A new study of samples from the Apollo 16 satellite reveals the moon’s hidden history

Scientists continue to piece together the complex history of the Moon using lunar samples collected during NASA’s Apollo missions more than half a century ago.

New analysis of lunar dust collected Apollo 16 astronauts in 1972 offers a clearer picture of the effects of asteroid collisions with the Moon, allowing scientists to reconstruct billions of years of lunar history. Conclusions can also help future crewed missions Scientists say they need to pinpoint valuable natural resources to build bases on the moon.

After landing in the cratered Descartes region of the lunar highlands, astronauts John Young, Charles Duke, and Ken Mattingly collected approximately 200 pounds (96 kg) of material from the lunar surface. Chemical analysis of the soil-like pebbles in these samples, which the astronauts collected while raking the landing site, revealed the presence of various noble gases, including argon and xenon. These trapped gases serve as useful timestamps for space weather processes such as the solar wind and asteroid impacts that have helped shape and reshape the Moon’s surface over billions of years.

Most of the samples collected during the Apollo era have already been thoroughly studied. To take advantage of new science and technology, NASA cracked one of the last sealed samples collected during the Apollo 17 mission just two years earlier. Much of our knowledge of the Moon and its evolution comes from these samples, including the true age of the Moon. 40 million years older than we thought.

But researchers say this new study of trapped lunar gases is already opening new chapters of lunar history.

“We can build a much more complete picture of the history of this part of the Moon during the early solar system, where stronger impacts on the lunar surface in the first billion years or so were replaced by less intense periods two billion years ago or so,” said lead study author Mark Nottingham from the University of Glasgow in the UK statement.

Analyzing samples collected during the Apollo 16 mission, Nottingham and his colleagues used mass spectrometry techniques to catalog the various noble gases and their abundance in the samples, which helped them “determine how long the samples spent exposed to the surface of the Moon or near her.” This is stated in Nottingham’s statement.

The chemical composition of the gases trapped in these “regolith breccias“—the result of the melting of lunar dust into rock by asteroid impacts—show that they have been exposed to the solar wind and asteroids for a long time.

The specific age of the exposure varied widely between the samples, from 2.5 billion years ago to less than a billion years ago, suggesting that the lunar soil around the landing zone is “well mixed,” with some of it brought to the surface by recent impacts, the new study reports.

Nottingham says studies like this one will help scientists better understand where noble gases and other elements might be found on the moon and in what quantities, helping humanity better plan future lunar exploration.

“It’s amazing to think that the samples brought back by Apollo 16 more than half a century ago still hold the secrets of the moon’s history, and that they can help shape the way we explore the solar system for decades to come,” Nottingham said. .

This study is described in a paper published October 15 in the journal Meteoritics & Planetary Science