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We know that the Chandrayaan-3 mission found the presence of sulphur on the surface of the moon.

How did it come up to the surface of the moon if this element is supposed to be in the moon's core rather than the surface?

Why weren't other missions like Luna, Apollo, etc able to detect it?

How will this discovery influence future research of the moon?

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    $\begingroup$ Sulfur on the Moon is nothing new. It was detected in soil samples collected during the American Apollo program. The recent discovery of sulfur near the lunar south pole suggests it is more widespread on the surface of the Moon. $\endgroup$
    – Fred
    Commented Aug 31, 2023 at 10:25
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    $\begingroup$ "This element was supposed to be in core region" -- what makes you think that? Sulfur is light compared to iron and nickel, and it readily forms rather light compounds. $\endgroup$ Commented Aug 31, 2023 at 11:02
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    $\begingroup$ Sulphur is not siderophilic, it's chalcophilic - it generally forms compounds that are intermediate in density between the heavy siderophiles (including iron itself, nickel) and the light lithophiles. So no, not really the core, though the crust is also relatively depleted - you find most of it in the mantle, where it's quite readily uplifted. It's thought that sulphur is present on Earth in heavily depleted numbers compared to stellar abundances, because with abundant water, it formed volatile compounds and escaped into space in huge quantities. $\endgroup$
    – Luaan
    Commented Sep 1, 2023 at 5:39
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    $\begingroup$ Moon has less gravity and way less prolonged period of being molten (compared to Earth), so one could expect less strong stratification and less separation of heavy vs lightweigth substances. Moon has prominent "mascons" supporting my consideration. $\endgroup$
    – fraxinus
    Commented Sep 1, 2023 at 11:33

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Sulfur on the Moon's surface may have come from volcanic activity, and it was found in Apollo rock samples in 2020 a few years before Chandrayaan-3 arrived.

While most of this volcanic activity took place 3 billion or more years ago, it may have continued at a low level into recent times. From Wikipedia:

In 2014, NASA announced "widespread evidence of young lunar volcanism" at 70 irregular mare patches identified by the Lunar Reconnaissance Orbiter, some less than 50 million years old. This raises the possibility of a much warmer lunar mantle than previously estimated, at least on the near side where the deep crust is substantially warmer because of the greater concentration of radioactive elements.[1][2][3][4] Just prior to this, evidence has been presented for 2–10 million years younger basaltic volcanism inside the crater Lowell,[5][6] located in the transition zone between the near and far sides of the Moon.

Volcanic sulfur would be expected to exist in a reduced state in magmas, as is evident from the sulfurous materials on the surface of Io (where atmospheric oxygen can't oxidize it as occurs on Earth). In the case of the Moon, even before the Chandrayaan-3 findings reduced sulfur was identified in the solidified basalt of Apollo 11 and Apollo 16 samples[7]. The most common metals in mafic rock (iron, calcium, magnesium) are good sulfide formers, so sulfur could naturally be expected in basaltic rock. Significant concentrations of lunar basaltic sulfur are found in apatite grains where, unlike on Earth, the sulfur is in the form of sulfide instead of sulfate.

References

  1. Jason Major (14 October 2014). "Volcanoes Erupted 'Recently' on the Moon". Discovery News. Archived from the original on 16 October 2014.

  2. "NASA Mission Finds Widespread Evidence of Young Lunar Volcanism". NASA. 12 October 2014. Archived from the original on 3 January 2015.

  3. Eric Hand (12 October 2014). "Recent volcanic eruptions on the moon". Science. Archived from the original on 14 October 2014.

  4. Braden, S.E.; Stopar, J.D.; Robinson, M.S.; Lawrence, S.J.; van der Bogert, C.H.; Hiesinger, H. (2014). "Evidence for basaltic volcanism on the Moon within the past 100 million years". Nature Geoscience. 7 (11): 787–791. Bibcode:2014NatGe...7..787B. doi:10.1038/ngeo2252.

  5. Srivastava, N.; Gupta, R.P. (2013). "Young viscous flows in the Lowell crater of Orientale basin, Moon: Impact melts or volcanic eruptions?". Planetary and Space Science. 87: 37–45. Bibcode:2013P&SS...87...37S. doi:10.1016/j.pss.2013.09.001.

  6. Gupta, R.P.; Srivastava, N.; Tiwari, R.K. (2014). "Evidences of relatively new volcanic flows on the Moon". Current Science. 107 (3): 454–460.

  7. Maryjo Brounce, Jeremy W. Boyce, Jessica Barnes, and Francis McCubbin (2020). "Sulfur in the Apollo Lunar Basalts and Implications for Future Samole-Return Missions", Elements 16 (5), 361-2.

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The moon's composition is largely similar to the earth's crust, the earth's crust contains plenty of sulphur and sulphur compounds too.

My guess on other missions is they either weren't looking for it or they simply didn't find it significant so didn't report it.

I assume you're referring to headlines like this https://twitter.com/TimesAlgebraIND/status/1696562334578442737 ?

This paper from 1992 https://space.nss.org/wp-content/uploads/Lunar-Bases-conference-2-509-Uses-Of-Lunar-Sulfur.pdf talks about sulphur being relatively abundant in lunar rocks:

Although sulfur is not so abundant that it is available without effort, it does rank eleventh in weight abundance among the elements in average lunar mare rocks

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  • $\begingroup$ Earth have its sulphur presence mostly because of its volcanic activity right? If yes, considering moon has no longer volcanos - not much sulphur production! $\endgroup$
    – Amal
    Commented Aug 31, 2023 at 9:41
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    $\begingroup$ @Amal: The Moon is not as dynamic as the Earth: no atmosphere, surface water or life. Sulfur that reached the surface of the Moon millions of years didn't reach with anything & hence remains in place. $\endgroup$
    – Fred
    Commented Aug 31, 2023 at 10:23
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    $\begingroup$ @Amal elemental sulphur, yes, is only naturally found around volcanic activity en.wikipedia.org/wiki/Sulfur but sulphur compounds are much more common, in fact there's about 140 grams of it sitting on your chair med.libretexts.org/Bookshelves/Nutrition/…. I'm pretty sure ISRO hasn't found elemental sulphur on the moon, it'll be minerals containing sulphur $\endgroup$ Commented Aug 31, 2023 at 11:37
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    $\begingroup$ @AlanBirtles That info would be really useful in the post! :) $\endgroup$ Commented Sep 1, 2023 at 17:16

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