Transcript Astronomy Unit 1 Review

Review Day
Drill: What celestial object is described as
a “dirty snowball” and why?
Objective: SWBAT review concepts
presented in the first unit of Astronomy in
order to prepare for Thursday’s test.
HW: Test Thursday
Our Solar System
 My
 Very
 Energetic
 Mother
 Just
 Served
 Us
 Nachos
 Mercury
 Venus
 Earth
 Mars
 Jupiter
 Saturn
 Uranus
 Neptune
Astronomy Unit 1 Review
History of Our Solar System
Ptolemy: Geocentric model placed Earth at the
center of the solar system. Planets orbited in
little circles on a bigger circle.
Copernicus: Heliocentric model placed the sun
in the center but planets orbited in perfect
circles.
Kepler: Created the modern day model of the
solar system. Heliocentric with elliptical orbits.
Orbits
 Planets orbit the sun in an elliptical shape.
 A combination of Inertia and Gravity cause the
shape.
 Inertia: The force of a moving object to resist
change speed or direction.
 Gravity: Attraction between two objects affected
by 2 things.
Distance: the closer you are the stronger the force.
Mass (weight): the heavier the object the greater the
force.
Nebular Theory
The solar system formed from a large
cloud of gas and dust called a NEBULA
A concentration of mass in the nebula
created an imbalance and caused the
cloud to collapse and spin.
As more matter moved to the center the
material began to spin more rapidly
creating a bulge in the center and a
flattened disk.
Nebular Theory con’t
Material in the disk separated by
density/mass.
Heavier materials were pulled close to the
sun forming the inner planets.
Lighter materials gravitated to out to form
the outer planets.
Inner and Outer Planets
 Inner planets are:
Terrestrial: made of
rock and metal
Small
Hot
Orbit close together
Closer to the sun
 Outer planets are:
Gas: Mostly Hydrogen.
Large
Cold
Orbit far apart
Farther from the sun
Comets and Asteroids
 Comets are:
“Dirty snowballs” made
of ice, gas, dust, and
rock.
Have a head called the
nucleus and a halo
called the coma.
Have a tail.
Found in the Oort cloud
and Kuiper belt.
 Asteroids are:
Made of rock and
metals.
Mostly found in the
asteroid belt between
Mars and Jupiter.
The Breakdown of Meteoroids
Meteoroids: Broken pieces of Asteroids
and Comets in space.
Meteors: Meteoroids that enter the Earth’s
atmosphere causing streaks.
Meteorites: A meteoroid that passes
through the Earth’s atmosphere and
reaches the Earth’s surface.