Thread:Lenhi/@comment-29834666-20160513212839/@comment-29834666-20160513213729

That doesn't mean lower mantle. It could mean the middle of the mantle. It's just not close to the mantle's surface.

The mantle's pretty darn huge, and pressure at the lower part is huge. The drill would've imploded if it was that far down. Also, the diagram in It Could've Been Great showed it close to (and actually above) the middle of the mantle, not the lower part.