M
o
d
ule
4:
F
orm
a
tion of
P
l
a
n
e
t
s
PLANETARY FORMATION
1. Protoplanetary disk formation
-contains the rotating disk
of gas and dust.
2. Dust grain growth
- dust grain growth collide
and stick together due to
Van der Waals forces
forming larger particles.
3. Planetesimals formation
- larger dust aggregates
accumulate and form
larger objects
- continues to grow through
collisions and gravitational
interaction.
4. Protoplanetary cores
- massive planetesimals
attract significant amount of
gas from the protoplanetary
disk.
- building blocks of gas
giants planets
5. Terrestrial planet formation
- planetesimals collide and
merge in the inner regions of
protoplanetary disk.
- closer to the sun.
6. Clearing the disk
- protoplanets interact with
surrounding gas which either
accrete more materials or
clear out their paths
7. Stabilization and Evolution
- planets stabilize in their
orbits, and the protoplanetary
disk gradually dissipates.
8. Mature Planetary System
- protoplanetary disk is gone
and planets are in stable
orbits around the sun.
HOW PLANETS FORM
- Small objects in space coalesce and
form planet precursors called
PLANETESIMALS
- Planetesimals gather together due to
common gravity and form a Planet
REVOLUTION: 88 DAYS/ YEAR
TERRESTRIAL PLANETS
- Made of rocky material
- Solid surface
- No ring systems
- Few moons
- Relatively small
MERCURY
- known as a shrinking planet
because its iron core is slowly
cooling causing it to affect the
planet’s overall size to decrease.
- does not contain an atmosphere,
just a thin layer of exosphere
VENUS
Maxwell Montes
- volcano in venus that is almost as
high as mt. everest
- Rain in Venus is made up of Sulfuric
Acid (H2SO4)
