A research collaboration between the Chinese Academy of Sciences and the University of Hawaii is trying to understand the distribution and concentration of water on the Moon.
The team scanned the surface of the Moon using a spectrometer to detect traces of water on surface minerals. This is the first in-situ detection of water on the Moon.
In 2009, China’s Chang’e 5 lunar lander made the first real-time water detection during an orbital mission.
Fast forward to December 2020, the lunar lander is making another historic first by taking spectroscopic images of water on the Moon.
Shuai Li, Assistant Professor of Earth Sciences at the University of Hawaii, explains how a spectrometer can see colors that are undetectable to the human eye, saying, “Our eyes can only see certain colors. Based on the colors, we can say different things, can’t we? The ocean is blue, the Earth is blue, the trees are green. The same principle can be applied to colors that we cannot see – or to waves electromagnetic waves at different frequencies, which our eyes cannot see.
“Interestingly, water has its own unique color in the infrared region. That’s where we can’t see. So when you see a ‘color’ in that frequency, you can immediately tell it’s water,” Li told HPR.
However, this is not the kind of water we drink every day. The team has yet to determine whether what they detected are water molecules or hydroxide (OH-) – a chemical with a molecular structure very similar to water.
“The Moon is drier than the driest desert on Earth,” Li joked.