Lesson 1
Definition of parallax
Definition of phase
Chang in the sunlit area of one celestial body as seen from another celestial body
True or False:
Earth does not change its position in space as it orbits around the sun
False
What are galaxies measured in?
Light years
Why do stars change position year around?
Earth's axis and rotation. Stars follow seasonal changes.
What is the difference between a new moon phase and full moon phase
New moon: The moon is dark and between Earth and the Sun
Full moon: Earth is between moon and Sun
What does the Nebular theory suggest?
It suggests the Solar System is formed from gas and dust orbiting the Sun which clumped up together to form the planets.
Definition of globular clusters
What did Copernicus' heliocentric model propose?
It explained retrograde motion. Meaning planets orbit in an elliptical shape versus a circular path.
Why can solar eclipses be observed only on certain parts of Earth?
1. The moon is smaller than Earth
2. Half of Earth is facing away from the sun and cannot see the moon's shadow
3. Sunlight in areas outside of the umbra and penumbra is not blocked by the moon
Similarities: Both formed from gas and dust particles
Differences: The large mass of the sun and gravitational attraction between the planets and sun kept the planets in orbit around the sun
List 4 types of galaxy formations
1. Elliptical
2. Spiral
3. Barred spiral
4. Irregular
Which observations supported Aristotle's geocentric model? Provide at least 2
1. Sun, moon, and stars orbit in a circular path
2. Planet does not feel like its moving
3. Some planets cross between Sun and Earth
4. Some planets appear to pass behind the Sun.
What is the difference between a solar and lunar eclipse?
Solar eclipse: Moon casts a shadow on Earth
Lunar eclipse: Earth casts a shadow on the moon
Describe Laplace's Hypothesis of solar system formation. (5 steps)
1. Slow rotating cloud of gas and dust
2. Cloud begins to condense--> spin faster
3. Cloud flattens into a disk
4. Materials in ring collide and clump together
5. Forming planets and solar system
If the Milky Way is 100,000 light-years and the solar system is 1.9 light years, what is the scale ratio of the size of the solar system to the galaxy?
a. 50,000:1
b. 1:50,000
c. 50,000:2
d. 1:100,000