Earth's Iron Core Is About the Size of Mars
Earth's inner core is a solid iron ball about 2,440 km in diameter - roughly the same size as Mars (2,439 km). This core is responsible for generating Earth's magnetic field.
About this fact
Deep beneath our feet lies a solid iron core that's about the same size as the planet Mars. Earth's inner core is a sphere of solid iron and nickel with a diameter of approximately 2,440 kilometers, while Mars has a diameter of 2,439 kilometers. This iron core is surrounded by a liquid outer core and is under such extreme pressure (about 3.6 million times atmospheric pressure) and temperature (around 5,000Β°C - as hot as the Sun's surface) that the iron remains solid despite the heat. The core is primarily responsible for generating Earth's magnetic field through the geodynamo process, where the movement of liquid iron in the outer core creates electrical currents that produce magnetic fields. Without this magnetic field, Earth would be vulnerable to harmful solar radiation and would likely have lost its atmosphere long ago, making life as we know it impossible.