Final answer:
The mentioned equation x²/³ + y²/³ = a²/³ describes an astroid, which is parametrized by x = a cos³ t and y = a sin³ t in the realm of plane curves in mathematics. The subject also touches upon concepts of celestial mechanics and semi-major axes in orbits.
Step-by-step explanation:
The provided equation, x²/³ + y²/³ = a²/³, represents an astroid, which is a particular type of hypocycloid. This equation can be parametrized using x = a cos³ t and y = a sin³ t, where t is a parameter that varies from 0 to 2π. The astroid is a specific kind of parametric curve and is part of the study of plane curves within mathematics.
From the given information unrelated to the astroid question, we learn about various orbits in celestial mechanics. For example, the semi-major axis plays a vital role in determining the characteristics of an orbit since the square of the orbital period is proportional to the cube of the semi-major axis of the orbit. This is known as Kepler's third law of planetary motion.