Reference no: EM133296836
Questions
1. The Hubble tuning fork diagram for galaxies is useful because it
A. organizes galaxies according to their age and size.
B. provides an objective way to classify galaxies that does not vary between observers.
C. shows how galaxies change over time.
D. summarizes the different shapes galaxies can have.
2. An observed galaxy contains many stars on ordered, circular orbits.
An astronomer will most likely classify this galaxy as
A. a spiral galaxy.
B. an elliptical galaxy.
C. an active galactic nucleus.
D. a globular cluster.
3. Why did it take a long time to confirm the existence of galaxies outside of the Milky Way?
A. Galaxies are very far apart. Therefore, it took a long time to come across one in observations.
B. Observational tools needed to detect other galaxies were not available.
C. Other galaxies were difficult to observe because they were very faint.
D. It was difficult to measure distances to far away objects and confirm that they were outside of the Milky Way.