Oceans, and the innards of Earth itself, are the final frontiers of our planet. Expect amazing discoveries as explorers document more and more of this unseen realm. Hulton Archive/Getty Images hide caption toggle caption Hulton Archive/Getty Images Opinion 13.7: Cosmos And Culture The Other 10 Most Important Questions In Science September 18, 2013 Science may seem advanced, may even be advanced, but that doesn't mean there aren't still plenty of questions left to ask and answer. A new book catalogs 20 of the biggest questions outstanding. Physicist Marcelo Gleiser looks the list over and ponders some of the subjects keeping scientists awake at night.