ASTRONOMY 101

Mesa College

Spring 2004

Third Examination

NAME______________________________(Print) Lec. hr.______ days class meets______

NAME______________________________(Signature) select best answer

1 The particle in space called a _________ passes through Earth's atmosphere, heats

up, and glows. It is then called a _________. Finally, when the particle reaches

the surface of Earth, it is called a __________.

a. meteoroid; meteor; meteorite

b. meteor; meteorite; meteoroid

c. meteorite; meteoroid; meteor

d. meteorite; meteor; meteoroid

2 Studying crystals in iron-nickel meteorites enables us to determine that these meteorites were

a. once fairly hot and cooled very slowly

b. formed near the surface of an asteroid

c. formed beyond the orbit of Jupiter

d. often in retrograde (clockwise) orbits

e. once very cold and warmed up very slowly

3 Some meteor showers are best explained as being the remnants of

a. artificial satellites d. a collision of two planets

b. minor planets e. none of the other answers

c. remnants of old comets

4 The tail of a comet is directed

a. toward the sun when approaching and away from the sun when

receding

b. away from the sun at all times

c. toward the sun at all times

d. away from the sun when approaching and toward the sun when

receding

5 The tail of the comet is produced by the

a. magnetosphere of Earth c. magnetosphere of Jupiter

b. solar wind d. gravitational field of the sun

6 Most comets possess a tail throughout their entire orbit.

a. true b. false

7 A comet has been observed to strike a planet in our Solar System..

a. true b. false

8 The large reservoir of comet nuclei far beyond Pluto, from which we believe new comets come into the inner solar system is called:

a. the Lowell reservoir d. the Oort Cloud

b. the Kohoutek Cloud e. the Alvarez belt

c. Bayonne, New Jersey

9 A main difference between asteroids and comets is that asteroids are mostly made of rock and comets are mostly made of

a. metals d. carbon compounds

b. water vapor

c. ice e. you can't fool me, astronomers don't really know what comets are made of

10 The largest minor planet is

a. as big as the Earth

b. smaller than the Earth but bigger than the moon

c. five or ten km in diameter

d. smaller than the diameter of the moon, but more that 100 miles

11 The age of the oldest meteorites is thought to be approximately _____________ years.

a. 100 million c. 2 trillion

b. 1 billion d. 4 - 5 billion

12 Predictable meteor showers are often associated with the orbits of periodic comets(existing now or have existed in the past).

a. true b. false

13 The orbits of most minor planets(asteroids) lie

a. between the orbits of Mars and Earth

b. between the orbits of Mercury and Venus

c. beyond the twilight zone

d. between the orbits of Jupiter and Saturn

e. between the orbits of Jupiter and Mars

14 The sunspot cycle is a period of about 11 years during which

a. the sun and spots on it make one complete rotation

b. the average number of spots starts at a minimum and then arises to a

maximum and then back to a minimum

c. the material comprising a spot makes a complete revolution

d. the spots move from one pole of the sun to the other

15 The second most abundant element in the sun is

a. hydrogen d. helium

b. carbon e. oxygen

c. nitrogen

16 The sun is stable and does not collapse because

a. the sun has a solid metallic core supporting the outer layers

b. it is held together by strong magnetic fields

c. it is very hot inside causing sufficient internal pressure to prevent

a collapse

d. it is not massive enough to collapse under any circumstances

e. Who can say? It may collapse tomorrow.

17 Granulation in the sun results from

a. magnetic fields in the corona

b. magnetic fields in the chromosphere

c. rising hot volumes of gas in the photosphere

d. sunspots

e. irregular, uneven radio waves generated in the sun

18 Sunspots appear dark because they are

a. dark objects seen passing in front of the sun

b. much cooler than the surrounding corona

c. much cooler than the surrounding photosphere

d. over-sized faculae

19 The bright apparent surface of the sun, from which most of our sunlight is received, is called the

a. chromosphere d. convection zone

b. photosphere e. heliosphere

c. corona

20 Convection is the process of transporting energy by

a. photons traveling at the speed of light

b. the movement of matter from one location to another

c. the vibrations of adjacent atoms

21 Sunspots are located in the

a. corona c. core

b. chromosphere d. photosphere

22 The maunder minimum is

a. followed after 11 years by a maunder maximum

b. a period when the least number of maunders can be observed on the

solar disk

c. the period during magnetic field reversal when the solar magnetic field is at a minimum

