Name:______

CHAPTER 19 REVIEW

DIRECTIONS:Answer the following questions using complete sentences.

  1. Describe how Copernicus’s model of the solar system differs from Aristotle’s original model of the solar system. Copernicus’s model had the sun at the center of the solar system (heliocentric). Aristotle had the earth at the center of the solar system (geocentric).
  1. Describe how today’s model of the solar system differs from that of Copernicus.

The planets travel in ellipses or ovals, not perfect circles.

  1. Explain how the nebular model accounts for the differences between the inner and outer planets. The fact that terrestrial planets formed closer to the sun meant that all their extra stellar matter and gases were burned away.
  1. Explain how the fact that most planets orbit in the same direction supports the nebular model. The cloud of rotating dust spun faster and flattened out. Objects that form out of a disk will lie in the same plane, have almost circular orbits , and will orbit in the same direction.
  1. Explain why the inner planets are known as terrestrial planets. It is because they are made of rocky material similar to earth.
  1. Describe how specific characteristics of Earth permit it to sustain life. The existence of water, hydrosphere allows for life to exist. The atmosphere that surrounds our planet protects us from all sorts of meteor impacts.
  1. List three characteristics of gas giants. They are all large. They have no definite solid surface. They all have rings.
  1. Identify the planet that fits each description.

____Jupiter______a. largest planet in the solar system

____Venus______b. known for its runaway greenhouse effect

____Saturn______c. has the most extensive ring system

____Earth______d. the most habitable planet

____Uranus______e. tilted over on its side

____Neptune______f. first planet to be discovered using observed

gravitational anomalies

___Mercury______g. closest planet to the sun

__Mars____________h. has the largest volcanoes

  1. Why are all the planets approximately the same age? How old are they?

It is because they are believed to have formed at the same time. 4.6 Billion years old.

  1. What divides the inner and outer planets? An asteroid belt divides the inner and outer planets.
  1. Why is Pluto no longer considered to be a planet? It is now believed to be an asteroid that belongs to the Kuiper belt.
  1. Why is the surface of Venus hotter than the surface of Mercury? It is due to the runaway greenhouse effect. The thick clouds of carbon dioxide hold in the heat from the volcanic eruptions on the planet.
  1. What is meant by the term hydrosphere? It refers to all of the water that is on the surface of the earth.
  1. Contrast the terms geocentric and heliocentric. Make sure that you define the terms in your answer. Geocentric – earth centered

Heliocentric – sun centered.

  1. What is the difference between the terms rotation and revolution? To what length of time does each belong?Rotation – spinning on an axis – day.

Revolution – orbiting the sun - year

  1. Why is gravity so important when talking about space. Gravity holds the planet in their orbit.