Part 2: Astronomy

Name: Answer Key Date: Science Period:

ANSWER KEY Page 11 Part 2: Astronomy

Earth’s Rotation

1. In which direction does Earth rotate? ______From west to east

2. What is Earth’s hourly rate of rotation? 15°/hour______

3. How often does Earth rotate once? ______One time each day (every 24 hours)

4. The diagrams below represent two pieces of evidence that Earth rotates. Identify the evidence represented by each diagram. Diagram A Diagram B

______Coriolis Effect ______Foucault Pendulum ___

5. Toward which direction do wind and water currents deflect towards in the Northern Hemisphere? To the right ______

6. Toward which direction do wind and water currents deflect towards in the ? To the left ______

7. The of trails was taken by an observer in New York State facing north.

a. Which star is in the middle of the diagram? ______Polaris

b. The is measured to have an angular distance of 120 degrees. How many hours did it take to create this photograph? 120° ÷ 15°/hour = 8 hours Page 12 ANSWER KEY Part 2: Astronomy

Seasons

The diagram shows Earth revolving around the Sun. Letters A, B, C, and D represent Earth’s location in its orbit on the first day of the four seasons. First, label the dates of A, B, C, and D on the diagram below. Use this information to help you fill in the table below. 3/21

6/21 12/21

9/23

Description Position Description Position 24 hours of darkness at March 21 A North Pole D 24 hours of darkness at December 21 D South Pole B 24 hours of daylight at North September 23 C Pole B 24 hours of daylight at June 21 B South Pole D Winter in N. Hemisphere D Earth is at aphelion B

Summer in N. Hemisphere B Earth is at perihelion D Sun is overhead at Spring in N. Hemisphere A Tropic of Capricorn D Sun is overhead at Fall in N. Hemisphere C Tropic of Cancer B Winter in S. Hemisphere B Sun is overhead at Equator A, C Earth has greatest orbital Summer in S. Hemisphere D velocity D Earth has the lowest orbital Spring in S. Hemisphere C velocity B Fall in S. Hemisphere A 9 hours of daylight in NY D

Earth is closest to Sun D 15 hours of daylight in NY B

Earth is farthest from Sun B 12 hours of daylight in NY A, C

ANSWER KEY Page 13 Part 2: Astronomy

Seasons

The diagram below represents the Earth on the first day of a season as viewed from space. The shaded area represents nighttime.

1. What is the date represented in the diagram above? ______12/21

2. What season is beginning on this date in New York State? ______Winter ______

3. What is the duration of insolation in New York State on this day? ______9 hours

4. What is receiving the most direct rays of insolation? ______23.5°S (Tropic of Capricorn)

5. In three months, how will the intensity of insolation change for New York? In three months (March 21), the intensity of insolation will increase.

6. In six months, how will the duration of insolation for New York compare to the date shown by the diagram above?

Over the next six months, the duration of insolation will increase.

7. The model of Earth provided below represents Earth in its orbit 6 months later. On the model shown: A. Draw the position of Earth’s axis and label the axis B. Label the North Pole C. Draw the position of Earth’s Equator and label the Equator.

Axis NP

Equator

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Eccentricity

The diagram below represents the orbital path of a planet around the Sun.

X Sun

1. Calculate the eccentricity of the ellipse above. Show all work. Round your answer to the nearest thousandth. e = d = 1.7 cm = 0.2535211 = 0.254

L 6.7 cm

2. How does the shape of the orbit above compare to the shape of the orbit of Mercury? ______

______Mercury’s orbit is less elliptical than the orbit above.

3. Describe the shape of Earth’s orbit. ______Slightly eccentric ellipse

4. How does the gravitational attraction between the planet and Sun change as the planet moves

farther from the Sun? ______As a planet gets farther from the Sun, the gravitational attraction decreases. ______

5. How does the orbital velocity change as a planet gets closer to the Sun? ______As a planet gets closer to the Sun, the orbital velocity increases (gets faster). ______

6. On the orbital path above, place an X where the planet’s fastest orbital speed will be.

7. As an ellipse gets more elliptical, what happens to the value of its orbit’s eccentricity? ______As an ellipse gets more elliptical, the value of the orbit’s eccentricity______increases (gets closer to 1).

