Exploring the Heavens: all
Chapter 1:  1.1,1.2
Chapter 2:  2.1,2.2,2.3
Chapter 3:  all

Topics for test 1

• Using your calculator / Unit Conversions

• General View of the Sky

• History of Astronomy

• Reason for the Seasons (Where is the Sun?)

• Phases of the Moon and Eclipses

• Parallax:  angle = baseline/distance

• Electromagnetic Spectrum:  wavelength x frequency = velocity

• Telescopes

• light gathering

• magnification

• resolution

• Kepler
• Newton

Answers are at the end of each section, so scroll down carefully if you don't want to see them right away.

In addition to the questions, you should know the speed of light, and how to calculate the distance of an object if you know your baseline and the parallax angle between your two observing locations.

• Using your calculator / Unit Conversions

how many minutes is 3.50°                (answer 210')

how many degrees is 7.00'               (answer .117°)

how many minutes is 5.30"                 (answer 0.0883' = 8.83x10-2')

how many degrees is 5.30"              (answer 1.47x10-3°; this one requires 2 steps)

• General View of the Sky (6 questions)

1) Durango’s latitude is +37.275° N. What is the southernmost Declination observable from Durango?

A) 0°

B) 37.275° S

C) 52.725° S

2) The angle that the North Star (Polaris) makes with the horizon (its’ height above the horizon) changes noticeably

A) as hours go by during the night

B) as months go by during the year

C) as you change latitude on Earth

D) as you change longitude on Earth

3) About how many stars can you see at one time from Durango with your naked eye?

A) 800

B) 4000

C) 20,000

D) 100,000

E) 1,000,000

4) About how many constellations can you see at one time?

A) 22

B) 44

C) 88

D) 144

5) Which coordinate is measured in degrees north and south of the equator?

A) declination

B) latitude

C) right ascension

D) longitude

E) Both A and B are correct.

6) From the horizon to the observer's zenith is an angle of:

A) 23.5 degrees for observers at the Tropics of Cancer and Capricorn.

B) 30 degrees for observers in north Florida, at a latitude of 30 degrees north.

C) 47 degrees over the course of the entire year.

D) 57 degrees for everyone on the earth.

E) 90 degrees for everyone on the earth.

C C B B E   E

• Science/History of Astronomy (4 questions)

1) Is it possible to prove or disprove a scientific theory?

A) Yes prove, yes disprove

B) Yes prove, no disprove

C) No prove, yes disprove

D) No prove, no disprove

2) In Ptolemy's geocentric model, the retrograde motion occurs when the planet is closest to us, on the inside portion of the:

A) ellipse

B) ecliptic

C) equant

D) deferent

E) epicycle.

3) A fatal flaw with Ptolemy's model is its inability to predict the observed phases of:

A) Jupiter and Saturn

B) the Sun during an eclipse.

C) the Moon in its monthly cycle.

D) Mercury and Venus.

E) Mars and Jupiter.

4) Which of these was NOT a telescopic discovery of Galileo?

A) the craters and mare of the Moon

B) the phases of Venus

C) sunspots and the rotation of the Sun

D) the four largest moons of Jupiter

E) the rings of Saturn

C E D E

• Reason for the Seasons (Where is the Sun?) (7 questions)

1) Why is it cold at the North Pole, even during northern hemisphere summer?

A) Because the "pole" itself doesn’t point very close to the direction of the Sun

B) Because there are fewer daylight hours at the pole than at lower latitudes (e.g., Durango)

C) Because of the high altitude at the pole

D) Because the pole is further away from the Sun than lower latitudes are (e.g., Durango)

2) Observing from a latitude of 25° North

A) The star Polaris appears about 65° above the horizon.

B) The celestial equator has a maximum height of 65° above the horizon.

C) The star Polaris appears about 25° north of the zenith point.

D) The celestial equator has a maximum height of 25° above the horizon.

3) Northern spring (March 21 to June 21) and autumn (Sept 21 to Dec 21) are the hottest seasons of the year at

A) Nowhere.

B) The tropic of cancer.

C) The tropic of capricorn.

D) The equator.

4) A sidereal day on Earth is:

A) Exactly 24 hours long.

B) About four minutes shorter than a solar day.

C) About four minutes longer than a solar day.

D) The time between full moons.

5) In Paris, France (50 degrees north latitude), what is the longest day of the year?

