It’s all fun and games until the subterranean monsters show up.
Oh, sure, drill down to the mantle for scientific purposes. Oh, sure, it will be a good international scientific project. Oh, sure, it will answer lots of questions.
Didn’t Hollywood already make a dozen movies about why we don’t do this?
Was Jules Vernes right or wrong?
Just how different is the mantle than the modeling clay we used in the 3rd grade to make a model of the earth?
How, exactly, do we react when we set off a chain of events involving either 9.6 earthquakes on every continent on the earth, subterranean monsters, volcanoes all over the place, or Michael Bay directing every movie everywhere. OR ALL OF THEM AT ONCE.
See for yourself. This will only end badly.