Description: Navigation is the process of finding out where on Earth or where in space you are, your intended direction of travel, and how to get to where you want to go. Historically, the Sun and stars played an important role in navigation. At the simplest level, in a clear night in the northern hemisphere you can use the North Star to determine where north is and choose your direction of travel accordingly. In the southern hemisphere the Southern Cross points towards south. Prior to the development of modern navigational equipment, "celestial navigation" was essential for navigation. Navigators would determine the angle of the Sun above the horizon at noon to deduce their latitude, and the comparison of the time of local noon (highest sky position of the Sun) with a clock showing Greenwich Mean Time to determine their longitude. Modern navigation mostly relies on signals from GPS and similar satellite systems.

Related Terms:

• Latitude
• Longitude
• Southern Cross

Term and definition status: This term and its definition have been approved by a research astronomer and a teacher

The OAE Multilingual Glossary is a project of the IAU Office of Astronomy for Education (OAE) in collaboration with the IAU Office of Astronomy Outreach (OAO). The terms and definitions were chosen, written and reviewed by a collective effort from the OAE, the OAE Centers and Nodes, the OAE National Astronomy Education Coordinators (NAECs) and other volunteers. You can find a full list of credits here. All glossary terms and their definitions are released under a Creative Commons CC BY-4.0 license and should be credited to "IAU OAE".