Earth's mysterious core may be encased by an ancient ocean floor that has mountains 5 times taller than Everest

Study suggests Earth 's core could be encased in an ancient ocean floor that features giant mountains five times the size of Mount Everest .

Researchers made the discovery after creating the most detailed map yet of the geology beneath our planet's southern hemisphere.

If confirmed, this "recycled" ocean floor would act like a "blanket" that keeps heat trapped inside the core.