China's Chang'e-4 probe soft-lands on moon's far side - Xinhua
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Edgar Kaiser@df2mz
The Chang'e-3 lunar lander was active again this morning on 8470 MHz. The moon was not visible over China, so this activity must have been controlled by the Argentinian groundstation or one of the nice Yuanwang tracking ships wherever they are.
4:18 PM - Jul 24, 2019
The Chang'e-3 lunar lander was active again this morning on 8470 MHz. The moon was not visible over China, so this activity must have been controlled by the Argentinian groundstation or one of the nice Yuanwang tracking ships wherever they are.
4:18 PM - Jul 24, 2019
JSCh
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Chang'e-4 Lander, Yutu No. 2 lunar rover completed the wake-up setting and entered the eighth lunar day's work
China Lunar Exploration Project
Published on 2019-07-27 14:03:54
The No. 4 lander successfully completed the wake-up setting at 19:12 on July 26 and entered the eighth lunar day work period. Scientific loads such as lunar neutrons and radiation dose detectors and low-frequency radio spectrum analyzers carried by the lander will be launched one after another, and effective scientific detection work will be carried out as planned.
Previously at 3:59 on July 26, a telemetry signal was received from the Yulu No. 2 lunar rover after it has successfully awakened autonomously. The rover was equipped with panoramic camera, moon-ground penetrating radar, an infrared imaging spectrometer, and a neutral atomic detector. These instruments will be restarted for the new lunar day. After that, Yutu No. 2 will continue to carry out exploration missions in accordance with the planned routes by scientific researchers.
JSCh
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18:58, 30-Jul-2019
China's latest Moon mission costs about as much as building 1 km of subway
Updated 20:58, 30-Jul-2019
By Gong Zhe
VCG Photo with modifications
Recently, CGTN Digital received questions from readers about the cost of China's Chang'e-4 lunar mission.
So how much money did China spend on building the Chang'e-4 lunar lander, the Yutu-2 lunar rover and the rocket to send them to the far side of the Moon?
According to Wu Yanhua, deputy director of the project, the total cost of the mission was "not much."
"The cost is close to building one kilometer of subway," he said in a press conference back in January 2019.
The cost-per-kilometer of subway in China varies from 500 million yuan (about 72.6 million U.S. dollars) to 1.2 billion yuan (about 172.4 million U.S. dollars), based on the difficulty of construction.
So we still don't have the exact number, but the range is close enough to give people a solid estimation of the cost of a Moon trip.
By comparison, India's ongoing Chandrayaan-2 mission has already cost about 141 million U.S. dollars.
Is the Chang'e-4 really "reused trash?"
Wu also revealed another detail that Chang'e-4 was not designed to go to the far side of the Moon initially.
"The Chang'e-4 lunar lander was originally a backup to the previous model Chang'e-3," he said.
Since the Chang'e-3 was a success and no longer need a backup, the Chang'e-4 was "re-purposed for its current mission."
Wu didn't directly say the move saved money for China's space program, but it's obviously true since the Chang'e-4 recycled material from an already successful mission.
"The Chinese government's investment in the space program is in parallel with the country's economic situation," he concluded.
China's latest Moon mission costs about as much as building 1 km of subway
Updated 20:58, 30-Jul-2019
By Gong Zhe
Recently, CGTN Digital received questions from readers about the cost of China's Chang'e-4 lunar mission.
So how much money did China spend on building the Chang'e-4 lunar lander, the Yutu-2 lunar rover and the rocket to send them to the far side of the Moon?
According to Wu Yanhua, deputy director of the project, the total cost of the mission was "not much."
"The cost is close to building one kilometer of subway," he said in a press conference back in January 2019.
The cost-per-kilometer of subway in China varies from 500 million yuan (about 72.6 million U.S. dollars) to 1.2 billion yuan (about 172.4 million U.S. dollars), based on the difficulty of construction.
So we still don't have the exact number, but the range is close enough to give people a solid estimation of the cost of a Moon trip.
By comparison, India's ongoing Chandrayaan-2 mission has already cost about 141 million U.S. dollars.
Is the Chang'e-4 really "reused trash?"
Wu also revealed another detail that Chang'e-4 was not designed to go to the far side of the Moon initially.
"The Chang'e-4 lunar lander was originally a backup to the previous model Chang'e-3," he said.
Since the Chang'e-3 was a success and no longer need a backup, the Chang'e-4 was "re-purposed for its current mission."
