The Universe
Theories
Units of Measurement
Geocentric Theory
Heliocentric Theory
Astronomical Unit (AU)
Light Year
The Solar System
The Sun
Small Solar Bodies
Comets
Asteroids
Satellites
Planets
Dwarf Planets
Movements
Inner Planets (Rocky)
Outer Planets (Gaseous)
Rotation
Revolution (orbit)
Jupiter
Saturn
Neptune
Uranus
Venus
Mercury
Earth
Mars
is Made up of
GALAXIES
Stars
Planetary Systems
Natural Satellites
The Moon
The Sun
The Solar System
The Milky Way
Types of Galaxies
Elliptical Galaxy
Irregular Galaxy
Spiral Galaxy
Irregular shape
Don't have structure
Some may started as spiral or elliptical galaxy but collision with other galaxy cause them to change shape.
Found in Galaxy Cluster
Usually Small ,but
can be very large
Roughly Oval shaped
And 3-D
May Have Supermassive Blake hole
at their center
Common Type of Galaxy
Large ,flat rotating disks of stars, gas and dust
New star forms in the arms of Spiral
A Supermassive black Hole may be at their Center.