The Hidden Lives of Galaxies - Answer Key for Activities
Answer Key for Activities
Activity #1 - How Big is the Universe1. What is the total size of the Milky Way Galaxy? 100,000 light years
2. The visible universe will be a sphere approximately 12 km in radius. Activity #2 — Identifying Galaxies
1.Titles will vary, but may be, e.g. "The Galaxy Types", or "Five Types of Galaxies"
| A. Spiral — galaxy with tightly wound spiral arms |
| B. Elliptical — slightly elliptical to nearly circular |
| C. Barred Spiral — spiral with a bright bar of gas through the center |
| D. Peculiar — fits none of the descriptions |
| E. Irregular — small, patchy, irregularly shaped galaxy |
2. Identify the types of the ten galaxies labeled on the Deep Survey Image.
| A. Irregular | F. Barred spiral |
| B. Spiral | G. Elliptical |
| C. Spiral | H. Spiral |
| D. Elliptical | I. Irregular (or Peculiar) |
| E. Barred spiral | J. Elliptical |
Assessment
Inferences that can be made from observing the Hubble Deep Survey Image should include that the objects are galaxies and not stars. These galaxies are of different sizes, shapes, brightnesses, distances, and color.
Activity #3 — Classifying Galaxies Using Hubble’s Fork DiagramGalaxy |
Scheme |
Classification |
Andromeda |
Spiral | Sb |
M84, NGC4374 |
Elliptical |
E1 |
NGC 2997 |
Spiral |
Sb |
NGC5383 |
Barred Spiral |
SBb |
Large Magellanic |
Irregular |
Ir |
NGC4622 |
Spiral |
Sb |
M83 |
Spiral |
Sc |
Centaurus A |
Peculiar |
P |
M59, NGC4621 |
Elliptical |
E5 |
NGC1365 |
Barred Spiral |
SBc |
Assessment
1. Examples of how to classify objects in everyday life may include organizing a CD collection, sorting clothes, organizing magazines.
2. An example of how classifying helps organize one’s life may be that an organized CD collection makes it easier to locate music by artist name or music type.
