Astronomy Midterm Astronomy Midterm ReviewReview

Some Questions 1Some Questions 1

Most minor planets have orbits which Most minor planets have orbits which lie completely in the orbits of the lie completely in the orbits of the planets Mars and”planets Mars and”

JupiterJupiter

22

Rocky debris larger than 100 meters Rocky debris larger than 100 meters in diameter seen orbiting the sun in diameter seen orbiting the sun are:are:

asteroidsasteroids

33

The _______ Cloud is a huge, spherical The _______ Cloud is a huge, spherical region at the outer edge of the solar region at the outer edge of the solar system, populated by many dark, system, populated by many dark, cold cometary nuclei; Sedna is the cold cometary nuclei; Sedna is the largest member of it found to date.largest member of it found to date.

OortOort

44

The _______Belt is a second, larger The _______Belt is a second, larger asteroid belt out beyond the orbit of asteroid belt out beyond the orbit of Neptune.Neptune.

KuiperKuiper

55

Although numbering perhaps a few Although numbering perhaps a few billion distributed over a spherical billion distributed over a spherical volume of 100 000 A.U. in diameter, volume of 100 000 A.U. in diameter, _______ are a minor constituent to the _______ are a minor constituent to the total mass of the solar system.total mass of the solar system.

cometscomets

66

The bluish _______tail of a comet is The bluish _______tail of a comet is pushed radially outward by the pushed radially outward by the effects of the solar wind.effects of the solar wind.

gas or iongas or ion

77

The curved, yellowish ______ tail of a The curved, yellowish ______ tail of a comet is left behind in the cometary comet is left behind in the cometary orbit.orbit.

dustdust

88

The _______ is the fuzzy spherical The _______ is the fuzzy spherical outgassing around the nucleus of a outgassing around the nucleus of a sun-bound comet.sun-bound comet.

comacoma

99

The nucleus of a comet is composed The nucleus of a comet is composed primarily of:primarily of:

ices.ices.

1010

We now recognize that the largest We now recognize that the largest Kuiper Belt Object is:Kuiper Belt Object is:

PlutoPluto

1111

While long period comets are from While long period comets are from the Oort Cloud, some short period the Oort Cloud, some short period comets may come from the closer comets may come from the closer _______ Belt._______ Belt.

KuiperKuiper

1212

The most common class of meteorite The most common class of meteorite is:is:

stony.stony.

1313

The meteorites that are rich in The meteorites that are rich in organic molecules are classified as:organic molecules are classified as:

Carbonaceous Carbonaceous (chondrite).(chondrite).

1414

A solid object from outer space that A solid object from outer space that lands on the surface of any world is lands on the surface of any world is known as a:known as a:

meteorite meteorite

1515

Small debris in the solar system less Small debris in the solar system less than 100 meters in diameter are than 100 meters in diameter are called _______; most are not detected called _______; most are not detected unless they hit our atmosphere.unless they hit our atmosphere.

meteoroidsmeteoroids

1616

Few _______ actually strike the Earth, Few _______ actually strike the Earth, because most are small and burn up because most are small and burn up in the atmosphere.in the atmosphere.

meteorsmeteors

1717

The K-T Boundary Event happened The K-T Boundary Event happened about 65 million years ago when an about 65 million years ago when an asteroid the size of a small city asteroid the size of a small city struck the _______ Peninsula.struck the _______ Peninsula.

YucatanYucatan

1818

Most meteor showers occur _____, as Most meteor showers occur _____, as we again intersect the comet’s orbit.we again intersect the comet’s orbit.

annuallyannually

1919

All eight major planets travel in orbits All eight major planets travel in orbits which lie near to the:which lie near to the:

ecliptic.ecliptic.

2020

In the currently accepted theory for In the currently accepted theory for the formation of the solar system, the formation of the solar system, the planets and other minor bodies the planets and other minor bodies and the ________ formed at the same and the ________ formed at the same time.time.

SunSun

2121

Most of the angular momentum of Most of the angular momentum of the solar system is found in the: the solar system is found in the:

orbits of the planets.orbits of the planets.

