WGU Astronomy

Claudius Ptolemy attempted to explain the motion of the planets mathematically by devising a small circle, the epicycle, rotating along the edge of a larger circle, the deferent. What was at the center of these circles?

• The Earth
• The Sun
• The Moon
• The Void

What is a key distinction between Kepler’s model of the universe compared to previous models?

• Kepler was the first to propose that orbits are not perfect circles.
• Kepler was the first to propose that the earth orbited around the Sun.
• Kepler was the first to propose epicycles as an explanation of retrograde orbits.
• Kepler was the first to propose that the universe is expanding.

Tags

NGSS.HS-ESS1-4

Which scientist is credited with developing the mathematical framework to accurately describe the force of gravity and the way forces behave in our universe?

• Issac Newton
• Johannes Kepler
• Tycho Brahe
• Hipparchus of Nicaea

Tags

NGSS.HS-PS2-4

Which scientist utilized precision mathematics to develop planetary laws of motion?

• Kepler
• Copernicus
• Erastothenes
• Galileo

Which scientist was unable to identify a parallax in his measurements of stellar positions and so was unable to support a heliocentric model for the Solar System?

• Tycho Brahe
• Galileo Galilei
• Johannes Kepler
• Isaac Newton

What did Ptolemy use to explain retrograde motion in his model?

• Epicycles and deferent
• Elliptical orbits
• A Sun-centered universe
• Solar parallax

What is one observation Galileo made that was used to support the heliocentric theory?

• Phases of Venus
• Aurora borealis
• Moon phases
• Supernovae

Which statement in Kepler’s first law proves planetary motion as a heliocentric model?

• Planetary motion shows elliptical orbits.
• Planetary motion is always at a constant speed.
• Planetary motion is explained as a line joining a planet and Sun, sweeping out equal areas during equal time intervals.
• Planetary motion is defined as the square of orbital period of a planet being proportional to the cube of the semi-major axis.

Tags

NGSS.HS-ESS1-4

Object A and Object B orbit the Sun. Object A is observed to orbit the Sun every 64.0 years. Object B is measured to be an average distance of 125.0 AU away from the Sun. Which statement is true?

• Object A is closer to the Sun than Object B.
• Object A is further from the Sun than Object B.
• Object A and Object B are at the same distance from the Sun.
• The distance between the Sun and Object A cannot be determined.

Tags

NGSS.HS-ESS1-4

Which comet broke up and bombarded Jupiter in 1994?

• Shoemaker-Levy 9
• Halley’s Comet
• Hale-Bopp
• Swift-Tuttle