Wu didn't directly say the move saved money for China's space program, but it's obviously true since the Chang'e-4 recycled material from an already successful mission.
"The Chinese government's investment in the space program is in parallel with the country's economic situation," he concluded.
JSCh
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Andrew Jones@AJ_FI
The Chang'e-4 lander & Yutu-2 rover powered down at 09:00 & 09:50 Universal Time (UT) respectively today, August 7th, ending lunar day 8 in Von Kármán crater. Yutu-2 covered ~33.13 metres during day 8 for a total mission drive distance of 271 metres. https://www.weibo.com/ttarticle/p/show?id=2309404402756415782975 …
9:03 PM - Aug 7, 2019
JSCh
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嫦娥四号着陆器和“玉兔二号”月球车顺利唤醒，进入第九月昼
The No. 4 lander and Yutu-2 lunar rover smoothly awakened and entered the ninth lunar day
中国探月工程 08-25 13:47
目前，嫦娥四号着陆器和“玉兔二号”巡视器再次通过月夜低温考验，分别于8月25日8时10分和24日8时42分自主唤醒，进入第九月昼。
At present, the No. 4 Lander and the Yutu-2 rover passed the moon and night low temperature test again, had awakened spontaneously at 8:10 on August 25 and 8:42 on the 24th, respectively, and entered the ninth lunar day.
后续，着陆器搭载载荷月表中子及辐射剂量探测仪、低频射电频谱仪，巡视器搭载载荷全景相机、测月雷达、红外成像光谱仪、中性原子探测仪等在本个月昼期间将陆续开机，继续开展科学探测任务，获取包括月表形貌、物质组成和浅表层结构等月球科学数据。“玉兔二号”也将按照科研人员规划的路线继续行驶，在指定探测点开展科学探测工作。
Subsequently, the lander equipped with a neutron and radiation dose detectors, low-frequency radio spectrum analyzers, and the rover is equipped with a panoramic camera, a lunar penetrating radar, an infrared imaging spectrometer, and a neutral atomic detector. They would be restart up, continue to carry out scientific exploration tasks, and obtain lunar scientific data including moon surface morphology, material composition and subsurface structure. Yutu-2 rover will continue to follow the route planned by the scientific research personnel, and carry out scientific exploration work at the designated detection points.
The No. 4 lander and Yutu-2 lunar rover smoothly awakened and entered the ninth lunar day
目前，嫦娥四号着陆器和“玉兔二号”巡视器再次通过月夜低温考验，分别于8月25日8时10分和24日8时42分自主唤醒，进入第九月昼。
At present, the No. 4 Lander and the Yutu-2 rover passed the moon and night low temperature test again, had awakened spontaneously at 8:10 on August 25 and 8:42 on the 24th, respectively, and entered the ninth lunar day.
后续，着陆器搭载载荷月表中子及辐射剂量探测仪、低频射电频谱仪，巡视器搭载载荷全景相机、测月雷达、红外成像光谱仪、中性原子探测仪等在本个月昼期间将陆续开机，继续开展科学探测任务，获取包括月表形貌、物质组成和浅表层结构等月球科学数据。“玉兔二号”也将按照科研人员规划的路线继续行驶，在指定探测点开展科学探测工作。
Subsequently, the lander equipped with a neutron and radiation dose detectors, low-frequency radio spectrum analyzers, and the rover is equipped with a panoramic camera, a lunar penetrating radar, an infrared imaging spectrometer, and a neutral atomic detector. They would be restart up, continue to carry out scientific exploration tasks, and obtain lunar scientific data including moon surface morphology, material composition and subsurface structure. Yutu-2 rover will continue to follow the route planned by the scientific research personnel, and carry out scientific exploration work at the designated detection points.
JSCh
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China's Lunar Rover Has Found Something Weird on the Far Side of the Moon
By Andrew Jones 3 days ago Spaceflight
Tracks made by Yutu-2 while navigating hazards during lunar day 8, which occurred during late July and early August 2019.
(Image: © China Lunar Exploration Project)
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.
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.
Yutu-2 found a strangely-colored substance in a crater on the far side of the moon.(Image credit: China Lunar Exploration Project)
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.
Tracks showing Yutu-2's approach to the crater for analysis of the gel-like substance.(Image credit: China Lunar Exploration Project)
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.
Strange orange soil was discovered on the moon by the Apollo 17 mission in 1972.(Image credit: Apollo 17 Crew/NASA)
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.
