This is the Mariana Trench,
the deepest place on Earth.
It stretches 11 km (7 mi)
down below sea level.
But what if we made it even deeper?
Get a giant drill because
we're about to dig a hole
in one of the most hostile environments
on the planet.
Here in the Western Pacific,
the Mariana Trench isn't the most
popular travel spot.
It's frigid and bone-crushingly deep.
Not something you'd pick for your vacation.
So it's not surprising that
only a handful of people have ever visited it.
It's a long way to the Challenger Deep,
the deepest part of the Mariana Trench.
Drilling through it would be both expensive and dangerous.
You'd need to troubleshoot on the spot,
work in complete darkness
and survive cold temperatures.
You might not come back safe and sound.
OK, now that we've sparked your interest, it's time to buckle down
and get to work.
It would be costly to get to the bottom,
but it would be even more expensive
to start drilling through it.
You'd need very specialized equipment.
While the water temperature around
you would be just above freezing,
you'd need to worry more about the crushing pressure.
At the bottom of the Mariana Trench,
It would be 1,100 times the atmospheric pressure at sea level.
You wouldn't be able to survive in just a diving suit.
You'd need to jump into a submarine
designed to withstand such high pressure.
And all the drilling equipment would need to be
specifically designed for the depth.
Before you could start drilling,
you'd have another issue.
There would be no way to anchor your expensive drilling equipment
at the bottom of the Mariana Trench.
You'd need to find a way to stabilize your rig.
And if that's not bad enough,
you'd need to assemble everything on site.
Yeah, you'd be moving heavy pipes and drills around.
And you'd need to bring some powerful lights
because it would be dark.
The Mariana Trench is just too deep
for sunlight to reach.
OK, once you dealt with all that,
you could start drilling.
And that endeavor would bring even more surprises.
We know more about the surface of the Moon
than we know about Earth's ocean floor.
But one thing we do know
is that it can get hot.
In 2011, researchers drilled the Japan Trench,
just outside of Japan.
They went down 6.9 km (4.9 mi) and found
that the temperature below the sea floor was scorching.
At just 1 km (0.6 mi) down, the temperature reached
120 °C (248 °F).
Another challenge you'd face
would be the ocean crust itself.
It's composed of igneous rock, or hardened magma.
This would wear down your drill pretty quickly.
You'd need to keep replacing your drill bit.
And you better mark the hole with a re-entry cone.
At the bottom of the ocean,
it would be tough to find the spot you'd already been drilling.
It would be like lowering a long strand of spaghetti
into a 0.6 cm (0.2 in) funnel
at the deep end of an Olympic swimming pool.
Yeah, that's hard.
Just how deep into the Earth's crust
would you be able to drill?
Well, that depends.
How patient are you?
And how much money do you have to spend
on all that drilling equipment?
If you're thinking about drilling
all the way to the Earth's core,
forget it.
Oddly enough, drilling through the crust
from the deepest place on Earth
wouldn't help you get to the core faster.
No, that's because Earth isn't perfectly spherical.
Yeah, it bulges at the equator,
making the drilling distance
to the center of the Earth from the Mariana Trench longer.
If you wanted to drill all the way through the Earth,
you'd be better off starting your project near the poles
as they are closer to the Earth's core.
But you know what?
I'll leave that story for another WHAT IF.