Evidence of dinosaur-killing asteroid impact found on the moon

Our work studying the impact beads from the Chang’e-5 lunar soils has been published in Science Advances on Sept. 28, 2022. We proved that there are at least 17 age groups of the impact beads from the Chang’e-5 lunar soils. They hide the secrets of the inner solar system dynamic history, including the impact killed dinosaur. Please check the related interview in Space.com here: https://www.space.com/asteroid-impact-record-lunar-glass

Scientists have new moon rocks for the first time in nearly 50 years

My research of the Chang’e-5 landing site was reported by Popular Science (https://www.popsci.com/). Here are the story: https://www.popsci.com/space/first-new-moon-rocks-in-50-years/
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The first delivery of lunar rocks and soil since the Cold War is already showing traces of intense surface conditions in the moon’s ancient past.

The Chinese National Space Administration’s Chang’e 5 lander touched down on the moon on Dec. 1, 2020. A little more than two weeks later, it brought back samples of lunar rock and regolith which it had drilled and scooped from the landing site in the Oceanus Procellarum region—a massive dark swath a few thousand kilometers wide, visible on the nearside of the moon. Within this lowland area, the landing site is one of the geologically younger regions of the moon, and the samples are the youngest ever to be returned to Earth for analysis.

Apollo 11 returned the first lunar samples to Earth in July 1969. But no mission has brought moon rocks or soil back to Earth labs since the Soviet Union’s Luna 24 mission in 1976, making Chang’e 5’s samples the first in 45 years. The mission is the fifth in the country’s moon exploration history, and is named after a goddess of the moon in Chinese mythology.

“Chang’e 5 mission is a milestone, after [the] Apollo and Luna missions, of human’s exploration of the moon,” says Yuqi Qian, a planetary geology Ph.D. student at the China University of Geosciences who was part of the team that did the preliminary analysis of the samples.

Qian announced the team’s results at the recent Europlanet Science Congress, an international planetary science conference.

[Related: The moon is (slightly) wet, NASA confirms. Now what?]

Scientists’ knowledge of the moon has changed dramatically since the previous sampling missions, Qian says, and this is the first time they’ll be able to compare their knowledge with new samples to see “whether we have a correct understanding of the moon.”

China’s space agency decides which proposed experiments will get to make use of the almost two kilograms of fresh samples. “We are so lucky because the Chang’e 5 sample application is so competitive,” Qian says.

The China University of Geosciences applied for the first batch of returned samples and acquired just 200 milligrams of Chang’e 5 cargo in July. The Chinese National Space Administration received 85 proposals and only 31 of them were approved, Qian says.

Before Chang’e 5 returned the samples, Qian tried in a previous study to judge the age of the landing site, and arrived at an estimate of 1.8 to 2.2 billion years old, based on remote sensing data. When the team obtained the samples, they found that the area was right in the middle of his estimate’s range—about 2 billion years old, Qian says, which was a big relief.

The team found that about 90 percent of the sample were mare basalts—rocks local to the lowland region—with the remaining 10 percent a mix of exotic materials from rarer sources. 

These exotic materials included “non-mare materials” like distant impact ejecta, glassy volcanic beads, remains of fallen meteorites, and silica-rich matter from lunar shield volcanoes.

This sample makeup allowed the team to guess at the history of the region using geological forensics. They found that the impact that caused the 39 kilometer wide Harpalus crater probably threw ejecta all the way to the Chang’e-5 landing site 300 kilometers away, which made up a large amount of the exotic material. Two more huge and far off craters, called Copernicus and Aristarchus, 1300 and 600 kilometers away, respectively also added a significant amount of exotic material. Though they are distant from the landing site, all three craters were caused by huge impacts that could have flung material across the moon.

[Related: Enjoy breathing oxygen? Thank the moon.]

The volcanic beads also provide a geological record of an ancient, hot moon which still harbored erupting volcanoes. These little droplets fell and cooled in the surrounding space, then rained down onto the lunar surface. The Apollo missions returned some of these beads and scientists learned in 2008 that samples of them contained ancient moon water from deep underground.

Chang’e-5’s samples were also important for determining the age of lunar features because the current aging model works well for features more than 3 billion years old or less than 1 billion years old, but isn’t as accurate for the period in between, Qian says. With these 2 billion-year-old samples, scientists will be able to better calibrate the dating model for the gap, Qian says.

