# Orthodromic distance

- Author:
- Šárka Voráčová

A

**great circle**, also known as an**orthodrome**, of a sphere is the intersection of the sphere and a plane that passes through the center point of the sphere. A great circle is the largest circle that can be drawn on any given sphere. The grear-circle distance or orthodromic distance is the shortest distance between two points on the sphere. Suppose two points on the sphere. Orthodromic distance is*R.w [km]*, where R = 6378 km and Problem: Measure the shortest air distance from London (51°N 0°) to Buenos Aires (–34°S -60°W). As a reference surface use sphere with radius R = 6 378 km.Compare the resulting distance with
http://www.thetimenow.com/distance-calculator.php