内容摘要：“I spend my entire day doing nothing, and thinking,” he said, leaning against the home’s stucco walls, by the concrete parking spaces that used to be the front yard. “So I’m happy when it’s time to go to work and I have something to do.”

“I spend my entire day doing nothing, and thinking,” he said, leaning against the home’s stucco walls, by the concrete parking spaces that used to be the front yard. “So I’m happy when it’s time to go to work and I have something to do.”

called Homo heidelbergensis — thought to be the last common ancestor betweenBut the new analysis using a different dating technique suggests the spears are younger, placing them about 200,000 years old. The new age means the hunting weapons may have been used by Neanderthals instead, according to research published Friday in the journal Science Advances.

Recent work has suggested that some Neanderthals mixed and mated with early humans. The balanced, well-crafted spears could help scientists understand what Neanderthals were capable of and how they worked together to hunt.The spears are “pretty sophisticated for something that old,” said study co-author Jarod Hutson with the Smithsonian National Museum of Natural History.This 2014 photo provided by researchers shows a set of wooden hunting spears estimated to be about 200,000 years old discovered in a coal mine in the German town of Schöningen. (Volker Minkus/Niedersächsisches Landesamt für Denkmalpflege via AP)

This 2014 photo provided by researchers shows a set of wooden hunting spears estimated to be about 200,000 years old discovered in a coal mine in the German town of Schöningen. (Volker Minkus/Niedersächsisches Landesamt für Denkmalpflege via AP)But it’s not yet clear why the new dating disagrees with previous estimates. Archaeologist Thomas Terberger with the University of Göttingen said more research is needed to be sure of the spears’ age and who used them to hunt.

“For the moment, I find the arguments interesting, but not absolutely convincing,” said Terberger, who had no role in the new study.

The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute’s Science and Educational Media Group and the Robert Wood Johnson Foundation. The AP is solely responsible for all content.The Chinese Academy of Sciences’ Sen Hu said he and his team received 5 grams of soil samples, then selected 578 particles for detailed analysis using electron microscopes.

They estimated the water abundance at less than 1.5 micrograms per gram, on the dry end of what’s been found in samples gathered over past decades from the moon’s near side. Measurements on samples from the near side have ranged between 1 microgram and 200 micrograms per gram.Given the limited sampling, it’s uncertain how widespread this dry condition might be, the scientists noted in their study published in the journal Nature.

“More far side samples are required for testing and further unraveling” how much water there is, Hu said in an email.It’s possible the impact that created this basin may have blasted water elements to the near side, leaving the far side depleted. Another possibility is that the vertical distribution of water could be different between the two hemispheres.