🔍 Key Concepts

• Meaning of upper transit vs lower transit of a celestial body • What the meridian is in celestial navigation and what kind of line a meridian represents on the Earth • Relationship between a body being on your meridian and the type/orientation of the resulting line of position (LOP)

💭 Think About

• When a star is at lower transit relative to your position, where is it with respect to your local meridian? Think about its bearing (north/south/east/west). • If your observation places the star on your meridian, what kind of circle (or line, in practice) does that define on the Earth’s surface? Is it more like lines that run north–south or east–west? • Compare: which of the choices describes something that lies along a meridian, and which describe something that lies along a parallel or some other line?

✅ Before You Answer

• Be clear on what lower transit means: the star crossing your meridian below the pole (opposite side from upper transit). • Identify whether a meridian is associated with longitude or latitude. • Confirm which type of chart line (north–south or east–west) best matches the orientation of the LOP when a body is on your meridian.