ANSWER KEY Page 15 Part 2: Astronomy

Moon Phases

The diagram below represents the Moon in 8 positions in its orbit around the Earth.

Draw the Phase! 1 2 3 4

5 6 7 8

1. Draw the phase of the Moon, as seen from Earth, for each numbered position in the space above. 2. How long is one revolution of the Moon around Earth? ______27.3 days 3. How many days does it take for the Moon to complete one complete cycle of phases? _____29.5 days____ 4. What causes the phases of the Moon? ______Moon’s revolution around the ______Earth_____ 5. Which phase (name and number) causes a solar eclipse? ______New moon (1) ______6. Which phase (name and number) causes a lunar eclipse? ______Full moon (5) ____ 7. Why do we see the same side of the moon every day? ______The Moon’s period of revolution equals the Moon’s period of rotation. 8. Describe the height of high tide and low tide of spring tides. ______Highest high tide & lowest low tide 9. Which two phases (name and number) cause spring tides? ______New (1) & Full (5) ____ 10. Describe the height of high tide and low tide of neap tides. ______Lowest high tide & highest low tide st rd 11. Which two phases (name and number) cause neap tides? ______1 Quarter (3) &______3 Quarter (7) 12. Why does the Moon have more influence on the tides than the Sun? ______Moon is closer to Earth than Sun. 13. Approximately how much time is there between consecutive high tides? ______12 hours 26 min__ 14. Why are there so many more impact craters on the Moon than on Earth? ______Earth’s atmosphere has destroyed craters.

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New York State Celestial Sphere

The diagram below represents the path of the Sun on different three dates, A, B, and C, as viewed from New York State at 45°N. The position of the Sun is indicated by the circle on each path.

Polaris (45°)

1. Identify one possible date the Sun will travel across each path shown above. Explain your answer.

A: ______December 21. Sun rises SE and sets SW.

B: ______March 21/September 23. Sun rises due East and sets due West.

C: ______June 21. Sun rises NE and sets NW.

2. On each path of the Sun, draw two arrows to show the direction the Sun appears to move.

3. Draw and label the position of on the diagram.

4. State one city in New York State that this observer could be located. ______Massena

5. What is the name given to point D? ______Zenith

6. When is the Sun directly overhead in New York State? ______Never ______

7. What time of day is shown by the position of the Sun on each path? ______Noon (12 pm)

8. Which season has the greatest angle of insolation? ______Summer

9. Which season has the lowest angle of insolation? ______Winter

10. What happens to the length of a shadow from sunrise to noon? ______Gets shorter

11. What happens to the length of a shadow from noon to sunset? ______Gets longer______

12. Which season has the longest noontime shadow? ______Winter

13. Which season has the shortest noontime shadow? ______Summer

ANSWER KEY Page 17 Part 2: Astronomy

Celestial Spheres from Around the World

The diagrams below show the apparent path and solar noon positions of the Sun on specific dates at three different locations on Earth.

1. Identify the cause of the apparent daily motion of the Sun through the sky. ______Earth’s rotation

2. How many hours of daylight is the observer at location C experiencing on June 21? ______24 hours

3. What is the latitude of location C? Explain how you determined this using the diagram. ______North Pole – all directions are south______4. Explain how you know location A is at the equator. ______Sun is directly overhead______at noon on______equinox 5. How do you know location B is in the Northern Hemisphere? ______Sun is due South at noon each day

Celestial Spheres: Time & Shadows

Locations of the Sun along an apparent path for an observer in NYS on March 21 are shown on the diagram below. Determine the approximate time of day and shadow direction for each location of the Sun. Record your answers in the table below.

Letter Time Shadow Direction

A 9 am Northwest B 12 pm Due north

C 3 pm Northeast

D 6 pm Due east

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Our Solar System

The diagram below represents a model of our solar system.