A stitched image from Yutu-2 looking back toward the Chang'e-4 lander during lunar day 7, in late June and early July 2019.(Image credit: China Lunar Exploration Project)
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.
https://www.space.com/china-far-side-moon-rover-strange-substance.html
By Andrew Jones 3 days ago Spaceflight
(Image: © China Lunar Exploration Project)
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.
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.
https://www.space.com/china-far-side-moon-rover-strange-substance.html
JSCh
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China's lunar rover travels over 284 meters on moon's far side
Source: Xinhua| 2019-09-07 08:57:02|Editor: mingmei
BEIJING, Sept. 7 (Xinhua) -- China's lunar rover Yutu-2 has driven 284.66 meters on the far side of the moon to conduct scientific exploration on the virgin territory.
Both the lander and the rover of the Chang'e-4 probe switched to its dormant mode for the lunar night on Friday (Beijing time), according to the Lunar Exploration and Space Program Center of the China National Space Administration.
China's Chang'e-4 probe, launched on Dec. 8, 2018, made the first-ever soft landing on the Von Karman Crater in the South Pole-Aitken Basin on the far side of the moon on Jan. 3.
A lunar day equals 14 days on Earth, a lunar night the same length. The Chang'e-4 probe switches to dormant mode during the lunar night due to lack of solar power.
During the ninth lunar day of the probe on the moon, the scientific instruments on the lander and rover worked well, and a new batch of 2.9 GB scientific detection data was sent to the core research team for analysis.
As a result of the tidal locking effect, the moon's revolution cycle is the same as its rotation cycle, and the same side always faces Earth.
The far side of the moon has unique features, and scientists expect Chang'e-4 could bring breakthrough findings.
The scientific tasks of the Chang'e-4 mission include low-frequency radio astronomical observation, surveying the terrain and landforms, detecting the mineral composition and shallow lunar surface structure and measuring neutron radiation and neutral atoms.
The Chang'e-4 mission embodies China's hope to combine wisdom in space exploration with four payloads developed by the Netherlands, Germany, Sweden and Saudi Arabia.
Source: Xinhua| 2019-09-07 08:57:02|Editor: mingmei
BEIJING, Sept. 7 (Xinhua) -- China's lunar rover Yutu-2 has driven 284.66 meters on the far side of the moon to conduct scientific exploration on the virgin territory.
Both the lander and the rover of the Chang'e-4 probe switched to its dormant mode for the lunar night on Friday (Beijing time), according to the Lunar Exploration and Space Program Center of the China National Space Administration.
China's Chang'e-4 probe, launched on Dec. 8, 2018, made the first-ever soft landing on the Von Karman Crater in the South Pole-Aitken Basin on the far side of the moon on Jan. 3.
A lunar day equals 14 days on Earth, a lunar night the same length. The Chang'e-4 probe switches to dormant mode during the lunar night due to lack of solar power.
During the ninth lunar day of the probe on the moon, the scientific instruments on the lander and rover worked well, and a new batch of 2.9 GB scientific detection data was sent to the core research team for analysis.
As a result of the tidal locking effect, the moon's revolution cycle is the same as its rotation cycle, and the same side always faces Earth.
The far side of the moon has unique features, and scientists expect Chang'e-4 could bring breakthrough findings.
The scientific tasks of the Chang'e-4 mission include low-frequency radio astronomical observation, surveying the terrain and landforms, detecting the mineral composition and shallow lunar surface structure and measuring neutron radiation and neutral atoms.
The Chang'e-4 mission embodies China's hope to combine wisdom in space exploration with four payloads developed by the Netherlands, Germany, Sweden and Saudi Arabia.
Galactic Penguin SST
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That 5th February 2019 map of the NASA is obsolete now. Here an update, with Yutu-2 and ISRO's Pragyan.
https://archive.is/mFGRt/db936a7ffc994e63142e26b4715b0d9e87bbe928.jpg ; https://archive.is/mFGRt/354dc9dd1e07e1624fe6bd861d3222b5214b384e/scr.png ; http://web.archive.org/web/20190908190820/https://i.imgur.com//1Q4CiAO.jpg
▲ 1. Driving distance on Mars and the Moon. As of September 2019.
JSCh
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This road map in front of you is the route that Yutu No. 2 traverse on the back of the moon. Each of the above circles represents a pit on the surface of the moon. It can be seen that the landing point of the Change'e 4 is almost surrounded by large and small pits. This means that the Yutu No. 2 encounters no small challenge right from the beginning...
