Hopefully, a lot. As we explained previously, knowledge about the Earth's mantle is pretty limited, because we can't go there, and we've never had a pure sample of it. Instead, scientists have tried to figure it out by studying seismic waves and examining the molten rock that flows out of volcanoes. They've also tried to glean clues about the mantle's composition by studying meteorites, which are forged from the same space debris as our planet [source: Osman].
But all those sources leave a lot of questions unanswered. If scientists eventually get some of the mantle to study, they stand to gain some new insights about how the Earth was formed billions of years ago, how it developed into the core, mantle and crust, and how plate tectonics began. If they can learn more about the precise mix of chemicals and isotopes in the mantle, they can get a better sense of how the mantle transfers chemicals to the surface [source: Osman].
More important, they may learn exactly how movement of the mantle's fluid rock affects the Earth's crust, in particular how the tectonic plates push and pull against one another [source: Cooper] Knowing more about the mantle and how it interacts with the crust might someday even help us to predict events such as earthquakes and volcanic eruptions [source: Matsu'ura].
But one of the most tantalizing possibilities is that scientists might actually find life deep inside the Earth. We're not talking about the monsters that Jules Verne imagined in "Journey to the Center of the Earth," but rather tiny, primitive organisms called extremophiles, which have evolved to resist extreme pressures and high temperatures (such as the microscopic "worms from hell" found at the bottom of a South African gold mine).Scientists already have found such organisms in the deepest ocean floor. If they're able to exist even deeper in the Earth, scientists speculate that such organisms might contain unique enzymes or other characteristics that researchers could put to use in developing biotechnology. Even more importantly, they might help us to understand the physiological limits of life [source: Osman].