Equator Overview and Facts

Overview

This lecture explains the concept, importance, and key facts of the equator, an imaginary line on Earth used for geographic reference.

Imaginary Lines: Latitude and Longitude

• Latitudes are horizontal imaginary lines on Earth's surface.
• Longitudes are vertical imaginary lines running from pole to pole.
• These lines help determine position, distance, and time zones.

The Equator: Definition and Characteristics

• The equator is an imaginary horizontal line at zero degrees latitude.
• It divides Earth into the Northern and Southern Hemispheres.
• The equator lies equidistant from the North and South Poles and is perpendicular to Earth's axis.
• It is called the "even maker" from Latin because it splits Earth evenly.

Key Facts about the Equator

• The equator is midway between the poles.
• Its surface is parallel to Earth's rotational axis.
• It measures about 40,075 km (24,901 miles) in length.
• 79% of the equator crosses water; 21% crosses land.
• The equator's exact location is not fixed due to Earth's irregular shape.
• Regions near the equator experience consistently warm weather and do not have four distinct seasons.
• Day and night lengths are almost equal all year near the equator.
• Night is roughly 14 minutes shorter than day at the equator.
• Sunrises and sunsets are brief, and the sun appears nearly perpendicular to the horizon most of the year.

Physical and Geographical Effects

• Earth bulges at the equator, making its radius about 43 km longer here (total: 12,750 km).
• The equator has Earth's fastest rotational speed (about 460 meters per second).
• This speed benefits spacecraft launched eastward.

Countries along the Equator

• The equator passes through 13 countries: Ecuador, Colombia, Brazil, São Tomé and Príncipe, Gabon, Republic of the Congo, Democratic Republic of the Congo, Uganda, Kenya, Somalia, Maldives, Indonesia, and Kiribati.

Key Terms & Definitions

• Latitude — Imaginary horizontal lines measuring distance north or south of the equator.
• Longitude — Imaginary vertical lines measuring distance east or west of the prime meridian.
• Equator — Zero-degree latitude line that divides Earth into northern and southern halves.

Action Items / Next Steps

• Review the names and locations of countries through which the equator passes.
• Memorize the main characteristics and effects of the equator for upcoming assessments.