Name ______

Chapter 2 Homework

1.Why does the moon appear larger when it rises than when it is high in the sky?

2.What does Kepler's third law state?

3.By how much are the paths of the planets on the sky tilted with respect to the celestial equator?

4.Why did Copernicus' heliocentric model fail to work as well as it might have to predict the positions of planets?

5.What were a couple ofthings that Tycho Braheproved (discovered) that became major contributions to astronomy?

6.Who was the first person to measure (calculate) the circumference of the Earth.

7.What is one of the methods used to date supernova remnants (the remains of exploded stars) today

8.Which objects passes through the zodiac?

9.How do stars move with respect to the celestial sphere?

10.What is retrograde motion?

11.What is the size of an object located at a distance of 1 km and that has angular size A = 2?

12.What was a crucial observation of Galileo in rejecting the geocentric system?

13.What model has the Sun as the center of the solar system.

14. What model has Mr. Vining as the center of the solar system (and the universe).

15.During retrograde motion, how does a planet move relative to the stars?

16.Who’s extensive records of planetary positions did Kepler use to discover the orbits of the planets?

17.What does Kepler's first law state?

18.What does Kepler's second law state?

19. Suppose you were an alien living on the fictitious warlike planet Myrmidon and you wanted to measure its size. The Sun is shining directly down a missile silo 1000 miles to your south, while at your location, the Sun is 36° from straight overhead. What is the circumference of Myrmidon? What is its radius?

20. Suppose a planet were found with an orbital period of 64 years. How might you estimate its distance from the Sun? If its orbit is circular, what is its radius?

21. Suppose you received a message from aliens living on a planet orbiting a star identical to our Sun. They say they live 4 times farther from their star than the Earth is from the Sun. What is the length of their year compared to ours?

22. A planet is discovered orbiting a nearby star once every 125 years. If the star is identical to the Sun, how could you find the planet's distance from its star? If the planet's orbit is a perfect circle, how far from the star is the planet in AUs?

23. Observations with the Hubble Space Telescope revealed a planet about 16 AU from a star whose mass is the same as our Sun's mass. How long does it take the planet to orbit the star?

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