A COMET'S TALE

Comets are small, fragile, irregularly shaped bodies composed of a mixture of non-volatile grains and frozen gases. They have highly elliptical orbits that bring them very close to the Sun and swing them deeply into space, often beyond the orbit of Pluto.

THE TASK

In this SpaceQuest  you will read a series of sections on the origin, characteristics, and history of comets, with accompanying animations.

THE PROCESS

Visit the links of each section of the site and answer the questions.

HISTORY AND EXPLORATION

1. The first section gives an overview of how people thought about comets before there were telescopes.

a.  How did people feel about comets? Give two distinct views from two different centuries.

b. Name three painters that depicted comets in their paintings.

c. What does the name 'comet' mean?

ORIGIN OF COMETS

1. Describe the formation of comets.

2. Are comets part of the solar system?

3. What is the Oort Cloud made of, and where is it located?

4. What is the difference between the Kuiper Belt and the Oort Cloud? 

5. Give three similarities and three differences between planets and comets.

CHARACTERISTICS

1. What happens to a comet when it gets near the sun?

2. Draw a sketch of a comet  and label all its parts.

3. Write a brief description of each part of a comet.

4. Comets are usually seen only in the night sky. How is it that we see the effect of the sun's light on a comet, after the sun has set?

4. A comet can lose hundreds, or even thousands of kilograms of material each second as it passes by the sun and forms a dust tail. Does this mean that comets could eventually disappear? What do you think, and why?

COMET ORBITS

1. In the word perihelion, "peri" means close. What do you think the "ap" in aphelion means? What is the meaning of "helios"?

2. What is the period of a comet?

3. Do you know another name for the earth's orbital period?

4. What is a long period comet?

5. How long can the period be for a long period comet?

6. How are short period comets different from long period comets?

KILLER COMETS

Scientists disagree about the extinction of the dinosaurs.

1. Summarize the main points of the "Extrinsic Catastrophist" hypothesis.

2. Summarize the main points of the " "Intrinsic Gradualist" hypothesis.

3. What are the main points that support recent evidence.

4. What is meant by an oblique angle?

COMETS, METEORS AND ASTEROIDS

1. What are the cahracteristics of:

a. A meteor?

b. A meteoroid?

b. A meteorite?

c. Meteor shower?

d. Asteroid?