GALILEO’S DISCOVERIES
What instrument did Galileo use to make his astronomical discoveries?
Telescope
What does the Ptolemaic model claim is at the center of the universe?
Earth
What shape are planetary orbits according to Kepler’s First Law?
Elliptical
Who proposed the first geocentric model using celestial spheres?
Eudoxus
What causes day and night on Earth?
Earth’s rotation on its axis
What feature of the Moon did Galileo observe that challenged the idea of perfect heavens?
Mountains and craters
Which observation showed that not everything revolves around Earth?
A. moon's craters
B. Phases of Venus
C. Moons of Jupiter
C. Moons of Jupiter
According to Kepler’s Second Law, planets move fastest when they are…
Closest to the Sun
How many spheres are in Aristotle’s final model?
56 spheres
What do we call a group of stars that forms a pattern in the sky?
Constellation
What did Galileo discover orbiting Jupiter?
Moons (four major moons)
Why were the phases of Venus important?
They showed Venus orbits the Sun
Which law relates orbital period and distance from the Sun?
Kepler’s Third Law
Which model of the universe places Earth at the center?
Geocentric model
Which planet is known as Earth’s “twin” because of its similar size?
Venus
What solar feature showed that the Sun is not perfect and unchanging?
Sunspots
True or False: The geocentric model could explain all of Galileo’s observations.
False
Mars has an average orbital distance of
a2=2.28×1011m.
Earth’s orbital distance is
a1=1.496×1011m and T1=1 year.
Find the orbital period of Mars.
1.88 years
In which model do planets move in circular paths using epicycles?
Ptolemaic model
Which planet in our solar system has the most visible rings?
Saturn
Why did the discovery of supernovas weaken ancient beliefs about the universe?
It showed the universe changes over time and is not permanent
Explain in one sentence why Galileo’s observations weakened the geocentric model.
They showed that celestial bodies orbit objects other than Earth and that the heavens are imperfect
Earth has an orbital period T1=1 year and an average distance from the Sun
a1=1.496×1011m.
An unknown planet has an orbital period of 23 years.
Find its average orbital distance a2.
1.209x1012m or 1.21x1012m
Why was the heliocentric model eventually accepted over the geocentric model?
It better explained observations such as planetary motion, phases of Venus, and worked with Kepler’s laws
How many planets are there in our solar system?
8