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posted by janrinok on Thursday October 14 2021, @12:43PM   Printer-friendly

China's lunar rock samples show lava flowed on the moon 2 billion years ago:

Lava oozed across the moon's surface just 2 billion years ago, bits of lunar rocks retrieved by China's Chang'e-5 mission reveal.

A chemical analysis of the volcanic rocks confirms that the moon remained volcanically active far longer that its size would suggest possible, researchers report online October 7 in Science.

Chang'e-5 is the first mission to retrieve lunar rocks and return them to Earth in over 40 years (SN: 12/1/20). An international group of researchers found that the rocks formed 2 billion years ago, around when multicellular life first evolved on Earth. That makes them the youngest moon rocks ever collected, says study coauthor Carolyn Crow, a planetary scientist at the University of Colorado Boulder.

The moon formed roughly 4.5 billion years ago. Lunar rocks from the Apollo and Soviet missions of the late 1960s and 70s revealed that volcanism on the moon was commonplace for the first billion or so years of its existence, with flows lasting for millions, if not hundreds of millions, of years.

Given its size, scientist thought that the moon started cooling off around 3 billion years ago, eventually becoming the quiet, inactive neighbor it is today. Yet a dearth of craters in some regions left scientists scratching their heads. Parts of celestial bodies devoid of volcanism accumulate more and more craters over time, in part because there aren't lava flows depositing new material that hardens into smooth stretches. The moon's smoother spots seemed to suggest that volcanism had persisted past the moon's early history.

"Young volcanism on a small body like the moon is challenging to explain, because usually small bodies cool fast," says Juliane Gross, a planetary scientist at Rutgers University in Piscataway, N.J., not involved in the study.

Scientist had suggested that radioactive elements might offer an explanation for later volcanism. Radioactive decay generates a lot of heat, which is why nuclear reactors are kept in water. Enough radioactive materials in the moon's mantle, the layer just below the visible crust, would have provided a heat source that could explain younger lava flows.

Journal Reference:
Xiaochao Che, Alexander Nemchin, Dunyi Liu, et al. Age and composition of young basalts on the Moon, measured from samples returned by Chang’e-5, Science (DOI: https://www.science.org/doi/10.1126/science.abl7957)


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  • (Score: 1, Troll) by Rosco P. Coltrane on Thursday October 14 2021, @01:17PM (6 children)

    by Rosco P. Coltrane (4757) on Thursday October 14 2021, @01:17PM (#1186958)

    I know the science is great, and I know it's quite a technical feat. But sadly anything the Chinese do on the moon all feels a bit me-too. Such debauchery of technical means to find out lava flowed on the moon 2 BILLION years ago - and scientists going all uuh-aah over "young" volcanism. I mean gee, say what you will, it's boring as shit. I know I should, but I'm really struggling to care.

    On the bright side, I believe those me-too baby steps with boring science thrown in are all in preparation for new and genuinely exciting manned lunar missions.

    • (Score: 4, Insightful) by DannyB on Thursday October 14 2021, @01:58PM (2 children)

      by DannyB (5839) Subscriber Badge on Thursday October 14 2021, @01:58PM (#1186967) Journal

      sadly anything the Chinese do on the moon all feels a bit me-too.

      One thing China is fantastic at doing is "me too". And I mean that sincerely. They not only do "me too", but they do it faster and cheaper.

      --
      People today are educated enough to repeat what they are taught but not to question what they are taught.
      • (Score: 2) by hendrikboom on Thursday October 14 2021, @04:34PM (1 child)

        by hendrikboom (1125) Subscriber Badge on Thursday October 14 2021, @04:34PM (#1187011) Homepage Journal

        It does cost less to do something the second time.
        It costs more if you specify you'll pay cost-plus in the contract.

        • (Score: 3, Informative) by DannyB on Thursday October 14 2021, @05:29PM

          by DannyB (5839) Subscriber Badge on Thursday October 14 2021, @05:29PM (#1187031) Journal

          It certainly costs less if you don't have to do all of the original R&D. Even if SpaceX keeps some things secret, those secrets may be fairly easy to deduce.

          SpaceX has already demonstrated a lot of what "not to do", and "what to do". For example, grid fins to steer the rocket to the landing pad. At the last moments before landing Blue Origin's New Shepard seems to use a lot of engine power to guide the rocket to the pad and then set it down gently. SpaceX Falcon 9 seems to light the engine at the right moment and just run out of fuel and have no velocity as the rocket touches the pad.

