Transcript A SOLAR SYSTEM IS BORN

A SOLAR SYSTEM IS
BORN
Chapter 16 – 1
Part 1
The Solar Nebula
• Just like clouds in
the sky, there are
clouds in space.
• These clouds are
called nebulas.
• They are made
mostly hydrogen
and helium and
dust.
Gravity Pulls Matter Together
• The matter of a
nebula is held
together by gravity.
• There is a lot of
empty space
between the
particles in the
nebulas.
• So the gravity is
very weak.
Pressure Pushes Matter Apart
• Gravity causes the particles in a nebula
to be attracted to each other.
• As particles move closer together,
collisions cause pressure to increase and
particles are pushed apart.
• If the inward force of gravity is
balanced by outward pressure, the
nebula becomes stable.
Upsetting the Balance
• The balance can be upset if two nebulas
collide or if a nearby star explodes.
• As the matter collapses inward, the
temperature increases and stars begin
to form.
• This is a solar nebula.
• Our sun formed like
this.
How the Solar System Formed
• The solar nebula collapses
and begins to spin.
• The rotating cloud gets
hotter and denser in the
middle.
• The outer edges of the
disk begins to cool.
• Dust particles collide and
form larger particles.
From Planetesimals to Planets
• The collision of particles formed bodies
called planetesimals.
• Their size continues to increase because
gravity keeps pulling in material.
• All suns, planets and moons are a sphere.
• A sphere is that shape because all points
on the surface are an equal distance from
center.
THE END