It’s almost as if lunar researchers got jealous of all the attention their Martian colleagues have been receiving for their discovery of water ice on Mars, and decided to compete: Lunar researchers say they’ve discovered trace amounts of water inside some moon rocks brought back by NASA‘s Apollo astronauts.
A new study of volcanic glass pebbles that date from 3 billion years ago has revealed that although the planet is nearly bone dry today, it may have once harbored significant amounts of water in rocks deep below the surface. The findings challenge researchers’ understanding of how the moon formed around 4.5 billion years ago. The Moon is thought to have been created in a violent collision between Earth and another planet-sized object. Scientists thought the heat from this impact had vaporised all the water [BBC News].
Researchers studied beads of volcanic glass that formed from droplets of molten lava that spewed from fire fountains reaching down deep within the primitive lunar interior [SPACE.com]. As they report in the journal Nature [subscription required], they found higher amounts of water in the beads’ centers than at the edges, indicating that most of the water was boiled off by the heat of the volcanic eruptions. Before these cataclysms, researchers calculate that the moon’s interior may have had nearly as much water as the Earth’s upper mantle.
Scientists have a couple of theories regarding the water’s origins, all of which bring new questions. If that water in fact came from the Earth, then planetary geologists can be certain that our planet contained water 4.5 billion years ago. That would change the dynamics of models of Earth’s formations…. Alternatively, water could have been added after the moon was ejected into space but before it cooled [Wired News].
It’s worth pointing out that no one is suggesting that the water has ever accommodated life; that water is trapped inside rocks and any that escaped could not accumulate in substantial amounts on the moon’s surface because of the low gravity and lack of atmosphere [Science News].