CH 2: Copernican Revolution

The major axis for a particular planet is known. In order to determine the perihelion and the aphelion, what other information about the planet is needed?

Galileo Galilei was the first scientist to perform experiments in order to test his ideas. He was also the first astronomer to systematically observe the skies with a telescope. Galileo made four key observations that challenged the widely accepted philosophical beliefs on which the geocentric model was based, thus providing support for the heliocentric model. From the following list of observations, which are the key observations made by Galileo that challenged widespread philosophical beliefs about the solar system?

Johannes Kepler used decades of Tycho Brahe's observational data to formulate an accurate description of planetary motion. Kepler spent almost 30 years of his life trying to develop a simple description of planetary motion based on a heliocentric model that fit Tycho's data. What conclusion did Kepler eventually come to that revolutionized the heliocentric model of the solar system?

Astronomers have made many observations since the days of Galileo and Kepler to confirm that the Sun really is at the center of the solar system, and that the planets revolve around the Sun in elliptical orbits. Which observation(s) could you make today that Galileo and Kepler could not have made to confirm that the heliocentric model is correct?

In Ptolemy’s Earth-centered model for the solar system, Venus’s phase is never full as viewed from Earth because it always lies between Earth and the Sun. In reality, as Galileo first recognized, Venus is

Imagine that Venus is in its full phase today. If we could see it, at what time would the full Venus be highest in the sky?

When would a new Venus be highest in the sky?

When would you expect to see Venus high in the sky at midnight?

In Ptolemy’s Earth-centered model for the solar system, Venus always stays close to the Sun in the sky and, because it always stays between Earth and the Sun, its phases range only between new and crescent. The following statements are all true and were all observed by Galileo. Which one provides evidence that Venus orbits the Sun and not Earth?

A vocabulary in context exercise in which students match words to definitions describing elliptical planetary orbits, applying ideas from Kepler's Laws of Planetary Motion.

Earth is located at one focus of the Moon's orbit.

According to Kepler's second law, Jupiter will be traveling most slowly around the Sun when at aphelion.

Earth orbits in the shape of a/an ellipse around the Sun.

The mathematical form of Kepler's third law measures the period in years and the semimajor axis in astronomical units (AU)

According to Kepler's second law, Pluto will be traveling fastest around the Sun when at perihelion.

The extent to which Mars' orbit differs from a perfect circle is called its eccentricity.

Suppose you are in an elevator. As the elevator starts upward, its speed will increase. During this time when the elevator is moving upward with increasing speed, your weight will be __________.

Suppose you are in an elevator that is moving upward. As the elevator nears the floor at which you will get off, its speed slows down. During this time when the elevator is moving upward with decreasing speed, your weight will be __________.

As you found in Part A, your weight will be greater than normal when the elevator is moving upward with increasing speed. For what other motion would your weight also be greater than your normal weight?

If you are standing on a scale in an elevator, what exactly does the scale measure?

Planets near opposition

A major flaw in Copernicus's model was that it still had

What is a scientific theory?

Can a theory ever be proved to be absolutely true?

An accurate sketch of Jupiter's orbit around the Sun would show

An asteroid with an orbit lying entirely inside Earth's

If Earth's orbit around the Sun were twice as large as it is now, the orbit would take