The Earth in Space
The Earth in SpaceDay and NightThe Earth is a sphere (actually,
its an oblate spheroid a very slight rugby ball shape)The Earth
orbits the Sun in a path that is egg-shaped an ellipse. It takes
3651/4 days to orbit the Earth every 4 years we have an extra day a
leap year.The Earth rotates once in 24 hours. The side of the Earth
facing the Sun experiences daylight; facing away from the Sun it is
night.
Seasons
If the Earths axis was exactly at 90o to the plane of the orbit
round the Sun, day and night would last the same time all year
round 12 hours.
However, the axis is tilted so we have seasons.
If the axis is tilted towards the Sun, day lasts longer it is
Summer.If the axis is tilted away, day is shorter it is winter.
In spring and autumn, the axis is neither towards nor away from
the Sun. This is when day and night are the same length; the spring
(vernal) and autumn (autumnal) equinoxes.
