WASHINGTON, Oct 8 (WAM/APP/DNA):A team of scientists from Brown University has discovered new sulphur isotopes unlike any found on Earth, providing fresh insight into the early formation of the Moon.
The researchers analysed lunar samples that had remained sealed since they were collected by Apollo 17 astronauts in 1972. Using advanced analytical techniques, they identified an exotic form of sulphur that may offer new clues about the Moon’s origins.
NASA’s Apollo 17 mission in 1972 marked the final manned landing on the Moon. Upon returning to Earth, the crew sealed and preserved part of the material collected from the lunar surface under the Apollo Next Generation Sample Analysis (ANGSA) programme, allowing future scientists to study the samples using advanced technologies unavailable at the time.
The Brown University team has now fulfilled that mission. In a study published in the journal JGR: Planets, the researchers reported the discovery of a unique sulphur isotope in samples taken from the Moon’s Taurus-Littrow region. Their analysis revealed that volcanic material within the samples contains sulphur compounds significantly depleted in sulphur-33 (³³S), one of the four stable isotopes of sulphur. These isotope ratios do not match any found on Earth.
Isotopic ratios act as chemical fingerprints, helping scientists trace the origins of elements and determine whether rocks share a common source. While oxygen isotopes on Earth and the Moon have long shown similarities, sulphur isotopes were expected to do the same, until now.
“Before this, it was thought that the lunar mantle had the same sulphur isotope composition as Earth,” said James Dottin, lead author of the study. “That’s what I expected to see when analysing these samples, but we observed values very different from anything on Earth.”
Dottin and his team studied samples collected using a double-drive tube, a metal cylinder driven into the lunar surface by Apollo 17 astronauts Gene Cernan and Harrison Schmitt. The samples had been preserved in a helium chamber for over 50 years, ensuring pristine conditions for examination. Using secondary ion mass spectrometry, a technique unavailable in 1972, the researchers were able to identify the unexpected isotopic differences.
