Quick facts

15 surprising facts about the inside of the Earth

Quick facts for the curious, each one linked to a longer article if you want to dig deeper.

By Martin Krpelan · · 2 min read

  1. The center of the Earth is about as hot as the surface of the Sun, roughly 5,400 °C. Inner core
  2. Yet the inner core is solid. The pressure is so high that iron can't melt. Inner core
  3. The deepest hole ever drilled is 12,262 m deep, only 0.2% of the way to the center. Kola borehole
  4. It took 19 years to dig, and the hole is only 23 cm wide. Kola borehole
  5. The crust is less than 1% of the Earth's volume. Relative to the planet, it is thinner than the skin of an apple. Crust
  6. The mantle is solid rock, but it flows, about as fast as your fingernails grow. Mantle
  7. The mantle's transition zone may hold more water than all the oceans, locked inside crystals. Mantle
  8. The most common mineral on Earth is one almost nobody has seen: bridgmanite, in the lower mantle. Mantle
  9. The outer core is liquid metal, and its currents create the magnetic field that protects the atmosphere. Outer core
  10. The magnetic field flips. The last time north and south swapped was about 780,000 years ago. Outer core
  11. The inner core was discovered by a woman who lived to 104, Danish seismologist Inge Lehmann, in 1936. How we know
  12. Falling through the Earth would take about 38 to 42 minutes, and you would hit 28,000 km/h at the center. Falling through the Earth
  13. Digging from the US gets you to the Indian Ocean, not China. Antipodes
  14. Only about 15% of land has land on the opposite side of the world. Antipodes
  15. Bacteria live 3 km underground in a South African gold mine, fed by radioactive rock. Deepest places

Sources

Keep digging

Inside the EarthThe layers of the Earth, from crust to coreA guided trip through the Earth's crust, mantle, outer core and inner core: how deep each layer is, what it's made of, how hot it gets and how we know.The deepest holeThe Kola Superdeep Borehole: the deepest hole ever dugIn 1970 Soviet scientists started drilling toward the mantle. After 19 years they reached 12,262 m, still the deepest point humans have reached. Here is what they found.GeographyAntipodes: what's on the other side of the EarthYour antipode is the point exactly opposite you on the globe. Most are in the ocean. Only 15% of land has land on the other side. See the map and the famous pairs.