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].
Author's Note: Could you dig a hole all the way to the Earth’s mantle?
As a child in the 1960s, I loved reading comic books, and one of my favorites was the Classics Illustrated version of Jules Verne's novel "Journey to the Center of the Earth." I particularly was fascinated with the cover illustration, in which the characters are floating in the subterranean sea passage that Verne imagined and are under attack by prehistoric sea monsters. The vividness of that image contributed to my disappointment a few years later, when I learned in elementary school science class that the Earth was filled with molten rock, which seemed considerably less interesting.
- American Museum of Natural History. "Ultra-High-Pressure Experimentalist Who Studies the Deep Earth." Amnh.org. Undated. (Nov. 4, 2012) http://www.amnh.org/explore/resource-collections/earth-inside-and-out/ultra-high-pressure-experimentalist
- Encyclopaedia Britannica. "Chemical element—the Earth's Mantle." Britannica.com. Undated. (Nov. 5, 2012) http://www.britannica.com/EBchecked/topic/108636/chemical-element/81230/The-Earths-core#toc81231
- Cooper, Charles. "Journey Planned to the Center of the Earth." Cbsnews.com. March 28, 2011. (Nov. 2, 2012) http://www.cbsnews.com/8301-501465_162-20047788-501465.html
- Flatow, Ira. "Drilling to the Mantle of the Earth." Npr.org. March 25, 2011. (Nov. 2, 2012) http://www.npr.org/2011/03/25/134855888/Drilling-To-The-Mantle-Of-The-Earth
- Jackson, Ian. "The Earth's Mantle: Composition, Structure and Evolution." Cambridge University Press. 1998. (Nov. 5, 2012) http://books.google.com/books?id=RlixwcPYF2AC&printsec=frontcover&dq=%22earth's+mantle%22&hl=en&sa=X&ei=V9WXUKKeB8m10AHdvYDwCA&ved=0CC8Q6AEwAA
- Kaufman, Marc. "Space Odyssey: Scientists go to the extremes to define the secrets of extraterrestrial life." Washington Post. Feb. 27, 2011. (Nov. 7, 2012) http://www.washingtonpost.com/wp-dyn/content/article/2011/02/18/AR2011021805058.html?nav=emailpage
- Matsu'ura, Mitsuhiro. "Reproducing Core-Mantle Dynamics and Predicting Crustal Activities Through Advanced Computing." Journal of the Earth Simulator. April 2004. (Nov. 5, 2012) http://www.jamstec.go.jp/esc/publication/journal/jes_vol.1/pdf/JES1-4.2-matsuura.pdf
- National Academy of Sciences. "Project Mohole: 1958-1966." Nas.edu. 2005. (Nov. 5, 2012) http://www.nas.edu/history/mohole/
- Osman, Jheni. "Mission to the mantle: Drilling through Earth's crust." New Scientist. July 3, 2012. (Nov. 3, 2012)http://www.newscientist.com/article/mg21428710.200-mission-to-the-mantle-drilling-through-earths-crust.html?full=true
- ScienceDaily. "Mapping the Moho With GOCE." Sciencedaily.com. March 9, 2012. (Nov. 4, 2012) http://www.sciencedaily.com/releases/2012/03/120309103810.htm
- ScienceDaily. "New Understanding of Earth's Mantle Beneath the Pacific." Sciencedaily.com. March 22, 2012. (Nov. 4, 2012) http://www.sciencedaily.com/releases/2012/03/120322142159.htm
- Teagle, Damon and Ildefonse, Benoit. "Journey to the Mantle of the Earth." Nature. March 24, 2011. (Nov. 2, 2012) http://www.nature.com/nature/journal/v471/n7339/full/471437a.html
- U.S. Geological Survey (USGS). "Mantle (earth)." Usgs.gov. Undated. (Nov. 4, 2012) http://www.usgs.gov/science/science.php?term=690
- Yirka, Bob. "Scientists plan to drill all the way down to the Earth's mantle." Phys.org. March 25, 2011. (Nov. 2, 2012) http://phys.org/news/2011-03-scientists-drill-earth-mantle.