1. Does this model represent the geocentric model or heliocentric model? Explain your answer. Heliocentric model because the Sun is in the center. ______

______

2. What is the age of our solar system (including our Sun & all planets)? ______4.6 billion years______

3. Which planets are terrestrial? ______Inner 4 – Mercury,______Venus, Earth,______Mars Small & rocky 4. What are the characteristics of these planets? ______

5. Which planets are Jovian? _Outer______4 – Jupiter,______Saturn,______Uranus,______Neptune

6. What are the characteristics of these planets? ______Large & gaseous______

7. Which planet is most similar in size to Earth? ______Venus ______

8. Which planet has a longer day than year? ______Venus ______

9. Which planet would float in water (if you had a container large enough)? ______Saturn

10. How many times larger is Jupiter than the Earth? ______11 times larger

11. Between which two planets is the Asteroid Belt located? ______Mars & Jupiter

12. Why does Venus have the highest surface temperatures, even though it is not the closest planet

Runaway greenhouse effect – Venus’ atmosphere is 95% CO2. This to the Sun? ______

______greenhouse gas allows short-wave visible sunlight to pass through,

______but traps long-wave infrared heat near surface.

13. Describe the eccentricity of comets. ______Comets have very elliptical orbits

ANSWER KEY Page 19 Part 2: Astronomy

Stars

Diagram A: The diagram below shows the Diagram B: The diagram below shows two possible constellation Orion which is visible in the sequences in the life cycles of , beginning with winter months in the Northern Hemisphere. their formation from nebular gas cloud in space.

1. Why can we see Orion in December, but not in June? ______Earth revolves around the Sun

2. Fill in the missing information in the chart below using the “Characteristics of Stars” chart. Star Name Temperature Color Luminosity Star Type Betelgeuse 3,300 K Orange 100,000 x Supergiant Procyon B 8,900 K White 0.0007 x White Dwarf Aldebaran 4,000 K Orange 700 x Giant Sirius 9,500 K White 30x Main Sequence

3. What is the process by which stars produce energy? ______Nuclear fusion 4. What is the “fuel” of the Sun? ______Hydrogen _____ 5. Which category does a majority of the stars fit into? ______Main sequence______6. Our Sun is classified in which group of stars? __Main______sequence ______7. In 5 billion years, our sun will reach its intermediate stage and become a ______Red giant . How will the temperature and luminosity change in this intermediate stage? ______Temperature will decrease and luminosity will increase. 8. What is the ultimate fate of our sun in the late stage? ______White______dwarf ______How will the temperature and luminosity change in this late stage? ______Temperature will increase and luminosity will decrease. 9. According to Diagram B, what factor determines the life-cycle path of a star? ______Mass or size 10. Which force is responsible for changing a nebula into a protostar? ______Gravity

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Deep Space & the Origins of Our Universe

Diagram A below represents a timeline of the big bang theory. Diagram B below shows spectral lines of hydrogen gas observed in a laboratory compared to spectral lines of hydrogen gas produced by a distant galaxy.

Diagram A Diagram B

1. How long ago did the Big Bang occur? ______13.7 billion years ago 2. State two pieces of evidence of that support the big bang theory. 1) ______Red shift of light from distant galaxies______2) ______Cosmic microwave background radiation 3. Astronomers viewing light from a distant galaxy observe a shift of spectral lines toward the red end of the visible spectrum. Describe the movement of this galaxy. ______A red shifted galaxy is moving away from the Earth. 4. Astronomers viewing light from a distant galaxy observe a shift of spectral lines toward the blue end of the visible spectrum. Describe the movement of this galaxy. ______A blue shifted galaxy is moving towards the Earth.______5. Describe the movement of the galaxy using Diagram B above. Explain your answer. ______This galaxy is moving away from Earth because it is red shifted. 6. What is a galaxy? ______Group of billions of stars 7. What is the name of the galaxy we live in? ______Milky Way ______8. What type of galaxy do we live in? ______Spiral shaped 9. How does the age of our universe compare to the age of our solar system? ______Our universe is much older than our solar system 10. List the following astronomical features, in order of relative size, from smallest to largest.

Saturn , Milky Way Galaxy, Sun, Universe, Our solar system, Earth’s Moon

Earth’s Moon, Saturn, Sun, Our Solar System, Milky Way Galaxy, Universe

ANSWER KEY Page 21 Part 2: Astronomy

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