Why seasons happen: tilt, not distance
Seasons come from 23.5 degree tilt, not distance, since Earth stands closest to Sun in early January each year.
Tilt aims hemispheres toward Sun in turn
Earth leans 23.5 degrees, so June sun strikes north directly while south gets slanting rays. Northern summer holds 15 hour days and 30 percent more energy per square meter, while southern winter endures 8 hour days and long shadows.
Distance cannot explain seasons because Earth is closest in early January at 147 million kilometers. Northern winter happens at perihelion, proving tilt rules, while southern summers grow hotter with 7 percent stronger January sunshine.
Solstices, equinoxes and polar extremes
Solstices fall near June 21 and December 21 with longest and shortest days, equinoxes near March 21 and September 23 with 12 hour days worldwide. After solstice days shorten or lengthen by 2 minutes daily in mid latitudes like 45 degrees.
Tropics between 23.5 north and south never feel true winter, staying above 18 degrees year round. Beyond Arctic circles sun never rises for months of polar night, then never sets for midnight sun, swinging from minus 40 to plus 10 degrees.
- Cause: 23.5 degree tilt, not distance
- Closest Sun early January at 147 million kilometers
- Solstices June 21 December 21, equinoxes March 21 September 23
- Tropics always above 18 degrees
- Polar night lasts months beyond 66.5 degrees