P2 topic 12 formation of planetary systems

Question 1

In addition to the formation of impact craters, describe two further pieces of evidence
for accidental collisions in the history of the Solar System.

Answer 1

Any two from parent body:

The Moon (1)
Uranus or Venus (1)
Mercury (1)
Phobos (1)
Any two corresponding descriptions:
Formation of (the Moon) (1)
Axial tilts (1)
Substantial iron core (1)
Parallel grooves on its surface (1)

Question 2

State one effect of the solar wind.

Answer 2

Any one from:
Cometary tails (1)
Aurorae (1)
Geomagnetic storms (1)
Shape of Earth’s magnetosphere (1)

Question 3

Whether a planet or moon has an atmosphere depends on an interaction between two

opposing factors.
What are the names of the two opposing factors?

Answer 3

gravitational and thermal factors

Question 4

State what is mean by a frost line.

Answer 4

Dividing ‘line’ (between ices being able to
condense into ‘grains’ (cold enough) and not
being able to condense (too hot)) (1)

Question 5

Explain why the existence of a frost line plays a key role in the formation of gas
giants in planetary systems.

Answer 5

‘Inside’ the frost line, ices did not condense (1)
‘Outside’ frost line, rich in ices so large
planetary cores formed (1)
These had sufficient gravitational effects to ‘pull
in’ large amounts of hydrogen and helium /
gases forming large atmospheres (1)