Astronomy Quiz 1.2

Why did astronomers have to keep adjusting Ptolemy’s model?

• Ptolemy’s original data were not translated accurately

• Something was fundamentally wrong with the model

• Measuring instruments improved constantly

• It didn’t take centrifugal force into account

What type of model of the universe did Copernicus’ religious beliefs push him to investigate?

• Earth-centered

• Gravity-centered

• Elliptical

• Sun-centered

What was the result of the tilting of the plane of Earth’s equator, according to Copernicus?

• Earth’s changing seasons

• Changes in gravitational pull

• Changes in Moon phases

• Sunspots

What was Copernicus able to calculate relatively accurately?

• The distance between Earth and the Moon

• The time required for Mercury to orbit the Sun

• The relative distances of planets from the Sun

• The distance from the Sun to the Earth

What did Copernicus believe was a planet’s perfect path around the Sun?

• An ellipse

• An epicycle

• A circle

• A slightly flattened circle

What is one incorrect assumption Copernicus made in his model?

• The Earth remains in a fixed location

• Planets move at a constant speed

• Stellar parallax could not exist

• His predictions about planets’ motion were accurate

What body or bodies orbited the Sun, according to Tycho Brahe?

• Earth only

• Not Earth but the other planets

• The Moon

• All the planets including Earth

What orbital shape did Kepler find best fit his data?

• Circle

• Oval

• Egg-shaped

• Ellipse

What did Kepler’s second law explain?

• The shape of a planet’s orbit as it moves around the Sun

• Gravity

• A planet’s speed as it moves around the Sun

• Solar energy

What happens to a planet’s speed as it moves around the Sun?

• It speeds up when it is closer to the Sun

• It slows down when it is closer to the Sun

• It remains the same throughout its orbit

• It speeds up and slows down several times