What does the Greenwich Hour Angle (GHA) represent?

The Greenwich Hour Angle (GHA) represents the longitude coordinate of a celestial object as it appears on the celestial sphere. It indicates how far west or east a celestial body is from the Prime Meridian, which is located at zero degrees longitude. This measurement is expressed in degrees, with a full 360 degrees corresponding to a full rotation around the Earth.

When astronomers or navigators want to determine the position of a celestial body, they utilize the GHA to calculate its angular distance from the Prime Meridian, which assists in pinpointing its exact location relative to Earth’s longitude. This is crucial for navigation, especially when using celestial navigation techniques.

The other options do not accurately capture the essence of GHA. For instance, while latitude pertains to the position north or south of the equator, and local solar time relates to the sun's position in the sky for a given location, neither addresses the specific measure of angular distance from the Prime Meridian that GHA represents. Thus, B reflects the correct concept of GHA as it directly relates to longitude on the celestial sphere.