In astronomy and classical mechanics, the empirical laws that accurately describe and govern the motion of planets around the Sun are collectively known by which name?

Introduction / Context:
Planetary motion is one of the earliest and most important topics in astronomy and physics. Before modern gravitational theory, astronomers observed how planets move across the sky and summarised these observations in the form of simple laws. These empirical relationships describe how planets orbit the Sun and paved the way for the development of universal gravitation. This question asks you to identify the correct set of laws associated specifically with planetary motion.

Given Data / Assumptions:

• We are dealing with the motion of planets around the Sun.
• The laws in question are empirical, derived from careful observations.
• The options include famous laws from mechanics, chemistry, and logic.

Concept / Approach:
Johannes Kepler, using the observations of Tycho Brahe, formulated three famous laws of planetary motion. These laws describe that planets move in elliptical orbits with the Sun at one focus, sweep out equal areas in equal times, and relate the square of the orbital period to the cube of the semi-major axis. Newton later showed that these laws are a consequence of his law of universal gravitation and his three laws of motion. However, the specific name for the set of planetary motion laws is associated with Kepler.

Step-by-Step Solution:
Step 1: Recognise that the question is about the motion of planets in their orbits around the Sun. Step 2: Recall that Kepler gave three laws describing orbits, areas swept, and period–radius relationships for planets. Step 3: Match this description with the options given and identify the option that explicitly refers to planetary motion. Step 4: Select “Kepler laws of planetary motion” as the correct answer.

Verification / Alternative check:
Newton laws of motion are general laws applying to all bodies, not just planets. Avogadro laws relate to gases and the relationship between volume and amount of substance. De Morgan laws are associated with logic and set theory. Only Kepler name is directly and traditionally linked to the laws that describe planetary motion around the Sun. This cross-check ensures the correct identification.

Why Other Options Are Wrong:

• Newton laws of motion: These are fundamental mechanical laws about forces and motion, but they are not the specific empirical laws that originally described planetary orbits.
• Avogadro gas laws: These refer to relationships in gas behaviour, such as equal volumes of gases containing equal numbers of molecules at the same temperature and pressure, and are unrelated to planetary motion.
• De Morgan logical laws: These are rules in Boolean algebra and logic concerning negation and logical operators, and have nothing to do with astrophysics.

Common Pitfalls:
Students sometimes confuse the names Newton and Kepler because both are associated with celestial mechanics. Newton explained why planets follow Kepler laws, but the observational laws themselves carry Kepler name. Another source of confusion is thinking that any famous scientist listed must be the correct choice. Instead, focus on which name is historically tied to planetary motion.

Final Answer:
The laws that govern planetary motion around the Sun are called Kepler laws of planetary motion.