Honors Astronomy Final REVIEW
The average rate of erosion on the Moon is far less than that on the Earth because:
The Moon lacks wind and running water
Astronomers believe that the Moon never entirely melted because
Being less massive than Earth, the Moon does not contain enough radioactive elements to heat it to the melting point.
Ocean formation allowed the Earth to remove much of the ______ from our atmosphere
carbon dioxide
Which atmospheric component is chiefly a product of life processes?
Oxygen
Seismic waves are most useful for mapping
the Earth’s mantle and core
Which statement about our core is false?
It generates a strong, stable magnetic field
Which statement about seismic waves is false?
Directly opposite the epicenter, only S waves arrive
Which of the following regions of the Earth appears to be unique among the terrestrial planets?
Hydrosphere
Which two gases are the primary present constituents of our atmosphere?
nitrogen and oxygen
Which of these gases was not outgassed in forming our secondary atmosphere?
Oxygen
Almost all of the Earth’s atmospheric gases lie in the:
troposphere
Which of these is not a product of plate tectonics?
The Grand Canyon
Which of the following creates the greatest tidal impact on Earth?
The Moon
The region in which charged particles are trapped by our magnetic fields are the:
Van Allen Belts
The principal greenhouse gases in our present atmosphere are:
carbon dioxide and water vapor
Compared to the density of water, at one gram/cc, the Earth’s density on average is about:
5.5 times denser
When strong solar wind storms are directly poleward by our magnetic field lines, we get:
auroral displays
Which body has the greater gravitational pull on the entire Earth?
Sun
The lunar mare are found
Predominately on Earth side
The moon’s atmosphere is composed of:
It has no atmosphere
What do moonquakes reveal about the lunar interior?
They show that the Moon might have a small, partially molten core.
Would the moon be a good place to do astronomy?
Yes, because the Moon lacks an atmosphere
What theory of the Moon’s origin is favored by most astronomers?
The Moon originated as material torn from Earth by the collision of a large mars-sized body
What is the age of the lunar maria compared to the 4 billion year age of the highlands?
3.2 to 3.9 billion years
What force on the Moon causes it to keep a single hemisphere toward Earth?
Tidal Force
The rate of cratering on the lunar highlands helps to show that:
They are older than the maria
One of the following factors, along with temperature, determines whether a body will retain an atmosphere of a given composition.
escape velocity
Based on the presence of lunar mare chiefly on the side facing us, we conclude:
the crust on our side must be thinner than that under far side
Which of the following is not a factor in determining whether a body in the solar system retains an atmosphere?
rate of rotation
Two forms of electromagnetic radiation that penetrate Earth’s atmosphere are:
Visible light and radio waves.
What is spectroscopy?
an analysis of the way in which atoms absorb and emit light
In the atom, what type of particle determines the element that atom represents?
protons
Spectral lines are sometimes referred to as the stars “fingerprints” because:
Both are unique and characteristic of that which has produced them. Fingerprints also consist of individual lines that combine to make a pattern,Both can be categorized, ALL OF THESE
Line boadening is caused by:
Atoms in thermal motion, Magnetism, Rotation -ALL OF THESE
The part of the atom responsible for its chemical reactions is the
Electron
A hydrogen atom consists of:
One electron orbiting a proton
What is emitted from an atom when one of its electrons makes a transition from a higher energy state to a lower energy state:
Photon
The particle which adds mass but no charge to the atomic nucleus is the:
Neutron
What discovery resulted from the photoelectric effect
The particle nature of light
If you view a hot star through a cool cloud of gas, what sort of spectrum are you likely to see?
Absorption
What is the classic continuous spectrum?
A rainbow
An incandescent light bulb (glowing hot tungsten filament) produces which spectrum?
Continuous
A neon light (thin hot neon gas in a vacuum tube) produces which type of spectrum?
Emission
The Orion Nebula is a hot, thin cloud of glowing gas, Which describes its spectrum?
