The Earth is the third planet from the sun and the sixth largest planet in the solar system. It is not a perfect sphere, with its equator being wider than its polar diameter. The Earth has layers including a crust, mantle, outer core, and inner core. The Earth rotates once every 23 hours, 56 minutes and 4.1 seconds as it orbits the sun at a speed of 106,000 km/hr along its 930,900 km circumference orbit. Earthquakes and volcanic eruptions originate from movements within the Earth's layers.