在线英语听力室_免费在线英语听力学习网站

When astronaut Alan Shepard took his first swing at a golf ball on the moon, he hit more dirt than ball. The dust he kicked up reinforced the idea that the moon is one big sand trap. But looks can be deceiving. Now, scientists reanalyzing lunar samples say that our satellite is at least a hundred times wetter than we thought. The results appear in the Proceedings¹ of the National Academy of Sciences.

Astronauts manning the Apollo missions brought home plenty of moon rocks. And in 40 years of looking at those samples, no one ever found a trace of water. That could be because the collision that made the moon in the first place was so hot that volatile² elements like hydrogen, a key component³ of H2O, largely burned away.

Now, using a technique that can identify elements present in just a few parts-per-billion, scientists have taken another look at three lunar samples, two from Apollo missions and one meteorite⁴ found in Africa. And they detected hydroxyl, the HO that’s left behind when a rock crystallizes from magma containing water.

The results suggest that water may be ubiquitous in the interior of the moon. Although there’s probably not enough to qualify as a water hazard.

Thanks for the minute for Scientific American's 60-Second Science. I'm Karen Hopkin.