Since 2008, we’ve known that there is water on the moon. The lack of atmosphere and a magnetic field means that most of the water on our satellite’s surface would be immediately stripped by the sun. However, that doesn’t apply within the Moon’s interior; an analysis of Apollo 15 and Apollo 17 moon rocks almost a decade ago revealed small amounts of water within volcanic glass beads. Now, research suggests that there actually may be a whole lot of water in the moon’s interior.
We learn most of what we know about objects in space through light. Orbital spectrometers can measure the light bouncing off a planet or moon (or measure the light from a star, for further-away objects) and examine the wavelengths. By looking at what is reflected and what’s absorbed, scientists can get a better idea of what elements and compounds are present on the surface. The problem is these spectrometers also measure heat, and the surface of the moon gets very hot during the day. This crowds out readings that could indicate water on the moon.