Compass rose

A compass rose or compass star, sometimes called a wind rose or rose of the winds, is a polar diagram that shows the directions we use to find our way. It displays the four main directions, called the cardinal directions: north, east, south, and west. These directions help us understand where we are and where we are going.

You can find compass roses on many tools that help with navigation. They appear on compasses, including magnetic ones, which show which way is north using a magnet. They are also used on maps, like those with compass rose networks, and on monuments that celebrate navigation.

Compass roses are very important in many navigation systems. They are used in nautical charts for ships, non-directional beacons (NDB), VHF omnidirectional range (VOR) systems for airplanes, and even on modern satellite navigation devices such as the "GPS". These tools help people and vehicles move safely from one place to another.

Types

Most human groups recognize four main directions, usually named after local features like hills or the sea, or after celestial bodies like the sun. These directions help people find their way around.

The ancient Greeks had separate systems for directions and winds. Over time, these systems mixed, and wind names began to represent directions. Scholars like Aristotle and Timosthenes developed systems of winds to help with navigation. The Romans later adopted and adapted these systems, using Latin names.

The sidereal compass rose uses the positions of stars in the night sky to mark directions. Arab navigators in the Red Sea and Indian Ocean used a 32-point system based on stars before the year 1000. In the Northern Hemisphere, the Pole Star, Polaris, helped mark north and south, while the Southern Cross was used in the Southern Hemisphere.

In Europe, seafarers developed their own 8-wind system using names from Mediterranean languages. This system was later expanded to 32 points, with special names for the main directions and combinations for the others.

Depiction on nautical charts

In old maps from the 1300s, compass roses were simple lines showing directions. These lines were colored to show different wind directions. One of the first fancy compass roses was drawn by Cresques Abraham from Mallorca in his Catalan Atlas from 1375.

Later, map makers added many fancy compass roses to their charts. They used special signs to show north, like a star or an arrow. Some even used a cross to point toward Jerusalem. Compass roses were also drawn on special ship boards to track directions.

Modern depictions

A modern compass rose looks like two rings, one inside the other. The outer ring shows the true directions, while the inner ring shows magnetic directions. True north is the point where the North Pole is located on Earth, and magnetic north is where a compass needle points. These two directions are not always the same, and the difference between them is called variation.

Most modern compasses show eight main directions, such as North, Northeast, East, and so on. Some maps and signs use fewer directions, like just North, East, South, and West. Airports often use a compass rose with twelve directions to help adjust airplane compasses. There are also compass roses with sixteen or thirty-two directions, which help in giving very exact directions.

Use as symbol

The compass rose is used as a symbol in many places. For example, the NATO symbol uses a four-pointed rose, and Outward Bound uses it as a logo for schools around the world. An 8-point compass rose was the logo of Varig, a big airline in Brazil, and it is also a feature in the logo of the Seattle Mariners Major League Baseball team.

Other groups use it too, like the Hong Kong Correctional Services, the worldwide Anglican Communion of churches, and IBM for its System/360 products. It is also the logo of Spain’s distance learning university, UNED, and appears on the seal and flag of the Central Intelligence Agency in the United States. The blog LessWrong also uses a compass rose as its logo.

In popular culture

The Compass Rose is a collection of short stories written by Ursula K. Le Guin in 1982.