A) March 21

B) June 21

C) September 21

D) December 21

6) Where along the horizon does the Sun rise on June 21 in Sydney, Australia?

A) North of east

B) Due east

C) South of east

D) Can’t tell with information given

7) You are in Paris, France (50 degrees north latitude), on June 21.  What is the highest angle above the horizon that the Sun achieves?

A) 16.5° above the Southern horizon

B) 26.5° above the Southern horizon

C) 63.5° above the Southern horizon

D) 73.5° above the Southern horizon

A B D B B    A C

• Phases of the Moon and Eclipses (6 questions)

1) Which is correct?

A) The new moon rises at noon.

B) The first quarter moon rises at noon.

C) The full moon rises at noon.

D) The third quarter moon rises at noon.

2) On December 21, in Durango, if there is a full moon, where does it rise?

A) Due east

B) Almost due east (within 5 degrees)

C) South of east (by more than 5 degrees)

D) North of east (by more than 5 degrees)

3) Assume that the Sun rises at 6:00 A.M. What time does the third quarter Moon rise?

A) 9:00 A.M.

B) 12:00 noon

C) 9:00 P.M.

D) 12:00 midnight

4) If new Moon fell on March 2nd, what is the Moon's phase on March 14th?

A) waxing gibbous

B) waning crescent

C) full

D) first quarter

E) waxing crescent

5) If the Moon appears half lit, and is almost overhead about 6:00 AM, its phase is:

A) third quarter.

B) first quarter.

C) waxing crescent.

D) waning crescent.

E) full.

6) What conditions are needed to produce a total lunar eclipse?

A) full Moon on the equator at perigee

B) new Moon on equator at apogee

C) new Moon on ecliptic at perigee

D) any time the Moon crosses the ecliptic, the path of eclipses

E) full Moon on the ecliptic

B D D A A   E

• Parallax:  angle = baseline/distance (4 questions)

1) Star A has a parallax shift of 0.4 arc seconds.  Star B has a parallax shift of 0.6 arc seconds

A) B is 1.5 times as far away as A

B) Star A is at a distance of 4 parsecs (pc)

C) Star B is at a distance of 1.66 parsecs (pc)

D) Star A is 0.4 times as far away as B

2) The parallax angle becomes:

A) larger as the distance to the object increases.

B) larger as the separation between the two observing sites increases.

C) smaller as the distance to the object increases

D) Both A and B are correct.

E) Both B and C are correct.

3) Star A has a parallax shift of 0.3 arc seconds.  Star B has a parallax shift of 0.9 arc seconds.

A) Star B is three times as far as star A

B) Star A is at a distance of 1.5 pc

C) Star B is at a distance of 9 pc

D) Star B is three times closer than star A

4) You observe a classmate walking in the distance.  He appears to subtend a vertical angle of 0.017 radians.  You know that he is 1.7 meters tall.  How far away is he?

A) 10 m

B) 100 cm

C) 100 m

D) 1 km

C E D C

• Electromagnetic Spectrum:  wavelength x frequency = velocity (4 questions)

1) Which is correct

A) wavelength / velocity = frequency

B) wavelength / velocity = period

C) wavelength * frequency = period

D) wavelength * velocity = frequency

2) The speed of light in a vacuum is written as:

A) v = 186,000 miles per hour.

B) h = E/c.

C) v = 768 km/hour.

D) not given

E) c = 300,000 km/sec.

3) The period of a wave in a large crowd at a football game is 3.0 seconds.  The wavelength of this wave is 45 meters.  The speed of the wave is:

A) 1.5 m/s

B) 45 m/s

C) 3x105 km/s

D) 15 m/s

E) cannot be determined

4) Which list is in the correct order of electromagnetic radiation wavelength, going from shortest to longest?

B) gamma, x-ray, ultraviolet, visible

E) red, violet, blue, green

B E D B

• Telescopes    (6 questions)

• light gathering

• magnification

• resolution

1) A 5 meter telescope

A) gathers 5 times as much light as a 1 m telescope

B) gathers 1/2 as much light as a 10 m telescope

C) gathers 4 times as much light as a 2.5 m telescope

D) gathers 5/2 as much light as a 2 m telescope

2) The resolving power of a telescope is

A) Its ability to see very faint objects

B) Its ability to distinguish two adjacent object close together in the sky

C) Its ability to make distant objects appear much closer to us

D) Its ability to separate light into its component colors for analysis

E) Its ability to focus more than just visible light for imaging

3) What is the primary purpose of a telescope?

