Review Exercise Solution

Fill in the Blanks

 

n  The __________________ is the totality of all space, time, matter, and energy.  universe

 

n  A grouping of stars by humans into recognizable patterns is called a _______________ 

     constellation

 

n  An imaginary sphere surrounding Earth to which all objects were once considered attached

     is called the ________________________ celestial sphere

 

n  _____________ is measured in degrees north or south of the celestial equator, just as

     latitude is measured north or south of the Earth's equator.  Declination

 

n  _____________ is measured in units called hours, minutes, and seconds, and it increases in

    the eastward direction. Right ascension

 

n  The ____________________ model of the universe was based on the assumption that the

     Sun, moon, and planets all orbit around the Earth.  Geocentric

 

n  The ____________________ model of the universe was based on the assumption that Earth

     and the other planets orbit the Sun.  Heliocentric

 

n  The distance from the Earth to the Sun is called the _____________________ astronomical

     unit

 

n  The motion induced change in the observed frequency of a wave is called the

      ______________ effect. Doppler

 

n  Stars in space that are moving toward us appear ________________ shifted (a color)  blue

 

n  Stars in space that are moving away from us appear ________________ shifted (a color)

     red

 

n  A ______________________ is a device for splitting a bean of radiation into its component

    frequencies and delivering them to a screen or detector for detailed study. These devices

    allow us to obtain information about stars. spectroscope

 

 

n  This German physicist summarized the observed relationships among the three types of

     spectra. He formulated three rules that  now are named after him. His name is

     ____________________________Gustav Kirchoff

 

n  The three types of spectra are

 

      Þ _____________________________   continuous

 

      Þ _____________________________   emission line

 

      Þ _____________________________   absorption line

 

n  Optical telescopes are designed specifically to collect the wavelengths that are visible to the

     human eye. Optical telescopes fall into the following 2 basic categories

 

      Þ _____________________________     reflectors

 

      Þ _____________________________     refractors

 

n  Because the atmosphere is no hindrance to long-wavelength radiation, astronomers have

     built a number of ground-based ______________________________ capable of detecting

     these signals from space.  One of the largest of this type telescope is in West Virginia.  

     Radio telescopes

 

n  The main disadvantage of the above type telescope is its relatively poor angular resolution.

     In some circumstances, however, this limitation can be overcome with a technique known as

     ______________________________ interferometry. This approach uses two or more such

     telescopes in tandem to observe the same object at the same wavelength and at the same

     time.  interferometry

 

n  The individual that first proposed an expanding universe is __________________________   

     LeMaitre.

 

 

n  Some characteristics of planets are listed in the left column below. Indicate whether the

    characteristic, in general, applies to either a terrestrial or jovian planet by placing a check

    mark (Ö) in the appropriate column.

 

 

Characteristic	Jovian	Terrestrial
Closest to the Sun		Ö
Closely spaced orbits		Ö
Small masses		Ö
Large radii	Ö
No solid surface	Ö
Low density	Ö
Slower rotation		Ö
Few moons		Ö
No rings		Ö

 

n  Mission scientists often use their knowledge of the above discipline to carry out

     _________________ maneuvers which can boost an interplanetary probe into a more

     energetic orbit and also aid navigation toward the target at no additional cost.  slingshot

 

n  A large cloud of interstellar dust is called a ______________________ nebula

 

n  The French mathematician-astronomer Laplace showed mathematically that conservation of

     _________________________________ demands that nebula spin faster as they contract.

     This decrease in size of a rotating mass must be balanced by an increase in its rotational

     speed.  angular momentum

 

n  The _____________________________ theory rests on the old nebular theory investigated

     by Laplace but combining it with new information about interstellar chemistry to avoid most of

     the original theory's problems.  condensatation

 

n  ______________________________ refers to comparing and contrasting the properties of

     the diverse worlds we encounter to better understand the conditions under which the planets

     form and evolve.  Comparative Planetology

 

n  The ________________________ belt is located roughly between Mars and Jupiter 

     Asteroid

 

n  The ____________________________ belt lies outside Neptune's orbit.  Kuiper

n  The planet closest to the Sun is _______________________ Mercury

 

n  Most celestial objects rotate.   _______________________________ is a tendency of an

    object to keep rotating; it is proportional to the mass, radius, and rotation speed of the body.  

    Angular momentum

 

n  One of the earliest models of solar system formation dates back to Descartes. It involves a

     large cloud of gas that began to collapse under its own gravity to form the sun and planets.

