🔍 Key Concepts

• Geographical Position (GP) of a celestial body on the Earth’s surface • Relationship between declination and another angle that fixes longitude, similar to how declination is like latitude • Difference between local hour angle, Greenwich hour angle, and other celestial coordinates like right ascension

💭 Think About

• Which coordinate, when combined with declination, gives you a unique point on the Earth directly under the body (its GP)? • Think of declination as similar to latitude. What celestial coordinate acts like longitude, specifically measured from the Greenwich meridian? • Among the choices, which quantity is directly tied to Earth’s rotation relative to Greenwich, and not dependent on the observer’s position?

✅ Before You Answer

• Be clear on what declination represents on the celestial sphere and its Earth-surface counterpart. • Identify which option represents an angle measured westward from the Greenwich meridian. • Eliminate any choices that depend on the observer’s position rather than defining the body’s fixed GP.