The international science community’s precious trove of moon rocks will hopefully continue to grow soon, with NASA’s upcoming Artemis missions set to bring back many more lunar samples.

Leto Sapunar

Leto Sapunar

Leto is a freelance science journalist. He studied physics at Oregon State University, then got a master’s at NYU’s Science Health and Environmental Reporting Program (SHERP). You can also find his bylines at Scientific American, Inside Climate News, and Retraction Watch among other outlets. When he’s not working, he’s writing science fiction or climbing something, anything.

Exotic Mix in China’s Delivery of Moon Rocks 

My talk in Europlanet Planetary Science Congress on Sept 16, 2021, was reported by the Europlanet Society (https://www.europlanet-society.org/). Here are the story: https://www.europlanet-society.org/epsc2021-exotic-mix-in-chinas-delivery-of-moon-rocks/
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On 16 December 2020 the Chang’e-5 mission, China’s first sample return mission to the Moon, successfully delivered to Earth nearly two kilograms of rocky fragments and dust from our celestial companion.  

Chang’e-5 landed on an area of the Moon not sampled by the NASA Apollo or the Soviet Luna missions nearly 50 years ago, and thus retrieved fragments of the youngest lunar rocks ever brought back for analysis in laboratories on Earth. The rocks are also different to those returned decades ago. Early-stage findings, which use geological mapping to link ‘exotic’ fragments in the collected samples to features near the landing site, have been presented by Mr Yuqi Qian, a PhD student at the China University of Geosciences, at the Europlanet Science Congress (EPSC) 2021 virtual meeting.

The Chang’e-5 landing site is located on the western edge of the nearside of the Moon in the Northern Oceanus Procellarum. This is one of the youngest geological areas of the Moon with an age of roughly two billion years. The materials scraped from the surface comprise a loose soil that results from the fragmentation and powdering of lunar rocks over billions of years due to impacts of various sizes.  

The study presented by Qian suggests that ninety percent of the materials collected by Chang’e-5 likely derive from the landing site and its immediate surroundings, which are of a type termed ‘mare basalts’. These volcanic rocks are visible to us as the darker grey areas that spilled over much of the nearside of the Moon as ancient eruptions of lava. Yet ten percent of the fragments have distinctly different, ‘exotic’ chemical compositions, and may preserve records of other parts of the lunar surface as well as hints of the types of space rocks that have impacted the Moon’s surface. 

Qian and colleagues from Brown University and the University of Münster have looked at the potential sources of beads of rapidly cooled glassy material. They have traced these glassy droplets to now extinct volcanic vents known as ‘Rima Mairan’ and ‘Rima Sharp’ located roughly 230 and 160 kilometres southeast and northeast of the Chang’e-5 landing site. These fragments could give insights into past episodes of energetic, fountain-like volcanic activity on the Moon.

The team has also looked at the potential sources of impact-related fragments. The young geological age of the rocks at the landing site narrows the search, as only craters with ages less than 2 billion years can be responsible, and these are relatively rare on the side of the Moon that faces Earth.  The team has modelled the potential contributions from specific craters to the south and southeast (Aristarchus, Kepler, and Copernicus), northwest (Harding), and northeast (Harpalus). Qian’s findings show that Harpalus is a significant contributor of many exotic fragments among Chang’e-5’s sample haul, and these pieces of rock could offer a way to address persisting uncertainty about this crater’s age. Some fragments may have been thrown into Chang’e-5 landing area from nearly 1,300 kilometres away. 

Modelling and review of work by other teams has linked other exotic pieces of rock to domes rich in silica or to highland terranes, mountains of pale rock that surround the landing site.

“All of the local and exotic materials among the returned samples of Chang’e-5 can be used to answer a number of further scientific questions,” said Qian. “In addressing these we shall deepen our understanding of the Moon’s history and help prepare for further lunar exploration.” 

Presentation

Qian, Y., Xiao, L., Head, J., van der Bogert, C., and Hiesinger, H.: The Exotic Materials at the Chang’e-5 Landing Site, Europlanet Science Congress 2021, online, 13–24 Sep 2021, EPSC2021-447, https://doi.org/10.5194/epsc2021-447, 2021.

