Episode Transcript
[00:00:00] China's Chang' E5 lunar probe has returned evidence indicating that volcanic eruptions occurred on the Moon as recently as 120 million years ago. Volcanic activity on the Moon has persisted in the geologically recent past, and the Moon may still be volcanically active today, based on tiny glass beads found in lunar dust brought back to earth by China's Chang' e 5 probe in December 2020. The new findings from Chang' e 5 were published on September 5th in the journal Science.
[00:00:30] Previous research had shown the moon experienced volcanic activity, with the last eruptions dated between 3 to 3.8 billion years ago.
[00:00:39] However, samples collected by Chang' E5 have provided evidence that volcanic eruptions occurred much more recently, just 123 million years ago, with a margin of error of 15 million years.
[00:00:53] This suggests that the Moon could have experienced volcanic eruptions throughout its lifetime and may still be volcanically active today.
[00:01:01] A team led by Bi Wen Wang and Qianzhang from the Institute of Geology and Geophysics at the Chinese Academy of Sciences in Beijing analyzed 1.7 grams of lunar dust collected by Chang' e 5.
[00:01:15] Among the 3,000 tiny glass beads, ranging from 20 to 400 microns in size, were signs that they were formed by the intense impact of an asteroid, which melted and compressed the rock into glass.
[00:01:29] Magma channels that produce volcanic glass have been found in previous lunar surface samples, wrote Wang and Zhang's team in the research paper. While volcanic glass particles have been found on the Moon before, they always originated from eruptions billions of years ago. From the Chang' e 5 landing site near the Mons Rumker volcanic region in Oceanus Procellarum, the probe discovered three particularly significant glass beads, which were returned to Earth on December 16, 2020.
[00:02:00] Uranium LED dating of these three volcanic glass beads indicates they were formed around 123 million years ago with an error margin of 15 million years, the researchers noted. This isn't the first evidence of geologically recent volcanic activity on the moon. In 2014, NASA's Lunar Reconnaissance Orbiter photographed approximately 70 unusual features on the lunar surface called irregular mare patches.
[00:02:29] Imps.
[00:02:31] Imps are smooth, round, shallow mounds located next to rugged, rocky terrain along slopes. The first IMP was actually photographed by NASA's Apollo 15 astronauts from lunar orbit in 1971, but it wasn't recognized at the time. While the IMPS suggested the possibility of recent volcanic activity, the glass beads provide undeniable evidence.
[00:02:56] However, models of the moon's thermal evolution suggest that the lunar interior isn't warm enough enough to produce volcanic eruptions.
[00:03:04] Contrary to this, Wang and Zhang's team measured an abundance of rare earth elements and thorium in the volcanic glass beads. This could indicate that recent volcanic activity is related to localized enrichment of heat producing elements in the mantle sources of magma, they wrote. These elements, such as potassium, phosphorus, yttrium and lanthanum can generate heat from radioactive decay, potentially melting rock in the moon's mantle and fueling small scale erupt.