          Another lesson from SpaceX. Maybe having lots of engines on a F9 isn't as big a reliability problem as people thought. And they are reusable!

          Reusability isn't an item you just bolt on after the fact. It needs to be considered in every part of the initial design. From engines to seat belts.

          One way to learn a lot of things without doing R&D is to have spies. Just how big are the two sub critical mass pieces? What velocity should they impact? What's the best way to compress plutonium? Etc.

          --
          People today are educated enough to repeat what they are taught but not to question what they are taught.
    • (Score: 1, Touché) by Anonymous Coward on Thursday October 14 2021, @02:08PM

      by Anonymous Coward on Thursday October 14 2021, @02:08PM (#1186971)

      new and genuinely exciting manned lunar missions.

      The world was enraptured by Apollo 11. By Apollo 14, nobody cared.

      That's what we need. We need space exploration to become so cheap and routine that only the explorers themselves, children, and turbo-nerds are excited by it.

    • (Score: 0) by Anonymous Coward on Thursday October 14 2021, @02:54PM (1 child)

      by Anonymous Coward on Thursday October 14 2021, @02:54PM (#1186982)

      I mean gee, say what you will

      I will say, no, it is not "boring as shit." I fear for science as we slide in the direction of determining our long term research roadmaps based on things like Facebook polls. My only hope is that groups such as the National Academies can hold back that dam until we as a society have moved on from social media "likes" and other measures of popularity on to whatever the next paradigm becomes, or until the societal pendulum swings back to another age of valuing knowledge.

  • (Score: 1, Offtopic) by DannyB on Thursday October 14 2021, @02:00PM

    by DannyB (5839) Subscriber Badge on Thursday October 14 2021, @02:00PM (#1186968) Journal

    Just because lava may have oozed across the lunar surface does not mean that it contained any life or microorganisms.

    --
    People today are educated enough to repeat what they are taught but not to question what they are taught.
  • (Score: 0) by Anonymous Coward on Thursday October 14 2021, @03:06PM (1 child)

    by Anonymous Coward on Thursday October 14 2021, @03:06PM (#1186984)

    Would they be able to tell the difference between melted rock from a volcano and melted rock from a large meteor? Maybe they landed near an asteroid strike that occurred 2 billion years ago.

    • (Score: 0) by Anonymous Coward on Thursday October 14 2021, @05:16PM

      by Anonymous Coward on Thursday October 14 2021, @05:16PM (#1187023)

      IANAAD, but I would expect lava rock formed from relatively slow moving lava would have different structures comoared to rocks formed by a flash explosion.

  • (Score: 0) by Anonymous Coward on Thursday October 14 2021, @03:07PM

    by Anonymous Coward on Thursday October 14 2021, @03:07PM (#1186985)

    The abstract:

    Orbital data indicate that the youngest volcanic units on the Moon are basalt lavas in Oceanus Procellarum, a region with high levels of the heat-producing elements potassium, thorium, and uranium. The Chang’e-5 mission collected samples of these young lunar basalts and returned them to Earth for laboratory analysis. We measure an age of 1963 ± 57 Ma for these lavas and determine their chemical and mineralogical compositions. This age constrains the lunar impact chronology of the inner Solar System and the thermal evolution of the Moon. There is no evidence for high concentrations of heat-producing elements in the deep mantle of the Moon that generated these lavas, so alternate explanations are required for the longevity of lunar magmatism.

    And here is some background for the implications of these measurements:

    The number of impact craters on a surface reflects its relative age, with older surfaces having more craters. The Moon is the only planetary body where impact crater ages have been calibrated with radiometric dating, so the lunar chronology is used to infer the ages of other planetary surfaces throughout the Solar System. For example, the climatic evolution of Mars is related directly to the lunar cratering chronology. However, the lunar chronology is highly uncertain for ages younger than ~3 Ga.

    Young volcanism on a small body such as the Moon is challenging to explain in its thermal evolution. Although the young basaltic eruptions on the Moon occurred in regions of elevated heat-producing elements such as K, Th, and U, it is unclear whether this association is responsible for melting the source magma deep within the Moon.

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