Images

Schematic diagram of the lunar lander of the Chang’e-5 mission. Credit: CNSA (China National Space Administration) / CLEP (China Lunar Exploration Program) / GRAS (Ground Research Application System).
Schematic diagram of the lunar lander of the Chang’e-5 mission. Credit: CNSA (China National Space Administration) / CLEP (China Lunar Exploration Program) / GRAS (Ground Research Application System).
Image showing the location of the Chang’e-5 landing site (43.06°N, 51.92°W) and adjacent regions of the Moon, as well as impact craters that were examined as possible sources of exotic fragments among the recently returned lunar materials. Credit: Qian et al. 2021
Image showing the location of the Chang’e-5 landing site (43.06°N, 51.92°W) and adjacent regions of the Moon, as well as impact craters that were examined as possible sources of exotic fragments among the recently returned lunar materials. Credit: Qian et al. 2021
Image zooming in on the location of the Chang’e-5 landing site while showing nearby impact craters that were examined as possible sources of exotic fragments among the recently returned lunar materials. Credit: Qian et al. 2021
Image zooming in on the location of the Chang’e-5 landing site while showing nearby impact craters that were examined as possible sources of exotic fragments among the recently returned lunar materials. Credit: Qian et al. 2021
Panoramic image taken after sampling of the lunar surface by Chang'e-5. The four dark trenches in the lower right corner of this image are where samples were collected. Abundant centimetre-sized boulders exist on the surface around the Chang'e-5 landing site. Credit: CNSA (China National Space Administration) / CLEP (China Lunar Exploration Program) / GRAS (Ground Research Application System).
Panoramic image taken after sampling of the lunar surface by Chang’e-5. The four dark trenches in the lower right corner of this image are where samples were collected. Abundant centimetre-sized boulders exist on the surface around the Chang’e-5 landing site. Credit: CNSA (China National Space Administration) / CLEP (China Lunar Exploration Program) / GRAS (Ground Research Application System).
Image of the Chang'e-5 sample “CE5C0400” from the Moon’s surface. This fraction of lunar materials returned to Earth by Chang’e-5 weighs nearly 35 grams and was collected by a robotic arm. Credit: CNSA (China National Space Administration) / CLEP (China Lunar Exploration Program) / GRAS (Ground Research Application System).
Image of the Chang’e-5 sample “CE5C0400” from the Moon’s surface. This fraction of lunar materials returned to Earth by Chang’e-5 weighs nearly 35 grams and was collected by a robotic arm. Credit: CNSA (China National Space Administration) / CLEP (China Lunar Exploration Program) / GRAS (Ground Research Application System).

Video

EPSC2021 Video presentation of Yuqi Qian et al. given at the Europlanet Science Congress 2021 virtual on YouTube: https://www.youtube.com/embed/QMv1qjf8kI4?feature=oembed

Further information

All sample information and data collected by the Chang’e-5 mission and China’s other planetary missions can be found at this website – https://moon.bao.ac.cn/web/enmanager/home. Additional images of studied samples can be obtained from this source.

Science contact

Yuqi Qian
PhD Candidate
Planetary Science Institute, School of Earth Sciences
China University of Geosciences (Wuhan)
388 Lumo Road, Hongshan Dist., Wuhan, 430074, China
yuqii.qian@gmail.com
@Yuqii.Qian

Media contacts

EPSC2021 Press Office
epsc-press@europlanet-society.org

About the Europlanet Science Congress (EPSC) 

The Europlanet Science Congress (https://www.epsc2021.eu/), formerly the European Planetary Science Congress, is the annual meeting place of the Europlanet Society. With a track record of 15 years, and regularly attracting around 1000 participants, EPSC is the largest planetary science meeting in Europe. It covers the entire range of planetary sciences with an extensive mix of talks, workshops and poster sessions, as well as providing a unique space for networking and exchanges of experiences.

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EPSC2021 is sponsored by Space: Science & Technology (https://spj.sciencemag.org/journals/space/ ), a Science Partner Journal.

About Europlanet

Since 2005, Europlanet (www.europlanet-society.org) has provided Europe’s planetary science community with a platform to exchange ideas and personnel, share research tools, data and facilities, define key science goals for the future, and engage stakeholders, policy makers and European citizens with planetary science. 

The Europlanet 2024 Research Infrastructure (RI) has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 871149 to provide access to state-of-the-art research facilities and a mechanism to coordinate Europe’s planetary science community. 

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