A few bright lines on a dark background
Typical stellar spectra appear as:
A rainbow with dark lines mixed in
Why are most large telescopes reflectors, not refractors?
Large lenses deform under their own weight, while large mirrors can be supported
Which of the following is not an advantage of the Hubble Space Telescore over ground-based telescopes?
It is larger than any Earth based instrument
What is the primary advantage of the Hubble Space Telescope over ground-based telescopes?
It is above the atomosphere
What problem is adaptive optics used to correct?
Effects of atomospheric turbulence
Diffraction is the tendency of light to
Spread around corners
It is diffraction that limits the _of a telescope, given its objective’s aperture
Resolution
Which statement best express the advantages of large telescopes over small ones?
Large telescopes collect more light than small ones and they bring the light to a sharper focus
What is the resolving power of a telescope?
Its ability to distinguish two adjacent objects in the sky
Contrast the resolving power of a Celestron C-8 with its finder, given the main scope has an aperture eight times larger than its finder lens
8X better detail
Contrast the light grasp of a Celestron C-8 with its finder, given the main scope has an aperature 8X larger than its finder
64X fainter stars
What is the primary advantage of CCDs over photographic plate?
They record up to 75 percent of the light instead of only 5 percent
What is the primary purpose of an astronomical telescope?
to collect a large amount of light and bring it to a focus
In which part of the spectrum is there no information coming to us from space and is therefore not observed by astronomers?
Gamma Rays, Ultra Violet, Infrared– NONE OF THESE
Which of the following is a problem inherent to all large radio telescopes?
They have poor angular resolution
A mountain top is a good location for optical and infrared telescopes because the site
is above much of the atomosphere
The amount of diffraction depends on what factor or factors
The wavelength used and the telescope size
For what is an interferometer used?
To improve the angular resolution of radio telescopes
This type of telescope has its focus is behind the back of the hole in the main mirror
Cassegrain
Refracting telescopes suffer from this type of defect. Light of different wavelengths is focused at different positions and focal points
Chromatic aberration
What is “seeing”
It is a measure of the image quality due to the stability of the air
What are CCDs, or charge coupled devices, so useful to astronomical research?
CCDs detect light more efficiently than photographic plates, CCDs provide a precise measurement of changing light intensity across a given area, Images made by CCDs are easily read and manipulated by computer programs—All of these
Radio dishes must be large in order to:
Detect that small amount of radio energy reading Earth
What is the name of the effect when an electromagnetic wave is bent as it passes from one material into another?
Refraction
Which statement about the planet orbits is incorrect?
Most stay close to the Earth’s equatorial plane
Which of these statements is not true of all the jovians?
They all have their poles pointing approximately perpendicular to the ecliptic
Which of the following falls into the category of interplanetary debris?
Large and small asteroids, comets and grains of dust
Which of the following defines density?
Mass Divided by volume
Which statement about density is not correct?
All planet have densities greater than water, at 1 gram/ cc
What is the goal of comparative planetology?
To determine the origin and evolution of the solar system
Our understanding of the solar system has come in a way that can best be described as:
We have learned more in the past few decades than during all of previous history
jovian planets
Uranus SATURN JUPITER NEPTUNE
A gravitational “sling-shot”
Changes the speed and direction of planetary spacecraft as they pass near a planet or moon
Which of the following are terrestrial planets?
Venus, MARS, MERCURY, EARTH Which of the following is NOT a way in which the terrestrial and jovian planets differ? The jovian planets have orbits that are highly inclined to the ecliptic and do not revolve in the same direction as the terrestrial planets
Which of the following has an icy composition?
comets
Where are the asteroids generally found in the solar system?
between the orbits of Mars & Jupiter
What is the name of the NASA probe visiting Comet Wild and returning a sample to Earth?
