Ast 101
Why is dust important to the condensation sequence?
Without dust, there would be nothing for the solar nebula gas to condense onto.
The nucleus of a comet is typically
a few kilometers in size, and very low in density.
Olympus Mons is
a giant mountain on Mars, with a crater at its top.
Galileo found the rotation period of the Sun was approximately
a month
the geological process that we call tectonics refers to __________.
any surface disruption, such as stretching or crumpling, caused by stresses within the interior of the world
Where would you expect terrestrial planets to form in the solar nebula?
anywhere between 0.3 AU and the frost line
1. According to Kepler's second law, Jupiter will be traveling most slowly around the Sun when at
aphelion .
Stellar parallax is the in a star's position with respect to more distant background stars, which occurs as the location of the observer changes.
apparent shift
According to Kepler's second law, as a planet or other object moves around its orbit, it sweeps out equal in equal .
area/times
At these wavelengths, it is necessary to build telescopes with very large light-collecting ______________ to obtain maps of sufficient sensitivity to faint cosmic signals.
areas
Because of their low surface gravities, the Moon and Mercury lack _____.
atmosphere
Which of the following is necessary for erosion to occur on a planet or moon?
atmosphere
The tail of a comet always points
away from the sun and becomes longest and brightest at perihelion
As seen from the Sun's north pole, the Sun and most of the planets rotate _____ on their axis, and the planets orbit _____ around the Sun.
counterclockwise, counterclockwise
_______ are bowl-shaped depressions on the surface of a planet or moon, resulting from acollision with interplanetary debris.
craters
Which of the following are found on the surface of Mercury?
craters and scarps
Astronomical observations at these wavelengths can be obtained even during
storms
The design of modern X-ray telescopes depends on
grazing incidence optics.
____________refers to the loest energy state that an elctron can have within an atom
ground state
Consider a planet with an elliptical orbit around the Sun. Its average distance from the Sun is
half the distance along a line from the nearest to the farthest points in its orbit
Exoplanets known as super-Earths
have masses 2-10 times that of Earth.
According to Kepler's third law, if two planets (with different orbital distances and different masses) are orbiting a star of the same mass __________.
he planet with the greater distance will take longer to complete an orbit
One advantage of the Hubble Space telescope over ground based ones is that
in orbit, it can operate close to its diffraction limit at visible wavelengths.
If you had only one telescope and wanted to take both visible-light and ultraviolet pictures of stars, where should you locate your telescope?
in space
What substances were found within the inner 0.3 AU of the solar system before planets began to form?
rocks, metals, hydrogen compounds, hydrogen, and helium, all in gaseous form
are features believed to be the result of cooling and shrinking of the crust forming a wrinkle on the surface.
scarps
1. The mathematical form of Kepler's third law measures the period in years and the ________ in astronomical units (AU).
semimajor axis
Which of these is the same for all forms of electromagnetic (E-M) radiation in a vacuum
speed
if two objects of the same mass are attracting each other gravitationally, what happens to the strength of gravity if you double the distance between them?
The force of gravity decreases by a factor of four
If the distance beween the centers of two objects doubles, what happens to the gravitational pull between them if the masses do not change?
The force will decrease to one-fourth its previous size
During the time that a comet passes through the inner solar system, the comet can appear quite bright because __________.
sunlight reflects off the comet's tail and coma
How long would a radar signal take to complete a round-trip between Earth and Mars when the two planets are 1.0 AU apart?
t=1000 seconds
In composition, the _____ planets have rocky materials like the asteroids
terrestial
Which of the following is NOT a property of our solar system we must account for in a theory of its origin?
the Earth is the only planet that is known to have life.
Consider Earth and the Moon. As you should now realize, the gravitational force that Earth exerts on the Moon is equal and opposite to that which the Moon exerts on Earth. Therefore, according to Newton's second law of motion .
the Moon has a larger acceleration than Earth, because it has a smaller mass
The major axis for a particular planet is known. In order to determine the perihelion and the aphelion, what other information about the planet is needed?
the eccentricity of the orbit
A major advantage of a Newtonian reflector over a refractor is
the elimination of chromatic aberration.
