Scientists Explain Lack of Volcanic Activity on Moon

Scientists say there has not been a volcanic eruption on the moon for billions of years, however, they believe there is plenty of liquid magma deep under the surface.

The lack of volcanic activity has puzzled scientists, but research could shed some light on the reasons. A team led by Mirjam van Kan Parker and Wim van Westrenen from VU University Amsterdam, along with scientists from the University of Paris, have been examining moon rocks and even made their own moon rocks to experiment with.

Magma, which is typically less dense than the surrounding rocks, eventually pushes its way to the surface. “The lighter the liquid magma is, the more violent the upward movement will be,” the researchers said.

To create their own moon magma, Parker and his team created their own moon rocks and heated them up using strong electrical currents. Sometimes they compressed the rocks to create magma. Density measurements were taken of their magma leading to a conclusion.

Most of the magma they created was less dense than the surrounding rocks, so there should be some volcanic activity. But on the moon, Apollo astronauts found titanium-rich rocks near the surface.

The scientists concluded that large vertical movements must have occurred early in the Moon’s history, when titanium-rich rocks descended from near the surface all the way to the core-mantle boundary. “After descending, magma formed from these near-surface rocks, very rich in titanium, and accumulated at the bottom of the mantle – a bit like an upside-down volcano,” Parker said.

“Today, the Moon is still cooling down, as are the melts in its interior. In the distant future, the cooler and therefore solidifying melt will change in composition, likely making it less dense than its surroundings. This lighter magma could make its way again up to the surface forming an active volcano on the Moon,  but for the time being, this is just a hypothesis to stimulate more experiments.”