Where is it? On the Celestial Sphere

Longitude and Latitude On Earth: Longitude is how far you are, in degrees, East or West of the “Prime Meridian” which goes from the North Pole through Greenwich England and on to the South Pole. Latitude is how far you are, in degrees, north or south of the Equator which is 0°. The North Pole is 90° North.

Right Ascension (RA) On the Celestial sphere: Right Ascension is like Longitude. The Right Ascension of an object is how far east an object is from a line that runs from celestial pole to the other through the vernal equinox. Unlike longitude Right Ascension is measured in Hours, Minutes and Seconds. 24 hours is once around.

Declination (Dec) Declination is how far an object is north or south of the celestial equator in degrees. It is just like latitude in everyway. The Equator is 0° Declination, The celestial poles are at 90° North and South Declination The Tropic of Cancer is a declination line along about 23°27’ North. The Tropic of Capricorn is

The Location of Celestial Objects All Celestial objects can be located: In the sky at a given time with Altitude and Azimuth But that changes due to the motion of the celestial sphere. On the Celestial Sphere with Right Ascension and Declination. The RA and Dec of almost all celestial objects stay the same. Except… The Objects in the Solar System

The Motions of the Sun, Moon and Planets Ancients noticed that the Sun, Moon, Planets (and the other objects in the solar system) move across the celestial sphere. “Planet” means wanderer in Greek. So…their Right Ascension and Declination are always changing. They move on paths that are close to, and intersect the ecliptic They also move with the Celestial Sphere