Astronomy

Which scientist proposed a heliocentric universe in which the Sun, rather than the Earth, was the center?

• Tycho Brahe

• Claudius Plotemy

• Nicolaus Copernicus

• Isaac Newton

What was the significance of Galileo’s observations of the phases of Venus?

• Galileo showed that Venus was a planet.

• Galileo showed that moons orbit other planets.

• Galileo showed that the orbit of Venus is an ellipse.

• Galileo showed that Venus orbits the Sun.

Which Greek scientist was the first known proponent of heliocentricity?

• Aristarchus

• Aristotle

• Ptolemy

• Hipparchus

Which scientist promoted a geocentric view of the Solar System?

• Ptolemy

• Copernicus

• Galileo

• Newton

Which of Newton’s laws helps explain why a force is needed to keep the Moon orbiting around the Earth?

• Newton's 1st Law of Motion

• Newton's 2nd Law of Motion

• Newton's 1st Law of Planetary Motion

• Newton's 2nd Law of Planetary Motion

What was the greatest contribution made by Copernicus?

• The heliocentric universe theory

• The belief that the heavens are perfect and unchanging

• The accurate observations of planetary positions

• The discovery of mountains and craters on the Moon

Which of Kepler's Laws of Planetary Motion relate the period of a planet's orbit to its average distance from the Sun?

• Kepler's 1st law

• Kepler's 2nd Law

• Kepler's 3rd Law

• Kepler's Law of Gravity

Which correction did Kepler’s first law make to Copernicus’s model of planetary motion?

• The Sun is at a focal point of an elliptical orbit, rather than at the center.

• Planets orbit the Sun in a perfect circle to avoid crashing into each other.

• The orbital speed is constant.

• Linear and angular speed in an orbit are the same for all planets.

. Cepheid variable stars are “standard candles” of brightness. What did Edwin Hubble use them for?

• He used them to determine the distance from the Earth to the Sun.

• He used them to determine the distance from the Earth to the center of the Milky Way.

• He used them to determine the distance from the Earth to the Andromeda galaxy.

• He used them to determine the distance of a light year.

An astronomer is observing two star clusters. Each has a white dwarf star. The astronomer notes that one white dwarf appears nine times as bright as the other. What would explain this difference?

• The brighter white dwarf has three times the radius as the other.

• The brighter white dwarf has a much higher temperature than the other.

• The brighter white dwarf is closer to the Earth than the other

• The brighter white dwarf has a higher fusion rate than the other.