Midterm - Planetary Formation

Question 1

Accretionary heat

Answer 1

released by impacting material

Question 2

Radiogenic heat

Answer 2

released by decay of radioactive atoms

Question 3

Tidal heating

Answer 3

due to friction when a satellite is repeatedly flexed by the gravitational attraction of its primary

Question 4

Solar energy

Answer 4

produced by nuclear fusion in the star and transmitted to planets via radiation

Question 5

Core formation

Answer 5

released by molten iron migrating to the center of a planet

Question 6

What allows for movement in a protoplanet?

Answer 6

Accretionary and especially radiogenic heating increase the internal temperature,to a critical point where material is molten enough to allow movement. Dense iron-nickel, previously distributed throughout the body, migrates toward the center to form a core. The sinking iron-nickel globules release gravitational potential energy that increases the interior temperature of the protoplanet and further mobilizes iron segregation. This can lead to a runaway effect, resulting in rapid core formation

Question 7

What is differentiation

Answer 7

This heating and core formation results in planets and large asteroids that are segmented (or differentiated

Question 8

What does differentiation create + what materials are where?

Answer 8

Crust: lower density silicates
Mantle: moderate density silicates
Core: dense iron