Astronomy Study Questions

Front

Describe geocentric and heliocentric models of the solar system.

Back

Geocentric: Earth is in the middle

Heliocentric: The sun is in the middle of the solar system

Front

Describe the solar system models of Aristotle, Aristarchus, Ptolemy, Copernicus and Kepler.

Back

Aristotle: The Earth is motionless in the center of the universe, and all other celestial objects orbit it in perfect circles.

Aristarchus: The earth orbits the sun like all the other planets.

Ptolemy: Geocentric like Artistotle's model, only with epicycles (mini-orbits)

Copernicus: Geocentric, remarkably similar to Aristarchus' model, only with actual evidence

Kepler: Geocentric with elliptical orbits instead of perfect circles

Front

Describe the contributions of Galileo to our knowledge of the solar system.

Back

Discovered:

1. Moons of Jupiter

2. Phases of Venus and Mercury

3. Mountains on the moon

4. That the Milky Way is made of stars

Front

Why was the geocentric model widely accepted for well over 1000 years?

Back

1. Parallax was not observable without modern technology.

2. The Earth doesn't obviously appear to be moving

3. It looks like the sun is going around the Earth, not the other way around.

Front

How did the geocentric model of Ptolemy account for the retrograde motion of some of the planets?

Back

He added epicycles

Front

How is parallax used to estimate the distance to some of the stars?

Back

If you know the angle of the motion of a star in six months, you can use the tangent of an angle to calculate the length of the "missing side" of the triangle that is formed in the sky (with points at Earth, sun and the star).

Front

Describe how the solar system was formed. Include how the earth ended up with a large moon.

Back

When the sun was in its protostar phase, it spun off a disc of gas and dust, which eventually cooled, clumped together, and formed the planets and other objects in our solar system.

Front

What causes the seasons on our planet?

Back

The earth's axis is tilted 23 degrees from a perpendicular position.

Front

What are the dates of the solstices and equinoxes?

Back

Winter solstice (in the north): Dec. 21

Spring Equininox: March 21

Summer Solstice: June 21

Fall Equinox: September 21

Front

Draw a complete, labeled diagram that shows the position of the earth’s axis during one complete revolution around the sun.

Back