Mercury's long, tall cliffs are thought to have formed when
the entire planet shrank, causing the surface to crumple.
the total energy radiated by a blackbody depends on
the fourth power of its temperature
Remember that Doppler shift tells us the star's velocity, and the star is moving around the center of mass of the system in response to the gravitational tug of the planet. Therefore, the star with the largest Doppler shift will be __________.
the one experiencing the strongest gravitational force
The force of gravity follows an inverse square law, meaning that the strength of the force declines with the square of the distance between two masses. But if the distances between pairs of objects are all the same, as in Part A, then the strength of gravity depends only on .
the product of the two object masses (M1 × M2 )
As white light passes through a prism, the red (longer) wavelengths bend less than the blue (shorter) wavelengths, so forming the rainbow of colors
true
Barringer Crater in Arizona is an example of a meteorite impact.
true
Craters can hold evidence for past liquid water?
true
Due to our ozone layer, ultraviolet astronomy must be done from space
true
If a fire truck's siren is rising in pitch, it must be approaching us
true
Mars has the largest volcanoes in the solar system.
true
Mercury's magnetic field is generated by the same dynamo effect as Earth's.
true
Optical telescopes are usually used only at night, but radio telescopes can be used day or night.
true
Radio telescopes have poorer angular resolution than optical telescopes because radio waves have a much longer wavelength than optical waves.
true
Some meteorites are believed to have come from Mars and the Moon.
true
The light-gathering ability of a telescope is most dependent on the diameter of its primary objective.
true
The simplest reflector telescope design is the prime focus reflector.
true
There is evidence of recent water erosion on Mars.
true
Venus' rotation period is longer than its period of revolution around the Sun.
true
Winds on Mars give rise to planet-wide dust storms.
true
as they move through space, the vibrating electrical and magnetic fields of a light wave must move perpendicular to each other.
true
What problem does adaptive optics correct?
turbulence in the Earth's atmosphere that creates twinkling
Telescope X has a single 1-meter mirror, and Telescope Y has two 1-meter mirrors that work together. Telescope Y therefore has ______ the light-collecting area of Telescope X.
twice
A dense, hot body will give off a(n) _____ spectrum.
continuous
Mercury presents the same side to the Sun
every other orbit.
__________ refers to the state on an atom when one of its elctron sis in a higher energy orbital than the ground state
excited state
A Newtonian reflector needs no secondary mirror.
false
A telescope with an 8-inch mirror will collect twice as much light as one with a 4-inch mirror.
false
All the planets revolve around the Sun in the same direction, except for Venus and Uranus.
false
Atmospheric pressure on Mars is roughly half that of Earth's at sea level.
false
Canyons on planetary surfaces are always produced by the flow of water?
false
Gamma-ray telescopes employ the same basic design that optical instruments use
false
If a new wave arrives on shore every two seconds, then its frequency is 2 Hz.
false
In blackbody radiation, the energy is radiated uniformly in every region of the spectrum, so the radiating body appears black in color.
false
Kepler's third law allows us to find the average distance to a planet from observing its period of rotation on its axis.
false
Most comets have short periods and orbit close to the ecliptic plane.
false
Running water continues to be the major erosive factor of Mars today.
false
The Earth's atmosphere is the major factor limiting the use of ground-based radio telescopes.
false
The Hubble Space Telescope gives us its best resolution with X-rays.
false
The larger the red shift, the faster the distant galaxy is rushing toward us.
false
The opacity of the atmosphere is partially corrected via adaptive optics.
false
The term seeing is used to describe how faint an object can be detected by a telescope.
false
True or false, after investigating a great many features on the surface of Mars, we can say that all Martian geology, other than impact cratering, is deep in the past.
false
Wave energy can only be transmitted through a material medium.
false
true or False? All forms of light easily travel through Earth's atmosphere to the ground.
false
Consider two triangles that represent the swept-out area in some time period as an object orbits the Sun. If one triangle is short and squat (where the object is close to the Sun) and the other is long and thin (where the object is far from the Sun), then the object must have moved .
farther in the case where the triangle is short and squat
earth is located at one_________ of the moons orbit
focus
A comet entering the inner solar system from afar will __________.
form a coma and some time later form a tail
The number of waves that pass a point each second measures ________.
frequency
Which planet shows the widest range of surface temperatures between day and night?
mercury
Venus's surface is permanently obscured by clouds. As a result, the surface has been studied primarily by
orbiting satellites using radar.
1. According to Kepler's second law, Pluto will be traveling fastest around the Sun when at
perihelion
When a planet's orbit takes it closest to the Sun, it's called
perihelion
These two photos show the same region of space. One of them is taken in visible light. Note that stars are obscured in Photo 2 but are much easier to see in Photo 1. Considering the properties of the different bands of the electromagnetic spectrum, which spectral region do you think was used to take each photo?
photo 1 infared photo 2 visible
Which type of telescope has the simplest light path?
prime focus reflector
When identifying the element classification of a particular atom, which type of subatomic particle is used?
proton
The age of the solar system is determined with _____ dating.
radioactive
As telescopes become larger and larger, astronomers favor ________.
reflecting telescopes, in part because large lenses and mirrors sag under their own weight, and it is easier to support a mirror along its entire back side than it is to support a lens only around its edge
he Kuiper belt and Oort cloud can be described as __________.
regions from which comets enter the inner solar system
the rock/metal condensation line marks the innermost boundary where __________.
rock or metal could condense into solid flakes
For terrestrial planets to form __________.
rocks and metals must be present as solid flakes
The jovian planets are thought to have formed as gravity drew hydrogen and helium gas around planetesimals made of __________
rocks, metals, and ices
What seems to be the most common feature of the landing sites of the various Mars missions?
