Final answer:
To map a new planet, a scientist would locate the equator by identifying the midpoint between the poles, and establish a prime meridian, which would act as a starting point for longitudinal measurements. These are essential for creating a coordinate system akin to Earth's latitude and longitude.
Step-by-step explanation:
To locate a newly discovered planet's equator, a scientist would find the midpoint between the planet's poles, analogous to how Earth's equator is the midway point between the North and South Poles. The equator is the line where the sun is directly overhead at noon during the equinoxes, typically occurring in March and September.
To establish the prime meridian, by convention on Earth, it passes through Greenwich, England with a longitude of 0°. On another planet, scientists would need to agree upon a starting point. This prime meridian would then serve as the reference line from which east-west locations, or longitudes, are measured.
These two imaginary lines are integral to the coordinate system used by geographers and cartographers, enabling them to map the planet accurately. Learning the coordinate system of latitude and longitude provides understanding of the apparent motion of celestial bodies and locations on Earth or any planetary body.