    This is referred to as _______________________ theory.  Nebular

 

n  A currently favored model of solar system formulation combines features of the old theory of

    Descartes with new information about interstellar dust grains which acted as condensation

    nuclei. This theory is called ______________________ theory.  Condensatation

 

n  A ______________________________ assist can be used to conserve fuel when travelling

     between planets. A spacecraft using this technique uses the gravity of a planet or moon to

     pull itself around the mass at greater speed.  gravitational assist or slingshot

 

n  The ________________________ orbit was first devised by the German scientist Walter

     Hohmann.  It was used in the Cassini Mission.  Hohmann Transfer

 

n  A ______________________________ is a chunk of interplanetary debris prior to

     encountering Earth’s atmosphere. meteoroid

 

n  A bright streak in the sky, often referred to as a “shooting star”, resulting from a small

     piece of interplanetary debris entering Earth’s atmosphere and heating air molecules,

     which emit light as they return to their ground states. ________________ meteor

 

n  A _______________________ is a small body, composed mainly of ice and dust, in an

     elliptical orbit about the sun. As it comes close to the Sun, of its material is vaporized to

     form a gaseous head and extended tail.  comet

 

n  Any part of a meteoroid that survives passage through the atmosphere and lands on the

     surface of the Earth is called a ____________________meteorite

 

Mars

 

Indicate whether the following statements about the listed items are true or false by placing a check mark (√) in the appropriate column

 

Statement	True	False
Fourth planet from the Sun	√
A year is about twice as long as on Earth	√
Length of a day is about the same as on Earth	√
Rotates from East to West	√
Orbits Sun in an elliptical shape	√
Surface seems to lighten and darken because of dust storms	√
No magnetic field surrounding the planet	√
It is the planet most like Earth	√

 

Circle the correct answer

 

n  Mars' Valles Marineris is

    a) a valley as wide as the U.S. possibly caused by a meteor striking the surface

    b) a canyon as wide as the Grand Canyon is long and possibly caused by erosion

    c) the same size as the Grand Canyon and possibly caused by volcanic activity

    d) a canyon as wide as the U.S. possibly caused by volcanic activity

 

answer: d

 

n  The Mariner 9 mission was engineered to

    a) orbit Mars and take pictures to be used to map out the planet

    b) search for life

    c) investigate the face on Mars

    d) none of the above

    e) all of the above

 

answer: a

 

 

Moon

 

Indicate whether the following statements about the listed items are true or false by placing a check mark (√) in the appropriate column

 

Statement	True	False
Gravitational force is less than that on earth	√
The fission theory involves the Moon splitting from Mars		√
Five theories for the Moon's formation were discussed	√
The current belief is that the Moon was formed about 6 billion years ago		√

 

n  Only 2 planets do not have any moons. They are __________________ and ________________________  Mercury    Venus
 

n  List the 4 theories for the formation of Earth's moon

 

1. The Fission Theory:

The Moon was once part of the Earth and somehow separated from the Earth early in the history of the Solar System. The present Pacific Ocean basin is the most popular site for the part of the Earth from which the Moon came

 

2. The Capture Theory:

The Moon was formed somewhere else, and was later captured by the gravitational field of the Earth.

 

3. The Condensation Theory:

The Moon and the Earth condensed together from the original nebula that formed the Solar System.

 

4. The Colliding Planetesimals Theory:

The interaction of earth-orbiting and Sun-orbiting planetesimals (very large chunks of rocks like asteroids) early in the history of the Solar System led to their breakup. The Moon condensed from this debris.

 

 

Sun

 

Indicate whether the following statements about the listed items are true or false by placing a check mark (√) in the appropriate column

 

 

Statement	True	False
Creates energy by the process of nuclear fission		√
Earth has the most ideal position for life in relation to the sun	√

 

Answer the following questions

 

n  When can you see the corona of the sun?  During a total solar eclipse

 

n  What type of star is our sun?  Yellow Dwarf

 

n  What is the goldilocks effect?  Being the perfect distance away from the sun to have liquid water and thus life

 

n  Who first observed and recorded sunspots?  Galileo Galilee

 

n  What does NOAA stand for?  National Oceanic and Atmospheric Administration

 

n  What triggers most sever solar storms, on Earth from the sun?  Sun spots

 

n  What brings rays of sun to earth?  Photons

 

Jupiter

 

Indicate whether the following statements about the listed items are true or false by placing a check mark (√) in the appropriate column

 

Statement	True	False
It is a terrestrial planet		√
Has a radius about 11 times that of earth	√
Less dense than Earth	√
It has no seasons	√
Great Red Spot is caused by lava flows		√
Magnetosphere is largest entity in the solar system	√
Has more moons than any other planet	√
The moon Europa is the one most likely to have life	√

 

Circle the correct answer

 

n  Jupiter's moon, Ganymede, is

    a) heavily cratered

    b) icy, with the possibility of microbial life

    c) the largest moon in the solar system

    d) covered in active volcanoes

 

answer: c

 

 

Earth

 

Four threats to Earth were discussed. List each below

 

1. Near Earth Encounter

 

2. Exploding Star

 

3. Death of our Sun

 

4. The Big Rip

 

n  G is the gravitational constant and its value is 6.67x10^-11 Nm²   

 

Assume that the mass of a planet is  1.0x10²⁴ kg and its radius is  1.0 x10²⁶ km

What would be the acceleration due to gravity on this planet?

F = M₁a₁ = GM₁M₂/r²

 

Note that in the above equation, the mass of M₁ cancels so you are left with the following

a = GM/r²  = (6.67x10^-11)(1.0x10²⁴)/(1.0x10²⁶)²

 

a = 6.67 x 10¹⁵