Which of these exoplanet characteristics is MOST difficult to explain with the Nice model of planetary system formation?
A) Exoplanets that orbit in an opposite direction from their star's rotation.
B) Gas giants with orbits smaller than Mercury.
C) The relative proportion of gas giant and terrestrial planets in exoplanet systems.
D) The existence of free-floating planets.

Question

Quizplus · Accepted Answer

The Nice model primarily explains the migration of giant planets within our solar system and their impact on the Kuiper belt and asteroid belt. It does not easily account for exoplanets that have retrograde orbits (opposing their star's rotation), as this phenomenon suggests complex dynamical interactions not directly addressed by the model.

Which of These Exoplanet Characteristics Is MOST Difficult to Explain