2222

Most of the mass of the solar system Most of the mass of the solar system is found in the:is found in the:

Sun.Sun.

2323

The ecliptic plane is also the Sun's:The ecliptic plane is also the Sun's:

equator.equator.

2424

Of all the planets, ________ is far and Of all the planets, ________ is far and away the most massive, and controls away the most massive, and controls much of how the rest of the planets much of how the rest of the planets condensed out of the solar nebula.condensed out of the solar nebula.

JupiterJupiter

2525

While all planet orbits are ellipses, While all planet orbits are ellipses, the eight large planets have fairly the eight large planets have fairly ________ eccentricities.________ eccentricities.

lowlow

2626

A ________ planet is a relatively small A ________ planet is a relatively small body formed in the inner part of the body formed in the inner part of the solar system from condensation of solar system from condensation of metallic elements and rocky metallic elements and rocky compounds.compounds.

terrestrialterrestrial

2727

Bodies just large enough for their Bodies just large enough for their gravitational forces to attract other gravitational forces to attract other nearby bodies are called:nearby bodies are called:

planetesimals planetesimals

2828

Early in the history of the solar Early in the history of the solar nebula, small condensation nuclei nebula, small condensation nuclei grew rapidly in size by the process grew rapidly in size by the process of:of:

accretionaccretion

2929

The ________ theory describes the The ________ theory describes the origin of the planets as having been origin of the planets as having been formed by accretion of small formed by accretion of small particles into progressively larger particles into progressively larger and larger bodies.and larger bodies.

condensationcondensation

3030

The chemical composition The chemical composition differences between the planets are differences between the planets are basically the result of the fact that basically the result of the fact that different elements condense out of different elements condense out of gas at different:gas at different:

temperatures.temperatures.

3131

While the Sun gathered up most of While the Sun gathered up most of the ________, the planets ended up the ________, the planets ended up with most of the angular momentum, with most of the angular momentum, as evidenced by their revolution as evidenced by their revolution around the Sun.around the Sun.

massmass

3232

The age of the solar system, of 4.6 The age of the solar system, of 4.6 billion years, is determined from billion years, is determined from dating of:dating of:

meteorites.meteorites.

3333

A good example of the role of A good example of the role of catastrophes is the very large catastrophes is the very large ________ circling us.________ circling us.

MoonMoon

3434

The very odd tilt of the planet The very odd tilt of the planet ________ is another example of the ________ is another example of the role major impacts may have played role major impacts may have played in creating irregularities in the in creating irregularities in the present solar system.present solar system.

UranusUranus

3535

All of the planets found orbiting other All of the planets found orbiting other stars have been most similar to stars have been most similar to ________, except most of them have ________, except most of them have been much closer to their star than been much closer to their star than this planet is to the Sun.this planet is to the Sun.

JupiterJupiter

3636

The planets orbiting other stars so The planets orbiting other stars so far have been found by ________ far have been found by ________ shifts of the star's spectra.shifts of the star's spectra.

DopplerDoppler

3737

The Sun has about the same average The Sun has about the same average density as the planet:density as the planet:

Jupiter.Jupiter.

3838

Helios was the Greek name for the:Helios was the Greek name for the:

Sun.Sun.

3939

Energy produced in the solar core Energy produced in the solar core takes ________ to appear at the solar takes ________ to appear at the solar surface.surface.

a million yearsa million years

4040

Solar energy production is mainly Solar energy production is mainly due to the ________ cycle of due to the ________ cycle of thermonuclear reactions as hydrogen thermonuclear reactions as hydrogen nuclei collide violently.nuclei collide violently.

proton-protonproton-proton

4141

The radioactive decay of U 238 in the The radioactive decay of U 238 in the Earth's core is a good example of the Earth's core is a good example of the nuclear:nuclear:

fission.fission.

4242

In time, the fusion reactions will In time, the fusion reactions will cause the amount of helium to cause the amount of helium to ________ in the sun's core.________ in the sun's core.

increaseincrease

4343

The weakest of the forces in nature The weakest of the forces in nature is:is:

gravity.gravity.

4444

The solar photosphere is not uniform The solar photosphere is not uniform in brightness, but has a mottled in brightness, but has a mottled appearance termed:appearance termed:

granulation.granulation.