d. an extended period of low solar activity

e. the region of coolest temperature in the vicinity of a sunspot

23 Coronal holes are thought to be the source of

a. the solar wind c. sunspots

b. flares d. magnetic storms

24 According to the mass-luminosity relationship, the more massive a star is, the more light it gives off.

a. true b. false

25 The least massive stars known have masses about

a. thousand times smaller than the sun

b. 1/2 the mass of the sun

c. a few hundredths that of the sun

d. million times small than the sun

26 The stars which lie closest to the sun in space are mostly

a. hotter than the sun d. younger than the sun

b. much less luminous than the sun e. larger in mass than the sun

c. much more luminous than the sun

27 The letters classifying the spectral sequence of stars from blue to red (high temperature to low temperature) are

a. B A F K G M O d. O B A F G K M

b. O B A F K M G e. M G K F A O B

c. M K G F A B O

28 A color index is a direct measurement of a star's

a. radial velocity c. temperature

b. size d. composition

29 Which of the following binary systems can best be used to determine the radii of the stars?

a. visual binary c. spectroscopic binary

b. eclipsing binary d. astrometric binary

30 A binary star system that is identified because of a change in brightness due to one star of the system passing in front of the other is classed as a(n)

a. visual binary c. spectroscopic binary

b. eclipsing binary d. astrometric binary

31 Where on the H-R diagram are the extremely bright, large diameter, but cool surface temperature stars found?

a. red giant and supergiant branch (upper right)

b. lower left corner (white dwarf region)

c. lower main sequence

d. upper main sequence

32 If star A has a larger proper motion than star B, star A is probably

a. more distant from us than star B

b. nearer to us than star B

33 A splitting of spectral lines caused by a magnetic field around a light source is

called

a. dispersion d. the Zeeman effect

b. diffraction e. magnetic flaring

c. nuclear fission

34 Large loops or protrusions of hot material extending hundreds of thousands of kilometers above the edge of the visible disk of the sun are called

a. flares d. prominences

b. spicules e. superspots

c. plages

35 The solar wind is(are)

a. charged particles emitted from the sun

b. storms in the sun's interior

c. coronal material falling into the sun

36 The principal source of energy for the sun and most other stars is

a. chemical oxidation d. hydrogen fusion

b. uranium fission e. helium fusion

c. hydrogen fission

37 Which of the following is the more violent phenomena found on the Sun?

a. sunspots b. granules c. flares d. prominences

38 The hottest layer of the sun's atmosphere is

a. photosphere b. chromosphere c. corona

39 The Sun rotates once on its axis approximately once every

a. day b. month c. year

40 We are interested in detecting solar neutrinos because:

a. They tell us what was happening in the Sun's interior less than 10 minutes ago. b. These particles have only been theoretically suggested to exist.

c. Well, you really can't detect them because they have no mass and no charge.

d. They are related to how active the Sun's surface is.

41 A binary star that can be resolved into individual stars when viewed through a telescope is classed as a(n)

a. visual binary c. spectroscopic binary

b. eclipsing binary d. astrometric binary

42 In which portion of the Hertzsprung-Russell diagram, as it is usually presented, do we find stars of the highest average density?

a. upper left corner c. upper right corner

b. center of main sequence d. lower left corner

43 Energy transfer from the Sun to the Earth is through

a. conduction b. radiation c. convection

44 The binding energy of an atom is:

a. the amount of energy the atom acquires as it gets hotter

b. the amount of energy an atom has relative to the hydrogen atom

c. the energy required to completely separate the particles in the nucleus of an atom

d. none of the above

45 Most comets

a. have periods greater than 100 years

b. have periods less than 100 years

c. bring bad tidings

46 The Trojan asteroids are found to be in orbits

a. between Mars & Jupiter c. with Jupiter

b. beyond Pluto d. about the Earth

47 The absolute magnitude of a star is defined as

a. how bright a star appears to us in the sky.

b. how bright a star would appear if it were at a distance of 10 parsecs.

c. the radiative flux in Watts per square meter received.

d. the wavelength at which the star is brightest.

e. the distance at which it would appear as bright as the star Vega.

Describe the following modes of energy transport discussed in class. 2 points each

1 (convection)

2 (conduction)

Give two(2) important differences, discussed in class, between the giant planets and the terrestrial planets. 2 points

1

2

What forces us to believe that carbonaceous meteorites have spent most of their lifetimes far from the Sun and therefore in a cold environment? These meteorites are rich in the lighter elements and contain water. 2 points

Is your name on the scantron and the examination? ______ 1 point