Evidence for water at some point in Mars' history
While gravity is always attractive, electromagnetic forces are always repulsive.
False
Newton's second law of motion states that force equals mass times acceleration, or F=ma. Suppose you have already calculated the gravitational force, which we will call Fg , attracting Earth and the Moon. Then the amount of acceleration of Earth due to this force is .
Fg divided by the mass of the Earth
Why were Martian volcanoes able to grow so large?
Mars's weaker surface gravity
he terrestrial planets in our solar system are __________..
Mercury, Venus, Earth, and Mars
Which of the following is true about observations at wavelengths other than optical or radio?
Most observations at wavelengths other than optical or radio need to be conducted by space-based telescopes.
Galileo was the first to observe planets visible to the naked eye with a telescope. Which planets did Galileo not observe with his telescope?
Neptune, uranus
Kepler's third law is best expressed as .
P 2 ~ a 3
Consider the figure below and determine which characteristics of the solar system it illustrates.
Planets orbit in the same direction as the Sun rotates on its axis. Mostly the direction of planetary rotation is the same as the direction of the Sun's rotation. Mostly satellite orbital direction is the same as the satellites' parent planet rotational direction.
What is the name given to the phenomenon in which the apparent motion of the superior planets sometimes reverses
Retrograde motion
What two measurable properties directly tell us the size and shape of a planet's orbit?
Semimajor axis and eccentricty.
According to Newton, the gravity of the is needed to explain planetary orbits.
Sun
Assuming that other planetary systems form in the same way as our solar system formed, where would you expect to find terrestrial planets?
Terrestrial planets will likely be located nearer the planetary system's star than any jovian planets.
it is thought that Mars used to have running water on the surface. Which of the following are necessary consequences of that idea?
The atmosphere used to be thicker. The temperature used to be warmer.
According to Newton, planets orbit in ellipses with what at the two foci?
The center of mass and nothing
According to Newton's second law, the greater the force exerted on an object, the greater the object's .
acceleration
What kind of spectrum does the Sun have?
an absorption spectrum
Which of the following statements are true?
-Infrared is named for the part of the spectrum with frequencies less than those of red light. -Ultraviolet is named for the part of the spectrum with frequencies greater than those of violet light. -Visible is named this because we can see these waves.
List the major facts that any theory of the solar system formation must explain, and indicate how the leading theory accounts for them.
-Planets orbit with nearly circular orbits. -Planets are comparatively isolated in space. -A collection of asteroid-sized objects orbits beyond Neptune in the Kuiper belt.
Which of the following is/are true when comparing radio telesopes to optical telescopes?
-radio telescopes can observe objects in the daytime -radio telescopes can observe objects even when it's cloudy
the light-collecting area of an 8-meter telescope mirror is _____ that of the light-collecting area of a 2-meter telescope.
16 times
If the photographic plate records 5 percent of the light reaching it, and the CCD records 90 percent, how much time will the new system take to collect as much information as the old detector recorded in a 5 hr exposure?
17 min
the Sun's tidal pull has slowed Mercury's rotation down to a period _____ that of its year.
2/3
Electrons can absorb energy either from light radiation or from collisions with other atoms. If an electron is in the first excited energy state and absorbs enough energy to go to the next higher energy state, into what state will the electron transition?
2nd excited state
The major axis for a new comet has been determined to be 100 AU. The eccentricity of the orbit was measured to be 0.94. What is the distance of closest approach to the Sun for this comet?
3 AU
Normal human body temperature is about 37∘C. What is this temperature in kelvins? What is the peak wavelength emitted by a person with this temperature? In what part of the spectrum does this lie?
310 K 9.4 UM infared
What is the approximate age of the solar system, according to the best available scientific evidence?
4.6 billion years
How long does a radar signal take to travel from Earth to Mercury and back when Mercury is at its closest point to Earth?
610 seconds
What is the surface gravity on Mars compared to that of Earth? What would a 74 kg person weigh on Mars?
9m/9e - 39% Wm=283N
Many bodies in the solar system, both moons and planets, have atmospheres that surround their surfaces. These atmospheres are composed of cool gases that have low densities compared to their surfaces. When astronomers observe these planetary bodies, they really are observing light coming initially from the Sun, which is reflected by the planetary atmosphere. When sunlight reflects from a cool, low-density gas, what type of spectrum would you expect to observe?
