Though humans have been able to send man to the moon and even a giant-sized robot all the way to Mars, they have yet to explore an area that lies just 6km (3.7 miles) beneath the surface of the sea floor - The Earth's Mantle, a 3,000 km thick highly viscous layer that sits between the outer crust that we reside upon and the Earth's core. However, if some scientists have their way that is about to change.

The ginormous undertaking is being planned by an international team of scientists from the Integrated Ocean Drilling Program (IODP) whose mission is to 'Explore the Earth Under the Sea'. As you can imagine, this project that co-leader Damon Teagle describes as 'the most challenging endeavor in the history of science', is not for the faint of heart.

In order reach the Mantle as efficiently as possible and extract samples, the team has identified three areas where the Earth's crust is just 6 km deep, compared to the normal, which ranges from 60-100 km. However, given that all three lie in the middle of the Pacific Ocean these are not the easiest targets to get to, especially since they will have to lug along with them equipment long enough to reach 10 km - four to cover the depth of the Pacific Ocean and then six more to drill down into the Mantle.

Assuming that they are able to do this and firmly secure the equipment to the ocean floor, they will then be faced with the even bigger challenge of drilling a hole just 30cm wide from the ocean floor down to the Mantle, a task Teagle describes as 'the equivalent of dangling a steel string the width of a human hair in the deep end of a swimming pool and inserting it into a thimble 1/10 mm wide on the bottom, and then drilling a few meters into the foundations."

Added to that is the fact that the drill bits will have to be changed every 50 to 60 hours because the ones presently available in the market get corroded by the ocean's salt. Given that the scientists will have to guide down new drill bits accurately through the 30cm wide hole from a ship that is sitting four kilometers above, this could be a little tricky.

Besides the technical challenges, the scientists also face a financial hurdle - Finding countries willing to finance the project that they estimate will cost $1 billion USD. Though they have received substantial support from the Japanese Government, the rest of the world has not been as generous so far.

However, if the project does get funded and the scientists are able to actually extract samples, it will give us an unprecedented insight into the how our planet was formed and what causes natural disasters like earthquakes and volcanoes.

This is not the first time an attempt to reach the Earth's Mantle has been made. In the 1960's a team of US scientists managed to drill a few meters into the oceanic crust off Guadalupe Island in the eastern Pacific. While President John F. Kennedy lauded the effort, the project did not get much support after his demise and was shut down in 1966. In the 1980's a Russian project managed to drill down 12km into the earth's crust, whilst in 2011, oil giant Exxon Mobil managed to go just slightly beyond that in eastern Russia. However, while it was the deepest one to date - it did not go down vertically and ended up penetrating only the soft sedimentary rocks.

Will we ever find out how the earth was formed? Maybe, but not for at least another 10-15 years. That's because even if everything goes according to plan the IODP scientists don't expect to begin drilling before the end of the decade, which means that the earliest we will be able to have some answers is in the early 2020's.

Resources: cnn.com,smithsonian.com,wired.com