Moon’s Liquid Water Mystery
August 30, 2013
Scientists have discovered evidence that liquid water once existed inside the moon. Where the water came from, however, is a something of a mystery. A NASA instrument called the Moon Mineralogy Mapper detected molecules of hydrogen and oxygen, called hydroxyl, in the center of an impact crater called Bullialdus. The mapper flies aboard the Indian lunar orbiter Chandrayaan-1. Hydroxyl is found in liquid water. The presence of hydroxyl indicates that a massive amount of water ice currently exists near the surface of the moon. This finding coincides with a recent discovery that moon rocks brought to Earth by the Apollo missions over 40 years ago contain evidence that a large quantity of water ice exists near the moon’s surface.
Many scientists think the ice may have formed from water that was forced up from deep underground by the warm interior of the moon. Some scientists, however, suggest that the water may have been deposited near the surface by the impact of many icy comets. If the water was present during the moon’s formation, it may change our theories on how the moon formed and how it changed as it cooled.
Scientists have long suspected that craters near the poles of the moon hold water ice. The water ice can survive because the craters are always in shadow, hidden from the sun’s warming rays. However, the newly discovered water was found in a crater near the moon’s equator.
Findings from moon rocks and orbiting satellites have revealed that liquid water once existed inside the moon. (Lunar and Planetary Institute)
Evidence for water ice below the moon’s surface has been growing in recent years. For example, NASA launched the Lunar Crater Observation and Sensing Satellite (LCROSS) mission in 2009. The spacecraft’s mission was to crash into the moon’s surface at a high speed. A separate instrument then flew through the debris kicked up by the impact to reveal the composition of the material blasted out into space. Other satellites and instruments on Earth observing the debris found it contained a large amount of water.
The existence of so much water ice on the moon could also impact future space missions in several ways. For example, people attempting to colonize the moon could collect the ice to obtain a supply of fresh water. Water molecules could also be split into pure oxygen and pure hydrogen to produce rocket fuel. There are already private companies attempting to reach the moon in order to investigate and possibly exploit the water resource.
Additional articles in World Book:
- Space exploration
- How the Moon Was Born (a special report)
- Rocket Man (a special report)
