Earth's Rotation around its Axis
Earth rotates around its own axis through360° once every 24 hours. This is the cause of day and night. If we divide 360° by 24, we get 15°. In other words, it takes the Earth 1 hour to turn through 15°.
The Earth's polar axis tilts at an angle of 23,5° with its orbital plane around the sun. As put by A.P. Herbert: "The Earth goes round the sun with its head on one side" (Herbert, page 39). This inclination is responsible for the climate changes and the seasons experienced on Earth.
|During summer in South Africa Earth is closest to the sun and the southern (bottom) part of Earth is tilted towards the sun; during winter it is tilted away from the sun.|
|Earth's movement around the Sun||Declination|
|Sundial Home Page||© Helga Nordhoff (2001-2008)|