JSCh
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China's lunar rover discovers mysterious substance on moon's far side
Source: Xinhua| 2019-09-24 14:37:24|Editor: mingmei
BEIJING, Sept. 24 (Xinhua) -- China's lunar rover Yutu-2, or Jade Rabbit-2, discovered an unidentified substance in an impact crater on the far side of the moon.
The discovery was made during Yutu-2's ninth lunar day of exploration on the moon, according to the Lunar Exploration and Space Program Center of the China National Space Administration.
The ground controllers designed a driving route for the rover to allow it to conduct scientific detection to the depth of the impact crater and the distribution of the ejecta, said the center.
"The Yutu-2 rover is expected to bring us more surprises and scientific discoveries," said the center.
The lander of the Chang'e-4 probe and the Yutu-2 rover have resumed work for the 10th lunar day on the far side of the moon after "sleeping" during the extremely cold lunar night.
The lander woke up at 8:26 p.m. Monday, and the rover awoke at 8:30 p.m. Sunday (Beijing Time). Both are in normal working condition, according to the center.
The rover has traveled about 285 meters on the moon to conduct scientific exploration on the virgin territory.
China's Chang'e-4 probe, launched on Dec. 8, 2018, made the first-ever soft landing on the Von Karman Crater in the South Pole-Aitken Basin on the far side of the moon on Jan. 3.
A lunar day equals 14 days on Earth, and a lunar night is the same length. The Chang'e-4 probe switched to a dormant mode during the lunar night due to the lack of solar power.
As a result of the tidal locking effect, the moon's revolution cycle is the same as its rotation cycle, and the same side always faces Earth.
The scientific tasks of the Chang'e-4 mission include low-frequency radio astronomical observation, surveying the terrain and landforms, detecting the mineral composition and shallow lunar surface structure and measuring neutron radiation and neutral atoms.
The Chang'e-4 mission embodies China's hope to combine human wisdom in space exploration with four payloads developed by the Netherlands, Germany, Sweden and Saudi Arabia.
Source: Xinhua| 2019-09-24 14:37:24|Editor: mingmei
BEIJING, Sept. 24 (Xinhua) -- China's lunar rover Yutu-2, or Jade Rabbit-2, discovered an unidentified substance in an impact crater on the far side of the moon.
The discovery was made during Yutu-2's ninth lunar day of exploration on the moon, according to the Lunar Exploration and Space Program Center of the China National Space Administration.
The ground controllers designed a driving route for the rover to allow it to conduct scientific detection to the depth of the impact crater and the distribution of the ejecta, said the center.
"The Yutu-2 rover is expected to bring us more surprises and scientific discoveries," said the center.
The lander of the Chang'e-4 probe and the Yutu-2 rover have resumed work for the 10th lunar day on the far side of the moon after "sleeping" during the extremely cold lunar night.
The lander woke up at 8:26 p.m. Monday, and the rover awoke at 8:30 p.m. Sunday (Beijing Time). Both are in normal working condition, according to the center.
The rover has traveled about 285 meters on the moon to conduct scientific exploration on the virgin territory.
China's Chang'e-4 probe, launched on Dec. 8, 2018, made the first-ever soft landing on the Von Karman Crater in the South Pole-Aitken Basin on the far side of the moon on Jan. 3.
A lunar day equals 14 days on Earth, and a lunar night is the same length. The Chang'e-4 probe switched to a dormant mode during the lunar night due to the lack of solar power.
As a result of the tidal locking effect, the moon's revolution cycle is the same as its rotation cycle, and the same side always faces Earth.
The scientific tasks of the Chang'e-4 mission include low-frequency radio astronomical observation, surveying the terrain and landforms, detecting the mineral composition and shallow lunar surface structure and measuring neutron radiation and neutral atoms.
The Chang'e-4 mission embodies China's hope to combine human wisdom in space exploration with four payloads developed by the Netherlands, Germany, Sweden and Saudi Arabia.
JSCh
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23 SEPTEMBER 2019
New study complicates theory that ancient impact pierced Moon’s crust - GeoSpace - AGU Blogosphere
Posted by larryohanlon
By Abigail Eisenstadt
The moon’s largest and oldest impact crater likely doesn’t have minerals from below the lunar crust on its surface, complicating a theory that an ancient massive impact event pierced the Moon’s crust during the crater’s formation, a new study finds.
