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apparent rotation of the celestial sphere about the Earth

They were too busy screaming This is Sparta!!! to research the real reason.

It is incompatible with a flat Earth.

The Sun really does revolve around the Earth. 

The apparent rotation of the celestial sphere about the Earth fooled them.

The stars are too far away for stellar parallax to be observable with the naked eye.

They did not believe that the gods would design the universe that way.

A constellation is a group of stars related through an ancient story.

A constellation is any random grouping of stars in the sky.

A constellation is a region in the sky as seen from Earth.

A constellation is a group of stars that are all located in about the same place in space.

the Sun’s daily path from east to west in our sky

the path the Sun appears to trace around the celestial sphere each year

a half-circle extending from your horizon due north, through your zenith, to your horizon due south

the path traced by the Moon’s shadow on Earth during a solar eclipse

The angular distance between those two bright stars in the sky is about 2 meters.

The angular distance between those two houses in the distance is 30 degrees.

You can use your outstretched hand against the sky to estimate angular sizes and angular distances.

The angular size of the Sun is about the same as that of the Moon.

1/27/2019 Homework 2 6/9

Part A – If we have a new moon today, when we will have the next full moon?


Retrograde Motion

Part A – Explain what planetary retrograde motion is. What does it look like? Why does it occur?



Part A – How would a star’s  parallax change as its distance from Earth increases?


The Seasons: What if Earth’s Axis Tilt Were Different?

Learning Goal:

To understand how seasons would be affected by a greater or smaller axis tilt.

Introduction. What would happen to our seasons if Earth’s axis tilt were different from its actual 23.5°? This activity will help you answer this question and will also help you understand seasons on planets that have axis tilts different from Earth’s. As you examine the diagrams in parts A and B, keep in mind that Earth is always rotating, even though the diagrams do not show this rotation because they are not animated.

Part A – Each of the following figures shows Earth with a different axis tilt. (Assume that Earth’s rotation period is unchanged.) Each also shows a person located in Florida (not to scale). Rank the figures based on how much time the person spends in daylight  during a 24 hour period, from most (Left) to least (Right).

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in about 6 months

in about a month

in about 2 weeks

in about 1 week

3785 Character(s) remaining

Essay answers are limited to about 500 words (3800 characters maximum, including spaces).

(none provided)

The parallax shift does not change; it is independent of the star’s distance from Earth.

The parallax shift increases as the star’s distance from Earth increases.

The parallax shift decreases as the star’s distance from Earth increases.

1/27/2019 Homework 2 7/9

Part B – The following figures are the same as those from Part A. This time, consider the seasonal differences that occur as Earth orbits the Sun with the different axis tilts. Rank the figures on the basis of the seasonal temperature differences you would expect between summer and winter, from the one with the most extreme seasonal differences (Left) to the one with the least extreme (Right). To rank items as equivalent, overlap them.

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