Formation of the Solar System
 This is a picture of the
Eagle Nebula taken by
the Hubble Telescope
in 1995.
 A nebula is a cloud of
gas and dust in space.
Image source: http://library.thinkquest.org/3645/universe.html
It all starts with A Collapsing
Interstellar Cloud
 These nebulas contain
hydrogen, helium, small
amounts of other
elements and dust.
 Where did that nebular
gas and dust come
from?
The Cloud Starts Collapsing

Gravity slowly pulls
the matter in the
cloud together until it
is concentrated
enough to form stars
and possibly planets.
What do you think is
forming here?
Concentrated mini-
chunks are
called________.
The Collapse Accelerates
•At first, the collapse
of the cloud is slow,
but as it speeds up,
the cloud becomes
denser at the center.
•What is forming in
the center of this
cloud?
•The cloud eventually
becomes flattened.
Image Source: http://www.centauri-dreams.org/wp-content/uploads/2006/02/counterrotate.single.jpg
Matter Condenses and Our Solar System
Was Born!
•The Sun formed
when it became hot
enough to fuse
hydrogen into
helium- this process
is called nuclear
fusion.
•The rotating disk
and planetesimals
surrounding the
young Sun became
our solar system.
•How and why did
the rotating “chunks”
become rounded,
spherical planets?
Image Source: http://jcconwell.files.wordpress.com/2008/10/solar-system-formation-early-1.jpg
So How Were the Different Planets
Formed?
•While the solar system
was forming, the
temperature
throughout the rotating
disk varied.
•The space near the Sun
was warm, while the
outer edge of the
rotating disk was
cooler.
•As a result, the inner
and outer planets were
formed from different
elements and gases in
different ways.
Image Source: http://www.nasa.gov/images/content/149759main_CarbonDiskMacLG.jpg
Steps of the Formation of the Solar
System
 1. There was a nebula of gas and dust.
 2. The nebula starts collapsing and gravity pulls




matter into the center of the cloud.
3. The collapse speeds up, and the cloud becomes
denser at the center.
4. The cloud flattens into a disk.
5. The disk starts to rotate.
6. A star forms from the dense matter in the center,
and the remaining matter forms planets as they
orbit the new star.
How would you illustrate this
process?
Image Source: http://shayol.bartol.udel.edu/~rhdt/diploma/lecture_11/solar-system.jpg