Yes, parts of the Moon are still molten inside. While the Moon is not entirely a ball of liquid rock like it might have been billions of years ago, scientific evidence shows that significant internal layers remain partially molten.
Understanding the Moon's Interior Structure
Like Earth, the Moon has distinct layers: a crust, a mantle, and a core. Scientists study seismic data, gravity measurements, and magnetic fields to understand these layers and their current state.
The Partially Melted Lower Mantle
Recent research provides insights into the Moon's deep interior. According to findings, the Moon's central core is surrounded by a significant layer in the lower mantle that is partially melted.
Specifically, the reference states:
- The core is surrounded by the partially (10 to 30%) melted layer of the lower mantle with a radius of 480 ± 20 km (thickness ~150 km).
This means a substantial ring of material deep inside the Moon, sitting just outside the core, is between 10% and 30% in a molten state. This layer is quite large, extending outwards to a radius of approximately 480 kilometers and having a thickness of about 150 kilometers.
The Lunar Core
The Moon's core itself is thought to be primarily solid or partially solidified. The reference also mentions that these results imply that 40% of the core by volume has solidified. This indicates that while the outer part of the core or the region just above it is partially melted, the innermost core is likely solid or becoming solid.
Key Takeaways
- The Moon is not entirely solid.
- A significant layer in the lower mantle is partially molten (10-30% melt).
- This partially melted layer is located just above the core.
- The core itself is believed to be partially solidified.
In summary, while the fiery, fully molten state of the early Moon is long past, there is indeed molten material present within its deep interior, specifically within a layer of its lower mantle.