A) to magnify distant objects

B) to separate light into its component wavelengths

C) to measure the brightness of stars very accurately

D) to collect a large amount of light and bring it into focus

E) to make distant objects appear nearby

4) The design of modern x-ray telescopes depends on:

B) the prime focus design, with mirrors made of iron

C) grazing incidence optics

D) achromatic lenses to keep the x-rays in focus

5) A telescope has an 8 inch diameter primary mirror.  Which of the following is true:

A) It gathers twice as much light as a telescope with a 4 inch diameter mirror

B) It gathers four times as much light as a telescope with a 4 inch diameter mirror

C) It gathers half as much light as a telescope with a 16 inch diameter mirror

D) It gathers 2.54 times as much light as a telescope with an 8 cm diameter mirror

E) It gathers more light than an eight inch refractor.

6) A telescope has an 8 inch diameter primary mirror.  Which of the following is true:

A) It resolves details twice as small as a telescope with a 4 inch diameter mirror

B) It resolves details four times as small as a telescope with a 4 inch diameter mirror

C) It resolves details almost as small as a telescope with a 16 inch diameter mirror

D) It can resolve details as small as 0.01 arc seconds

E) It can see the Apollo 11 flag on the Moon.

C B D C B   A

• Kepler's Laws (7 questions)

1) Which statement about planetary orbits is incorrect?

A) All planets orbit the Sun counterclockwise.

B) Most stay close to the earth's equator in the sky.

C) Most orbits are almost circular, with low eccentricities.

D) All have the Sun at one focus of their elliptical orbits.

E) Most also rotate counterclockwise on their axes as well.

2) Two planets have orbits with the same sized semi-major axis. Which is true?

A) The planet with the most eccentric orbit moves faster all the time.

B) The planet with the most eccentric orbit moves faster some of the time.

C) The planet with the most eccentric orbit never moves faster.

D) Not enough information to answer.

3) A planet orbit could be circular.

A) True

B) False

4) Assume a planet orbits exactly three times as far from the Sun as the Earth.

A) It’s period is 3 years exactly.

B) It’s period is between 3 and 5 years

C) It’s period is between 5 and 7 years

D) It’s period is 7 years or more.

5) Assume a planet orbits exactly twice as far from the Sun as the Earth does.

A) It’s period is 2 years exactly.

B) It’s period is between 2 and 3 years

C) It’s period is between 3 and 4 years

D) It’s period is 4 years exactly.

6) Planetary orbits are

A) Circular.

B) Parabolic.

C) Elliptical.

D) Hyperbolic.

7) Two planets have orbits with the same periods. Which is true?

A) Their velocities must be the same.

B) They must have the same eccentricity.

C) They must have the same semi-major axis.

D) Their orbits must be identical.

B B A C B    C C

• Newton’s Laws and Gravity  (6 questions)

1) A brick hits a glass window. The brick breaks the glass, so the magnitude of the force of the brick on the glass is

A) is greater than the magnitude of the force of the glass on the brick

B) is smaller than the magnitude of the force of the glass on the brick

C) is equal to the magnitude of the force of the glass on the brick

D) none of the preceding

2) An iron weight and a styrofoam ball are dropped from the same height at the same time.

Which hits the ground first?

A) The iron weight

B) The styrofoam ball

C) They hit at the same time

3) Which has the most kinetic energy?

A) A 1 kg Mass with velocity 4 m/s.

B) A 2 kg Mass with velocity 3 m/s.

C) A 3 kg Mass with velocity 2 m/s.

D) A 4 kg Mass with velocity 1 m/s.

4) A net force of 15 N is applied to an object with mass 5 kg. According to Newton’s 2nd Law…

A) The acceleration is 3 m/s2

B) The acceleration is 45 m/s2

C) The acceleration is 15 m/s2

D) The acceleration is .25 m/s2

5) Which mass pair has the greatest gravitational force between them?

A) A 5Msolar mass and a 4Msolar mass separated by 4 AU.

B) A 4Msolar mass and a 3Msolar mass separated by 3 AU.

C) A 3Msolar mass and a 2Msolar mass separated by 2 AU.

D) A 2Msolar mass and a 1Msolar mass separated by 1 AU.

6) On top of a very high mountain, you would "weigh"…

A) Less than at sea level

B) The same as at sea level

C) More than at sea level.

C C B A D   A