A study published earlier this year analyzed the way lunar materials reflect light to determine that a basin-forming impact that formed an ancient massive crater, the South Pole-Aitken basin, caused minerals from deep inside the Moon’s mantle to rupture the Moon’s surface. If mantle materials breached the lunar crust, studying them could yield significant clues about the Moon’s history.
Now, new research in the AGU journal Geophysical Research Letters reexamined the same data, acquired by the Chinese spacecraft Chang’E 4’s rover, which landed in the crater in January 2019. The new study finds the crater’s crust mainly consists of a common lunar crustal mineral not detected in earlier analyses. The new results suggest the basin floor may not have exposed lunar mantle material as previously reported.
This image of the Moon was taken by the International Space Station. Sometimes the far side of the Moon is called the “dark side,” but in reality both sides of the Moon have two weeks of sunlight followed by two weeks of darkness. Chang’E 4 landed on the far side of the Moon that never faces Earth. Credit: Fernando Echeverria
“We are not seeing the mantle materials at the landing site as expected,” said Hao Zhang, a planetary scientist at the China University of Geosciences, Wuhan, China, and a co-author of the new study.
The new study complicates theories about how the oldest, largest crater on Moon formed, adding to the body of knowledge about the Moon’s history.
Dating the South Pole-Aitken basin
Images show wrinkles in the Aitken Crater.
Credit: NASA/GSFC/Arizona State University
The South Pole-Aitken basin is considered one of the largest craters in the Solar System and the oldest on the Moon. The basin is 2,500 kilometers (1,553 miles) in diameter and runs roughly 13 kilometers (8 miles) deep. The basin resides on the Moon’s far side, the enigmatic area facing away from Earth. It was untouched until Chang’E 4’s landing in the crater in January 2019.
Although scientists haven’t radiometrically dated the basin’s age yet, some estimates place its formation at 4.2 billion years ago.
Scientists theorized the South Pole-Aitken basin-forming event ruptured the lunar crust, because of how deep the basin is today. Crustal topographic maps estimate the crust only extends 30 kilometers (19 miles) beneath the crater, whereas the rest of the lunar crust is 40 kilometers (25 miles) thick on average.
The Moon was once covered in molten magma oceans. Over time, these cooled and separated into crust and mantle layers distinguished by many characteristics, including their mineral composition. Clinopyroxene, orthopyroxene, and olivine are all minerals associated with the Moon’s mantle. They occasionally appear on the surface of the Moon, but large concentrations of them in a region could signal that the mantle once punctured the crust.
Testing the crustal composition
Spectroscopy is the study of how matter interacts with light. Minerals absorb specific wavelengths of light and color, which gives them unique signatures. Astrophysicists perform different types of spectroscopy to determine the composition and concentration of different materials on planetary bodies and their regions, based on these unique signatures.
Previous research published in May in the journal Nature found concentrations of clinopyroxene, orthopyroxene, and olivine in the crater – amounts high enough to seemingly confirm the theory that the mantle had once breached the crust. The Nature study analyzed spectroscopic soil data from Chang’E 4 and processed the data using a series of functions. This process allowed them to identify the mathematically best fitting mineral for each’s spectra compositions.
Zhang and his colleagues also analyzed spectroscopic data acquired by instruments on Chang’E 4’s rover after the spacecraft landed in the crater. They used a technique that compared the rover’s documented reflections of light and color from the lunar surface to a database of known minerals. The database accounted for minerals’ particle size, the way the minerals interact with light, and how they respond to space weathering – changes to the soil surface caused by solar wind irradiation and bombardment from tiny particles that the Moon’s surface experiences.
This different process allowed the researchers to detect and measure the amount of plagioclase in the crater. Plagioclase is a mineral created from cooling lava. It’s also one of the most common rocks on the Moon’s surface. The results showed plagioclase made up 56-72% of the crater’s composition, making it the majority mineral. The high concentration of plagioclase suggests the lunar crust was not pierced by an ancient impact.
The new study also found the landing site on the crater had concentrations of 9-28% orthopyroxene, 4-19% clinopyroxene, and 2-12% olivine. Although The three minerals are in the basin, they are not present at high enough amounts to prove an impact event once broke the crust, according to the study’s authors.
The new study complicates the certainty of earlier findings and points towards a need for continued research on the far side’s lunar surface, according to Zhang.
