Special lines on the globe: the Equator, tropics, polar circles, and date line

Mapmakers draw a few special imaginary lines on globes and maps. The Equator is the line of 0 degrees latitude, halfway between the North Pole and the South Pole. It divides Earth into the Northern and Southern Hemispheres. The Prime Meridian is the line of 0 degrees longitude. It runs through Greenwich, England, and divides Earth into the Eastern and Western Hemispheres. The Tropic of Cancer, at about 23.5 degrees north, and the Tropic of Capricorn, at about 23.5 degrees south, mark how far north and south of the Equator the Sun can be straight overhead at noon. The area between them, called the tropics, is warm all year in most places, though high mountains there can be cold. The Arctic Circle, at about 66.5 degrees north, and the Antarctic Circle, at about 66.5 degrees south, mark the edge of the polar regions, where on at least one day each year the Sun never sets and on at least one day it never rises. The International Date Line runs roughly along 180 degrees longitude, on the opposite side of the world from the Prime Meridian. When you cross it going west, the calendar moves forward one day, and when you cross it going east, it moves back one day. The line zigzags around some countries and island groups so that each one can keep a single date.

This explanation is AI-generated and can occasionally be wrong. 🚩 Report