Transcript Formation of Our Solar System Formation of Our

Formation of Our Solar System
Formation of Our Solar System
• How do we know?
–
–
–
–
Shape of our solar system
Differences among the planets
Oldest planetary surfaces
Asteroids, meteorites, and comets.
Formation of Our Solar System
A Collapsing Interstellar Cloud
• Interstellar Clouds:
– Stars and planets
form from clouds of
gas and dust.
• The interstellar clouds
are made mostly of:
– hydrogen and
helium
Formation of Our Solar System
A Collapsing Interstellar Cloud
• As a result of gravity…
interstellar gas starts to
condense.
Formation of Our Solar System
A Collapsing Interstellar Cloud
– The collapse
starts slow, then
accelerates
– Cloud becomes
much denser at
its center.
Formation of Our Solar System
Sun and Planet Formation
• The Solar Nebula:
– A rotating disk of dust and gas.
– The center becomes the Sun.
Formation of Our Solar System
Sun and Planet Formation
• As the disk began to cool, different elements and
compounds were able to condense depending
on their distance from the Sun
– determined compositions of the forming
planets.
Hotter
Cooler
Formation of Our Solar System
Sun and Planet Formation
Formation of Our Solar System
Sun and Planet Formation
The Growth of Objects
– Planetesimals : formed as smaller
particles collided and stuck together.
Formation of Our Solar System
Asteroids
Pieces of Asteroids
– As the asteroids orbit, they occasionally collide and
break into fragments.
• A meteoroid is a asteroid fragment or other material
that enters Earth’s atmosphere.
• A meteor is the streak of light produced when a
meteoroid burns up in Earth’s atmosphere.
• A meteorite is part of a meteoroid, that does not
completely burn up, that collides with the ground.
Formation of Our Solar System
Comets
Periodic Comets
– Meteor showers occur when Earth intersects a
cometary orbit and numerous particles from the comet
burn up upon entering Earth’s upper atmosphere.
– “Shooting stars”
End of Custom Shows
This slide is intentionally blank.