1. Forming Planets
CEA Saclay simulation

2. New Worlds How long does it take to make a solar system?
A. 1 million years.
B. 10 million years.
C. 100 million years.
D. 1 billion years.

3. Gases in Space
Supernova stars explode and create clouds of gas and dust.
The gas includes hydrogen, helium, nitrogen, oxygen, etc.
Crab Nebula, 1000 years old

4. Formation of the Sun
Stars are formed by a gas/dust cloud contracting due to gravity.
Orion Nebula, 1 million years old

5. Protoplanetary Disk Gases begin to swirl around the star.
Inward from gravity
Outward from heat
Angular momentum is conserved.
HR 4796A,
10 million years old

6. Collisions and Accretion
From 10 to 100 million years, dust begins to stick together.
This is called accretion, and is aided by gravity.
Solid accretion toward star
Gas accretion outward
Radio image of Epsilon Eridani,
500 million years old

7. Migration There is more gas and dust near the star for formation.
A planet moving outward can slow the spin of a star.
Conservation of angular momentum
Protoplanet 6 MJ, 2 million years old
Keck telescope, 2011

8. Frost Line The heat of a star melts minerals that are close.
Frozen “ices” dominate at greater distances.
U Hawaii