Abigail Eisenstadt is a science writing intern at AGU. Follow her on twitter @aeisenstadt1
New study complicates theory that ancient impact pierced Moon’s crust - GeoSpace - AGU Blogosphere
Posted by larryohanlon
By Abigail Eisenstadt
The moon’s largest and oldest impact crater likely doesn’t have minerals from below the lunar crust on its surface, complicating a theory that an ancient massive impact event pierced the Moon’s crust during the crater’s formation, a new study finds.
A study published earlier this year analyzed the way lunar materials reflect light to determine that a basin-forming impact that formed an ancient massive crater, the South Pole-Aitken basin, caused minerals from deep inside the Moon’s mantle to rupture the Moon’s surface. If mantle materials breached the lunar crust, studying them could yield significant clues about the Moon’s history.
Now, new research in the AGU journal Geophysical Research Letters reexamined the same data, acquired by the Chinese spacecraft Chang’E 4’s rover, which landed in the crater in January 2019. The new study finds the crater’s crust mainly consists of a common lunar crustal mineral not detected in earlier analyses. The new results suggest the basin floor may not have exposed lunar mantle material as previously reported.
“We are not seeing the mantle materials at the landing site as expected,” said Hao Zhang, a planetary scientist at the China University of Geosciences, Wuhan, China, and a co-author of the new study.
The new study complicates theories about how the oldest, largest crater on Moon formed, adding to the body of knowledge about the Moon’s history.
Dating the South Pole-Aitken basin
Credit: NASA/GSFC/Arizona State University
The South Pole-Aitken basin is considered one of the largest craters in the Solar System and the oldest on the Moon. The basin is 2,500 kilometers (1,553 miles) in diameter and runs roughly 13 kilometers (8 miles) deep. The basin resides on the Moon’s far side, the enigmatic area facing away from Earth. It was untouched until Chang’E 4’s landing in the crater in January 2019.
Although scientists haven’t radiometrically dated the basin’s age yet, some estimates place its formation at 4.2 billion years ago.
Scientists theorized the South Pole-Aitken basin-forming event ruptured the lunar crust, because of how deep the basin is today. Crustal topographic maps estimate the crust only extends 30 kilometers (19 miles) beneath the crater, whereas the rest of the lunar crust is 40 kilometers (25 miles) thick on average.
The Moon was once covered in molten magma oceans. Over time, these cooled and separated into crust and mantle layers distinguished by many characteristics, including their mineral composition. Clinopyroxene, orthopyroxene, and olivine are all minerals associated with the Moon’s mantle. They occasionally appear on the surface of the Moon, but large concentrations of them in a region could signal that the mantle once punctured the crust.
Testing the crustal composition
Spectroscopy is the study of how matter interacts with light. Minerals absorb specific wavelengths of light and color, which gives them unique signatures. Astrophysicists perform different types of spectroscopy to determine the composition and concentration of different materials on planetary bodies and their regions, based on these unique signatures.
Previous research published in May in the journal Nature found concentrations of clinopyroxene, orthopyroxene, and olivine in the crater – amounts high enough to seemingly confirm the theory that the mantle had once breached the crust. The Nature study analyzed spectroscopic soil data from Chang’E 4 and processed the data using a series of functions. This process allowed them to identify the mathematically best fitting mineral for each’s spectra compositions.
Zhang and his colleagues also analyzed spectroscopic data acquired by instruments on Chang’E 4’s rover after the spacecraft landed in the crater. They used a technique that compared the rover’s documented reflections of light and color from the lunar surface to a database of known minerals. The database accounted for minerals’ particle size, the way the minerals interact with light, and how they respond to space weathering – changes to the soil surface caused by solar wind irradiation and bombardment from tiny particles that the Moon’s surface experiences.
This different process allowed the researchers to detect and measure the amount of plagioclase in the crater. Plagioclase is a mineral created from cooling lava. It’s also one of the most common rocks on the Moon’s surface. The results showed plagioclase made up 56-72% of the crater’s composition, making it the majority mineral. The high concentration of plagioclase suggests the lunar crust was not pierced by an ancient impact.
The new study also found the landing site on the crater had concentrations of 9-28% orthopyroxene, 4-19% clinopyroxene, and 2-12% olivine. Although The three minerals are in the basin, they are not present at high enough amounts to prove an impact event once broke the crust, according to the study’s authors.
The new study complicates the certainty of earlier findings and points towards a need for continued research on the far side’s lunar surface, according to Zhang.
Abigail Eisenstadt is a science writing intern at AGU. Follow her on twitter @aeisenstadt1
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