chapter 21 geol
The first modern astronomer to propose a Sun-centered universe was ________.
Copernicus
What major change did Copernicus make to the Ptolemaic system? Why was this change philosophically different?
Copernicus replaced Earth with the Sun in the middle of the planets' orbits, changing the geocentric view to a heliocentric view.
Which of the following statements best describes a geocentric view of the universe?
Earth is a motionless sphere at the center of the universe and the Sun, the Moon, and the planets orbit it.
In the Ptolemaic (Greek) model of the universe, ________.
Earth was in the center of the universe
The first scientist to use a telescope for astronomical purposes was ________.
Galileo
This scientist was the first to use the telescope in astronomy.
Galileo
________ discovered Jupiter's four largest moons.
Galileo
Earth is closest to the Sun in ________.
January
Three laws of planetary motion were discovered by ________.
Johannes Kepler
Which astronomer developed the three laws of planetary motion?
Kepler
________ discovered the three laws of planetary motion.
Kepler
Using the telescope, Galileo discovered that the planet ________ had polar ice caps not unlike those on Earth.
Mars
The first modern astronomer to propose a Sun-centered universe was ________.
Nicolaus Copernicus
Which of the three primary motions of Earth describes how the axial tilt of the planet slowly changes direction every 26,000 years?
Precession
What are the two primary motions of Earth?
Rotation and revolution
This scientist determined the nature of the forces that kept the planets in their orbits.
Sir Isaac Newton
Which of these men formulated the Law of Universal Gravitation?
Sir Isaac Newton
What did Galileo discover about the Moon?
That the Moon's surface has topography
The concept that Earth was a sphere was established around the time of ________.
The Ancient Greeks
The concept that Earth maintained a circular orbit around the Sun was suggested during the time of ________.
The Renaissance
What did Eratosthenes use to calculate Earth's circumference?
The angle of the noonday Sun in two locations Submit
Why did the ancients believe that celestial objects had some influence over their lives?
They noticed that season changes and floods correlated with the positions of celestial bodies in the sky.
Which position marks the location of a waxing crescent moon?
a
When Earth is the farthest from the Sun, it is said to be in the ________ position.
aphelion
The average distance from Earth to the Sun is called the ________ unit.
astronomical
In the Ptolemaic (Greek) model of the universe, the stars are attached to the ________.
celestial sphere
The earliest astronomical records appear to have been made by the ancient Chinese, Egyptians, and Babylonians in order to ________.
determine when to plant crops or hunt animals based on seasonal changes
One of the discoveries which led to the modern view of the solar system was that the orbits of the planets are ________.
ellipses
Which phase of the Moon is visible in this figure?
gibbous moon
The cycle of phases of the Moon is the basis for our ________.
month
A total eclipse of the Sun is only possible at ________.
new Moon
The two primary motions of Earth are ________ and ________.
rotation; revolution
According to the Ptolemaic (Greek) model of the universe, how many "heavenly" bodies could be observed wandering along the background of stars?
seven
When the Moon is going through its phases, these phases are created by the casting of a shadow. Which celestial body's shadow results in the different phases of the Moon?
the Moon
Galileo observed several features using the telescope. Which one of the following did he not discover?
the two moons of Mars
A _______ moon is when the Moon is moving into a position where observers on Earth can see more of the sunlit face.
waxing
