links & resources
Solstices, Equinoxes, and the Polar Regions
From the perspective of the North or South Pole, every year is essentially one long day that lasts half a year and one long night lasting the other half. This has enormous impact on how much solar energy is received in different times of year, which in turn influences physical processes, such as the freezing and thawing of snow and ice, biological processes, such as migration, and the lives of people who live in polar regions.
If the Earth were perpendicular on its axis, everywhere on the planet would receive an equal amount of sunshine (and darkness) every day. But because of the tilt of the Earth on its axis (currently 23.5 degrees off the perpendicular), only two days a year