Question

1) describe how temperature influenced what materials condensed from the nebular cloud.

2) compare and contrast the composition of the inner and outer planets

3) explain the frost line and the influence it has on the formation of planets (in any solar system).

4) explain why our solar system has rocky inner planets and gaseous outer planets and identify the most metal-rich planet in the solar system

5) explain the occurrence of Hot Jupiters

Answer 1

Solution:

1) During the early stage of evolution , soon after the completion of the cloud collapse , nebula is hot . The mass accretion rate from the nebula onto the star is high . The equilibrium condensation temperature of the Silicates and metal comprises 90 % (by mass) of the condensable solids.The temperature decreases away from the mid plane and away from the Sun. The accretion of gas onto the sun leads to the dissipation of energy . The nebula is heated internally due to this .

Condensation metals include Iron , Nickel and Aluminum . Most metals condense into solids at temperatures of 1000 - 1600 K . Metals made up <0.2% of the Nebular mass.

2) The Inner planets are Mercury , Venus ,Earth and Mars. They are all solid and rocky and similar to Earth . Inner Planets are also called Terrestrial Planets . Inner planets are warmer as these are closer to Sun .

Outer planets are called Jovian Planets and are mainly Gaseous in nature . Outer planets are colder as they are farther away from the Sun. All Outer planets have rings .

3) Frost line is also called the Snow line or Ice line . It is the radial position of condensation or evaporation front which varies over time . With reference to the formation of the planets, it is the distance in the Solar Nebula from the central protostar where it is very cold to where the volatile compounds like water , Ammonia , CO2 ,CO condense into solid ice grains.

4) The temperature of the early solar system explains the Terrestrial nature of the inner planets . As the gases coalesced to form the proto Sun the temperature in the inner SOlar system rose . The temperatures rose to about 2000 K , so only substance which have very high melting points remained solid . That is why the inner solar system planets are all rocky .

5) Planetary migration is responsible for the formation of hot Jupiters. These are formed in the outer regions and then migrate to the inner regions of the Solar system . It forms beyond the frost line , from rock , ice and gases due to core accretion method of planetary formation .