2. Stars
The visible stars you see at night are only some of
the stars in our galaxy.
Most stars seem to be single stars, but in actuality
they are mostly doubles and triples.
1/3 are doubles
¼ are singles
3. Constellations
Constellations are patterns of starts.
They may look like they are close together but really
they are extremely far apart.
We recognize 88 different constellations.
Named after gods, heroes or fierce animals.
4. Galaxies
The major components of the universe are
galaxies.
They are large groups of stars bound together by
gravitational attraction.
Made up of millions of stars, dust clouds and
gases.
Estimated 50 billion and 1 trillion galaxies in the
universe.
We live in the Milky Way Galaxies.
5. Types of Galaxies
Spiral Galaxy: has a nucleus or bright center
with flattened arms that spiral around the nucleus.
6. Types of Galaxies
Elliptical Galaxy: They are very bright centers and
do not have spiral arms. Have no young stars and
contain very little dust and gas.
7. Types of Galaxies
Irregular Galaxy: has no particular shape. They
are very small and faint. Very little gravitational
pull.
8. The Milky Way
Our galaxy
Spiral galaxy
Has a diameter of 100,000 light years
Our sun is about 30,000 light years from the center.
Revolves at a speed of 250km/s.
Takes 200 million years to make one revolution.
9. Formation of the Universe
The big bang theory- matter was all concentrated in
an extremely small volume
Occurred 12-15 billion years ago.
Galaxies are continuing to move outward.
10. Formation of the Universe
The big bang theory- matter was all concentrated in
an extremely small volume
Occurred 12-15 billion years ago.
Galaxies are continuing to move outward.