Question

Which of the following provide evidence for the theory of planetary migration (select all answers that are correct). :

This discovery of gas giant planets in other systems in close orbits around their stars.

Neptune is more massive than Uranus.

The asteroid belt and the small size of Mars compared to Earth and Venus.

Jovian planets have many moons.

The amount of water on Earth and the relatively large size of its Moon.

The large metal composition of Mercury

Answer 1

Planetary migration take place when a planet or other body in orbit around a star interacts with a disk of gas or planetesimals, resulting in the alteration of its orbital parameters, especially its semi-major axis. Planetary migration is the most likely explanation for hot Jupiters: exoplanets with Jovian masses but orbits of only a few days. The generally accepted theory of planet formation from a protoplanetary disk predicts such planets cannot form so close to their stars, as there is insufficient mass at such small radii and the temperature is too high to allow the formation of rocky or icy planetesimals.
The migration of the outer planets is a scenario proposed to explain some of the orbital properties of the bodies in the Solar System's outermost regions.[41] Beyond Neptune, the Solar System continues into the Kuiper belt, the scattered disc, and the Oort cloud, three sparse populations of small icy bodies thought to be the points of origin for most observed comets. At their distance from the Sun, accretion was too slow to allow planets to form before the solar nebula dispersed, because the initial disc lacked enough mass density to consolidate into a planet

So correct options are
a)-This discovery of gas giant planets in other systems in close orbits around their stars

(C)-

The asteroid belt and the small size of Mars compared to Earth and Venus.

(D)-ovian planets have many moons