Astronomy hw

We now know that the orbit of a stable planet around a star like the Sun is always in the shape of:

An ellipse

In what fundamental way did the work of Galileo differ from his predecessors who had thought about the sky?

Galileo used insturments and experiments to show him what nature was doing, instead of relying on pure logic

The scientist who formulated the three laws of planetary motion by analyzing the data on the precise location of planets in the sky was:

Johannes Kepler

When NASA and a group of astronomers sent up a spacecraft designed to find planets orbiting other stars, they named it after Kepler. Why was this an appropriate name?

Kepler figured out the rules of planetary motion, which planets in out solar system and planets elsewhere must obey

According to the geocentric view, everything in the heavens had to go around the Earth, which was the center of the universe. What objects did Galileo discover with his telescope that clearly didn't go around the Earth?

Moons around the planet Jupiter

The great astronomer of ancient times who summarized and improved a system of circles upon circles to explain complicated motions of the system in a book now called the Almagest is

Ptolemy

In Ptolemy's system, the planets orbit theEarth and not the Sun. How did the system explain the retrograde motion of planets like Jupiter

The planets moved on a small circle whose center, in turn, circled a point near the Earth

he 17th century astronomer who kept a roughly 20-year continuous record of the positions of the Sun, Moon, and planets was:

Tyhco Brahe

Suppose a person said to you "Einstein's theory of relativity is a theory so it must be correct"

While it could be correct, it is always possible that the next test could identify a flaw or a weakness

Suppose a person said to you "Einstein's theory of relativity is just a theory so it could be wrong" Which of the following statements would be the best response to that remark

While it could be wrong, scientists call a it a "theory" because it has held up under rigorous testing so it seems pretty unlikely that it is wrong

t or f An astronomical hypothesis is a piece of knowledge that every atronomer accepts

false

t or f The fact that we cannot see stellar parallax with our unaided eye could mean either that the Earth is not moving or that the stars are really far away

false

When Galileo pointed his "spyglass" (telescope) toward the night sky, he discovered that the planet Mars had four large moons.

false it was Jupiter

When a planet, in its orbit, is closer to the Sun, it:

moves faster than average

Which of the following is the primary flaw in the Copernican heliocentric model that hindered its predictive accuracy

orbits were perfectly circular

When a planet temporarily moves westward in the sky over the course of several weeks or months (instead of eastward as it typically does), we call it

retrograde motion

According to Kepler's laws, a typical comet will spend much more time in the part of its orbit far from the Sun and much less time in the part of its orbit close to the Sun

true

In his second law, Kepler discovered that a planet speeds up as it comes closer to the sun and slows down as it pulls away

true

Keplers third law relates a planet's orbital period to the semi major axis of the orbit

true

One way that Galileo demonstrated that the heliocentric was correct was to show that the phases of Venus visible through his telescope could only be explained if Venus was around the Sun

true

Scientific models and hypotheses can change as new experiments or observations are done, often with better equipment

true

We now know that the geocentric view of the universe is not correct

true

While ancient thinkers expected the motions of the planets to be circles, Kepler used Tycho Brahe's data to show that the planets moved around in Ellipses

true

The scientist who first devised experimental tests to demonstrate the validity of the heliocentric model of the solar system was

Galileo

The Renaissance astronomer who wrote the pioneering book that suggested the Earth probably orbits the Sun (instead of the other way around) was:

Copernicus

Which of the following was NOT done by Galileo Galilei?

Explaining retrograde motion with the heliocentric hypothesis

Kepler found out after much work that the orbit of each planet was a circle centered on the Sun

False

According to Kepler's third law, there is a relationship between the time a planet takes to revolve around the Sun and its

distance from the sun