Many layers of the Earth are hidden from view. What if we could drill through the center of the planet to the other side? What extreme forces and temperatures do we encounter deep within the planet?

Although drilling the Earth remains science fiction, scientists have some ideas about what might happen, based on experience with other drilling projects. Since the Earth is 7,926 miles (12,756 kilometers) in diameter, drilling all the way into the planet would require a massive drill and decades of work.

The first layer to be penetrated is the crust, which is about 60 miles (100 km) thick, according to the US. Geological Service. As the storm moved underground, atmospheric pressure increased. Every 10 feet (3 meters) of rock is equal to about 1 atmosphere of pressure, the pressure at sea level, Doug Wilson, a research geophysicist at the University of California, Santa Barbara, told LiveScience. “When you’re talking about a lot of mileage, it adds up very quickly,” he said.

The deepest man-made hole is the Kola ultra-deep well, which has a depth of 12.2 km. The pressure at its bottom is 4,000 times greater than at sea level. According to the World Atlas, it took scientists almost 20 years to reach this depth. And that’s still more than 50 miles (80 km) away from the next layer, the mantle, according to Earth layer data from the USGS. The mantle is a dark, dense layer of rock 1,740 miles (2,800 km) long that determines plate tectonics.

The boundary between the mantle and the core is called the “Moho” (short for “Mohorowicz gap”). In the 1950s and 1960s, scientists first tried to dig the seabed here with the Mohole Project, but they failed.

When trying to drill a planet, the hole you make will fail if we don’t continually pump drilling fluid into it. In deep-sea drilling and oil well drilling, this fluid is a mixture of mud containing heavy minerals such as barium. Wilson explained that the weight of the fluid balances the pressure inside the hole with the pressure of the surrounding rock, preventing the hole from collapsing.

Drilling fluid serves two additional roles: it cleans the drill bit to prevent sand and gravel from clogging the mechanisms, and it helps reduce temperatures, although it is nearly impossible to keep the bit cool in the deepest layers of the earth. For example, the temperature in the mantle is 2570 degrees Fahrenheit (1410 degrees Celsius). Because stainless steel melts, the drill had to be made from an expensive special alloy such as titanium, Wilson said.

After passing through the mantle, the storm will eventually reach the Earth’s core at a depth of approximately 1,800 miles (2,896 km). According to the California Academy of Sciences. This hot molten iron-nickel alloy will be particularly difficult to drill.

“This is going to cause a whole range of problems,” Damon Teagle, a professor of geochemistry at the University of Southampton in the United Kingdom, told LiveScience. A fiery outer core resembles drilling fluid and could possibly melt the drill if cool water is not pumped in.

Then, after 3,000 miles (5,000 km) the drill will reach the inner core; Here the pressure is so intense that the nickel-iron core remains solid despite the high temperature. “You will be under truly incredible pressure,” Teagle said; about 350 gigapascals, or 350 million times atmospheric pressure.

All this time the drill was being pulled towards the core by the Earth’s gravity. At the center of the nucleus, gravity will be like an orbit; virtually weightless. This is because the pulling force of the Earth’s mass is equal in all directions, Wilson said.

Then, as the drill moves towards the other side of the planet, the gravitational force will vary with the position of the drill, effectively pulling it “down” towards the core. The storm will have to work against gravity as it pushes “upward” toward the surface, outer core, mantle, and crust to reverse the downward journey.

If all these obstacles are overcome, the biggest challenge you’ll face once you reach the middle is that you still have “a long way to go” to get to the other side, Teagle said.