchers determined that Seifertite originated from a crater between 3km and 32km (1.8 to 20 miles) in diameter, depending on the impact angle. .
Remote sensing data from previous lunar exploration missions showed four potential craters. Among them, Aristarchus is the youngest and therefore the most likely source.
“The crater has to be very young to avoid later being covered by lava or something like that,” she says.
Next, Du’s team will focus on basalt, hoping to solve one of the biggest mysteries raised by the Chang’e 5 samples. Why was the moon still active two billion years ago, when many believed it had cooled to death?
Impact craters shaped the moon’s Swiss cheese-like appearance that we see today, but its evolution was primarily driven by internal geological processes such as volcanic eruptions, Du said.
01:42
China’s lunar lander Chang’e 5 finds water on the moon, but not as much as expected
China’s lunar lander Chang’e 5 finds water on the moon, but not as much as expected
“We now know that changesite-(Y) forms late in the late basalt crystallization phase and is relatively common in Chang’e 5 samples,” Du said.
Researchers in the United States and Europe were using data from Chang’e 5 to simulate basalt crystallization, Du said.
“I feel very fortunate to be part of this generation of Chinese scientists and to be able to study the precious lunar samples returned from my country,” Du said. “For me, it’s like witnessing history.”
Russia and China considering building nuclear power plant on the moon
Russia and China considering building nuclear power plant on the moon
“Chang’e 6 may help us understand one of the biggest mysteries: the moon’s duality: why the far side and far side of the moon are so different. We can’t wait to find out the answer.” No,” she said.
[ad_2]
Source link