Stardust
The ESA probe which came the closest to Comet Hally’s nucleus in 1986 was:
GiottoThe NASA orbiter that ultimately landed on the surface of the asteroid Eros was: NEAR Shoemaker
On its way to Jupiter, Galileo also gave us close-ups of
Gaspra & Ida
Before it arrived in orbit about Eros, the NEAR spacecraft also flew past
Mathilde
Large meteoroids are thought to collide within Earth
A few times in every million year period
Iron meteorites are believed to come from
the core of a differentiated asteroid, now broken up
Meteor shower debris is believed to come from:
A broken up cometary nucleus
What part of a comet has only been seen by a space probe?
Nucleus
Compared to Ida, Eros, and Gaspra, what was odd about the density of Mathilde?
It was less dense than rock, but more than ice, suggesting a porous structure
What are comets made of?
Methane, ammonia and water ice, Silica, Metallic dust particles– All of these
The Kulper Belt objects have orbits that:
Stay out beyond Neptune
The Trojan asteroids have orbits that:
Stay sixty degrees ahead of or behind Jupiter
The Apollo and Aten asteroids have orbits that:
Cross the orbit of Earth at perihelion
Long period comets are thought to reside mainly in:
The Oort Cloud
Which of the following objects would be found on the Moon’s surface?
Meterorites
The Oort Cloud is thought to be:
A cloud a comets surrounding the solar system
The orbits of most asteroids:
Lie entirely beyond the orbit of Mars
The orbits of most comets
Lie almost entirely beyond the orbits of Neptune
Which of the following gives direct information about the age of the solar system?
Meteorites
Which of the following objects never collide with the Earth?
Comets, Apollo asteroids, Aten asteroids//None of the above – all can collide with Earth
What causes a meteor shower?
Earth crosses the orbit of a comet, and this orbit is littered with debris
Meteorites are valuable to astronomers because:
They may provde evidence about the process in which the solar system was born
What are Gaspra, Mathilde, Eros and Ida?
Asteroids
The nucleus or main solid body or a comet has a typical size of?
a few kilometers
What is the defining property of the Trojan asteroids?
They have orbits at the distance of Jupiter and 60 degrees ahead of or behind it.
Without a greenhouse effect operating in our atmosphere,
Earth would have an average surface temperature of about -23 degrees Celsius.
What is the best description for the history of the Earth’s rotation?
It is very gradually slowing down about 0.0015 seconds per century
What is the primary ingredient in the Earth’s atmosphere?
Nitrogen
The oldest rocks on Earth are dated to be:
Nearly 4 billion years old
In what part of the atmosphere does life occur?
Troposphere
Name two places on Earth where convection is operating on a large scale, creating natural phenomena that are important features for life on Earth.
In the atomosphere and the mantle
When two tectonic plates collide:
They do not stop moving, but produce large deformations of various types.
In noting that the Earth is “differentiated, we mean that:
The density increases as you descend downward toward the core
The presence of a magnetic field is a good indication that:
A quantity of liquid metal is swirling around in the Earth’s core
If a quarter of the original Uranium 235 atoms have not yet decayed into Lead 207 and U 235 has a half life of about 700 million years, we conclude this igneous rock is about___years old.
1.4 billion
The Earth is about _______ covered in water.
70%
Where is the Sun on September 23?
12 hours RA, 0 degrees declination
Where is the Sun on June 21st?
0 hours RA, +23.5 degrees declination, 12 hours RA, -23.5 degrees declination, 18 hours RA, 0 degrees declination NONE OF THESE ARE CORRECT
Which statement about Right Ascension is false?
It is most like latitude in geography
Where would you be on the Earth if the noon Sun Bassed through your zenith on June 21st?
Tropic of Cancer
Where would you be if Polaris was directly at your zenith?
North Pole
Where on Earth can you observe all the stars in the whole sky over the entire year?
Equator
What phenomena accounts for the 26,000 year wobble which shifts poles and equinoxes?
precession
What celestial line is created by our Earth’s rotation?
