Start at the edge of space, fall through the sky, and keep going. Beneath your feet are 6,371 kilometres of rock and metal that nobody has ever seen.
For this trip you are indestructible. Nothing can hurt you. As you fall, we will tell you what a real body would be going through.
Scroll to fall
100 km above the ground
You start 100 km up, at the line many people use to mark where space begins. Below you is a thin blue glow: all the air there is.
Half of it sits in the lowest 5.5 km. If Earth were a basketball, the air you could breathe would be thinner than a sheet of paper.
A real body: Almost no air at all. Without a suit, you'd black out in about fifteen seconds.
25 km above the ground
Up here, a thin layer of ozone soaks up most of the Sun's harsh ultraviolet light. Without it, life on land would be scorched.
It's thinner than you'd think. Bring all of it down to the ground and it would make a layer about 3 mm thick.
A real body: A fortieth of the air at sea level, and −51 °C. You'd need a pressure suit, like a high-altitude pilot.
8 km above the ground
You fall into a thunderstorm. Nearly all of Earth's weather happens down here, in the lowest slice of the sky.
Lightning strikes somewhere on Earth about 44 times every second.
A real body: About a third of the air at sea level, nearly as high as Everest. Breathing this, you'd pass out within minutes.
0 km down
And then the ground. Everything any human has ever done happened on the thin skin you just landed on.
Now keep going. Earth is 6,371 km deep, and we've barely scratched it.
A real body: You're perfectly fine. This is the only place we know of where a human can live without protection.
12 km down
In 1989, Soviet scientists drilled 12.2 km into the rock of Russia's far north. The Kola Superdeep Borehole is still the deepest hole humans have ever made.
They stopped because the rock down here was 180 °C, far hotter than expected, and started to behave like putty around the drill.
A real body: Thousands of times Earth's air pressure, and hot enough to cook. Nothing has ever gone deeper. Everything below is known from earthquake waves.
150 km down
About 35 km down you left the crust behind. This is the mantle, and here the rock is so hot it slowly flows, like very thick toffee, even though it's solid.
It creeps a few centimetres a year, about as fast as your fingernails grow, and drags the continents along with it.
A real body: Fifty thousand times Earth's air pressure and around 1,300 °C. The rock glows, but it's still solid.
520 km down
Between about 410 and 660 km down, the squeeze turns the rock into a deep blue crystal called ringwoodite, which can hold water inside it.
In 2014, scientists found a tiny diamond from Brazil carrying a speck of ringwoodite full of water. This layer may hold as much water as all the oceans.
A real body: Nearly 200,000 times Earth's air pressure and about 1,500 °C. The water isn't liquid: it's built into the crystals.
2,890 km down
At 2,890 km, the rock ends. Below is an ocean of molten iron and nickel, and the whole core is bigger than the planet Mars.
As this metal churns, it makes Earth's magnetic field. That invisible shield turns aside the solar wind, points every compass north and lights up the auroras.
A real body: 1.4 million times Earth's air pressure and about 3,700 °C. The iron here flows about as easily as water.
6,371 km down
Below 5,150 km the iron turns solid again. It's even hotter, but the pressure is so great the iron can't melt.
Nobody knew it was here until 1936, when the Danish scientist Inge Lehmann noticed earthquake waves bouncing off something hard inside the liquid core.
You're at the centre of the Earth, 6,371 km below where you landed.
A real body: 3.6 million times Earth's air pressure and around 6,000 °C, about as hot as the surface of the Sun.
From the edge of space to the centre of the Earth. You made it.
You'd pass the deepest hole ever dug after just 12 km, where the rock is already 180 °C. Everything below is known only from earthquake waves.
Deeper, the rock is so hot it slowly flows. At 2,890 km you'd reach an ocean of molten iron bigger than the planet Mars.
At the centre is a solid iron ball at about 6,000 °C, as hot as the surface of the Sun, under 3.6 million times the air pressure you're feeling now.
12.2 km. The Kola Superdeep Borehole in northern Russia, finished in 1989, is still the deepest hole. Drilling stopped because the rock was 180 °C and turning soft.
Iron and nickel. The outer core is liquid, and the inner core, starting about 5,150 km down, is solid because the pressure is too great for it to melt.
The inner core is around 6,000 °C, about the same as the surface of the Sun. The outer core is around 3,700 °C or more.
Ignoring the heat and air resistance, you'd fall all the way through and come out the other side in about 38 minutes, then fall back, again and again.
