africa amazon river arctic arctic circle asia axial tilt brazil celestial equator celestial sphere climate clockwise colombia congo river coriolis effect dry season earth eastern hemisphere ecuador equator equinox europe french guiana geographic coordinate system guyana hemisphere high pressure indonesia land hemisphere marshall islands micronesia milky way moon north north america north pole palau planet season solstice south america southern hemisphere sphere suriname tropic of cancer tropics venezuela water hemisphere western hemisphere wet season winter solstice world population