Equator
What celestial line is created by our Earth’s revolution around the Sun?
ecliptic
What conditions are necessary for an annular solar eclipse?
new moon near perigee and on the ecliptic
What conditions are necessary for a partial solar eclipse?
new moon near ecliptic, with us in its penumbral shadow
Why is there a two day difference in the sidereal and synodic months?
The Earth has also revolved around the Sun, so the Moon must “catch up.”
A solar eclipse can only happen during a __ moon.
new
A lunar eclipse can only happen during a __ moon.
full
Which statement is about the length of the day is FALSE?
The sidereal day is four minutes longer due to our revolution around the Sun
Which statement about the first quarter moon is FALSE?
To us, it appears one quarter lit
What is parallax?
It is inversely proportional to the object’s distance
If the Moon rose tonight about 6 PM, then tomorrow it will rise about ___.
7PM
What are right ascension and declination?
A means of specifying stars’ locations on the celestial sphere, Analogs of latitude and longitude on Earth’s surface
What is the range of values that the coordinate declination can have?
– 90 to + 90 degrees
How many stars are visible on a clear, dark night with the naked eye alone?
A few thousand.
Scientists today do not believe the Ptolemac model because:
It has been proven to be incorrect.
What is something that is part of both the Ptolemaic and Copernican hypotheses.
The Moon orbits the Earth in a month.
What is one of the contributions made by Copernicus to astronomy.
He said that the Earth is not the center of the universe.
Which concept was NOT part of Ptolemy’s model?
Planets moved in ellipses
Which concept was NOT part of Kepler’s Laws?
Retrograde motion requires epicycles when the planet lies at oppostion, closest to us.
The force of gravity between two objects:
Increases with the mass of the objects and decreases with the distance between them.
Geosynchronous satellites orbit about four earth radii about our equator. There the earth’s gravitaitonal force is how many g’s?
1/16 g
What was not telescopically observed by Galileo?
Saturn’s rings
What was one of Newton’s contributions to astronomy?
He developed a theory of gravity that could explain orbital motion.
On what did Copernicus and Ptolemy agree?
All orbits are circular.
The Ptolemaic model of the universe:
Explained and predicted the motions of the planets with deferents and epicycles.
As Saturn lies at aobut 10 AU from the Sun, out there the Sun’s gravity would be:
100 times weaker
Which of these concepts was not part of the Copernican theory?
Venus must always lie between the Earth and Sun on its epicycle.
What contribution to astronomy was made by Tycho Brahe?
He made extensive and detailed observations of the postitions of the planets.
Upon which point did Kepler and Copernicus disagree?
All planetary orbits must be circular.
By combining Newton’s and Kepler’s Laws, we can weigh the Sun, provided we know:
the size of the AU and the exact length of the year.
Stephan’s Law says:
that the energy radiated by a black body is proportional to T⁴
What is the temperature of water in K (liquid)?
300 K
The frequency at which the intensity of a star’s light peaks depends on the ___ of the star.
temperature
The fact that doubling the star’s surface temperature will halve its peak wavelenght is:
Wein’s Law
What does Wein’s Law reveal?
That the hotter the object, the bluer it’s radiation.
According to Wein;s Law, if the Sun’s surface temperature of 5,800 K doubled:
the peak of its energy would now fall in the ultraviolet part of the spectrum
Which of the following is constant for all types of electromagnetic waves in space?
speed
High-energy astronomers study:
X-rays and gamma rays.
Which of the following types of visible light has the highest energy?
violet
Light waves differ fundamentally from either water waves or sound waves because:
They do not require a material medium.
What is true regarding the Kelvin temperature scale?
Water freezes at 273 K.
If an object is moving toward you, what effect do you observe in the spectrum of that object?
it appears blue-shifted
What is normal body temperature in Kelvin?
310 K
Astronomers believe that the Moon never entirely melted because
Being less massive than Earth, the Moon does not contain enough radioactive elements to heat it to the melting point.
The average rate of erosion on the Moon is far less than that on the Earth because:
The Moon lacks wind and running water