4545

Energy transport as hot gases rise Energy transport as hot gases rise can occur by large-scale motions of can occur by large-scale motions of the solar material in regions called: the solar material in regions called:

convective zones.convective zones.

4646

The observable ________ is a thin The observable ________ is a thin layer in which the solar material layer in which the solar material becomes suddenly much more becomes suddenly much more opaque as we look deeper into the opaque as we look deeper into the Sun.Sun.

photospherephotosphere

4747

In contrast to the photosphere's In contrast to the photosphere's continuum, the spectrum of the continuum, the spectrum of the chromosphere is dominated by chromosphere is dominated by ________ lines.________ lines.

emissionemission

4848

The ________ is the outermost, The ________ is the outermost, hottest part of the Sun's atmosphere.hottest part of the Sun's atmosphere.

coronacorona

4949

The most visible interaction of the The most visible interaction of the solar wind with our magnetic field is solar wind with our magnetic field is the:the:

auroraaurora

5050

The ________-year solar cycle is The ________-year solar cycle is characterized by a variation in the characterized by a variation in the number of sunspots and a reversal of number of sunspots and a reversal of the polarity of the Sun as a whole.the polarity of the Sun as a whole.

2222

5151

The solar magnetic field is strongest The solar magnetic field is strongest in those regions called ________, in those regions called ________, which are poles and usually thus which are poles and usually thus occur in pairs.occur in pairs.

sunspotssunspots

5252

The only particle we can detect The only particle we can detect coming directly from a stellar interior coming directly from a stellar interior is the:is the:

neutrino.neutrino.

5353

The method by which we obtain The method by which we obtain distances to the nearest stars is distances to the nearest stars is through the use of: through the use of:

parallax shifts.parallax shifts.

5454

A star with a parallax of 1 second of A star with a parallax of 1 second of arc is at a distance of ________ by arc is at a distance of ________ by definition.definition.

one parsecone parsec

5555

The ________ magnitude of a star The ________ magnitude of a star depends directly upon its luminosity depends directly upon its luminosity and distance.and distance.

apparentapparent

5656

The Sun's absolute magnitude is: The Sun's absolute magnitude is:

+4.82 or +4.8 or +5+4.82 or +4.8 or +5

5757

From hottest to coolest, the seven From hottest to coolest, the seven letters for the star types are:letters for the star types are:

OBAFGKMOBAFGKM

5858

Most of the apparently bright stars in Most of the apparently bright stars in the sky are bright because they are:the sky are bright because they are:

very hot or very very hot or very luminousluminous

5959

Knowing the apparent temperature Knowing the apparent temperature of a star, its luminosity may be of a star, its luminosity may be calculated if we also know its calculated if we also know its ________.________.

sizesize

6060

Absorption lines in stellar spectra are Absorption lines in stellar spectra are caused by the absorption of photons caused by the absorption of photons of specific energy when electrons of specific energy when electrons jump from one energy level to a jump from one energy level to a ________ level.________ level.

higherhigher

6161

Compact stars that are typically as Compact stars that are typically as big as the largest sunspots on our big as the largest sunspots on our star are:star are:

white dwarfs.white dwarfs.

6262

Stars of the ________, like our Sun, Stars of the ________, like our Sun, are converting hydrogen into helium, are converting hydrogen into helium, and are common.and are common.

main sequencemain sequence

6363

On the main sequence, our Sun lies On the main sequence, our Sun lies about:about:

the center.the center.

6464

The binary systems that allow us to The binary systems that allow us to directly calculate the diameters of directly calculate the diameters of each star are:each star are:

eclipsing. eclipsing.

6565

A star's position on the Main A star's position on the Main Sequence is determined Sequence is determined fundamentally by its:fundamentally by its:

mass.mass.

Questions from Questions from ““Instructor Resource Center.”Astronomy Instructor Resource Center.”Astronomy

Today. CD-ROM. Fifth Edition. Upper Today. CD-ROM. Fifth Edition. Upper Saddle River, New Jersey, 2005.Saddle River, New Jersey, 2005.