Absorption spectrum
The Sun is the brightest light in Earth's sky because it is the nearest star. Most of the light is generated by the hot, very dense, inner layers of the Sun. However, the light reaching Earth must travel through the cooler atmosphere of low-density gas that surrounds the Sun. Based on these two components of the Sun, what type of spectrum is the Sun observed to have here on Earth?
Absorption spectrum
All but one of the following have been observed on Venus and provide evidence of volcanic activity there. Which one has NOT been observed?
Actively erupting volcanoes
Which of the following features on Mars is/are volcanic in origin?
Alba Mons
Water is one of the most common substances in the universe, and vital to us on Earth.
At first, while erupting volcanoes thickened it, Mars' atmosphere was dense enough to stay warm enough for liquid water to flow over much of Mars' ancient surface. But as the core of Mars cooled down, volcanism declined, and Mars' atmosphere lost much of its initial water to space, due to it less surface gravity then our own. Today there is still much water frozen in the polar caps and tundra, and on some occasions it melts fast enough to erupt as small mud flows imaged by the Mars Global Surveyor recently.
Which of the following statements about comets is incorrect?
At its largest, the coma is roughly 10 times bigger than the nucleus of the comet itself.
The dwarf planet Eris was discovered in 2005, orbiting the Sun at an average distance about twice that of Pluto. In which of the following ways do Pluto and Eris differ from the terrestrial and jovian planets in our solar system?
Both Pluto and Eris are smaller than any of the terrestrial planets. Both Pluto and Eris travel in more elliptical orbits than any of the terrestrial or jovian planets Both Pluto and Eris are less massive than any of the terrestrial or jovian planets.
Mars and Earth are similar in many ways and different in others. Which of the following is NOT one of the ways in which they are similar?
Both have similar densities.
What material is rare in the atmosphere of Earth, but common in the atmospheres of Mars and Venus?
Carbon dioxide
What caused the scarps found on Mercury?
Cooling of the planet and shrinking of the crust
What is the main reason that ultraviolet astronomy must be done in space?
Earth's atmosphere absorbs most ultraviolet wavelengths.
Emission and planetary nebulae are clouds of glowing, hot gas, primarily hydrogen, with very low densities. Thus, both of these types of nebulae produce the same type of spectrum. What type of spectrum is produced by a low-density, hot, hydrogen gas?
Emission spectrum
Many comets reside in the Oort cloud at a great distance from the Sun. Some of these comets have orbits that take them into the solar system, sometimes in the neighborhood of Earth, for brief intervals. What type of orbit must a comet have to enter the solar system?
Highly elliptical
What was the cause of the Caloris Basin?
Impact of a large asteroid
Astronomical sources emit electromagnetic radiation at various wavelengths. Some sources might emit just visible and infrared radiation. Other sources might emit gamma, UV, visible, and infrared radiation. Some of that radiation travels in the direction of Earth and can be detected with the right telescopes placed in the right locations. Some wavelengths can be read in the atmosphere. However, the majority of wavelengths are either read from space or Earth's surface. Which observations would require you to launch a telescope above the Earth's atmosphere? Please drag each observing mode below into either the ground-based (Surface) zone or space-borne (Space) zone, depending on the respective observing requirements.
Intermediate-wavelength radio (10 m to 1 cm wavelength) Visible (Optical) (700 to 400 nm wavelength) Near-infrared (10 μm to 0.7 μm wavelength)
What is the source of Mars's red color?
Iron oxide in the soil
What is true of Mars?
Iron oxide on the surface is responsible for its reddish color.
The force of gravity between two objects obeys which of the following relationships?
It is attractive and increases if their masses increase
The lack of any significant magnetic field on Venus probably is due in part to which of the following characteristics?
Its slow overall rotation
Galileo Galilei was the first scientist to perform experiments in order to test his ideas. He was also the first astronomer to systematically observe the skies with a telescope. Galileo made four key observations that challenged the widely accepted philosophical beliefs on which the geocentric model was based, thus providing support for the heliocentric model. From the following list of observations, which are the key observations made by Galileo that challenged widespread philosophical beliefs about the solar system?
Jupiter has orbiting moons. The Moon has mountains, valleys, and craters. Venus goes through a full set of phases. The Sun has sunspots and rotates on its axis
Johannes Kepler used decades of Tycho Brahe's observational data to formulate an accurate description of planetary motion. Kepler spent almost 30 years of his life trying to develop a simple description of planetary motion based on a heliocentric model that fit Tycho's data. What conclusion did Kepler eventually come to that revolutionized the heliocentric model of the solar system?
Kepler determined that the planetary orbits are elliptical.
's theories were based on the very accurate observations made by
Kepler, Tycho Brahe
Which of the following objects or regions is the furthest from the Sun?
Kuiper Belt
Which of the following is a trend that we see in the extrasolar planet systems we have discovered?
Many of the new planets are within 1 AU of their star.
Why do we think that Mars has significantly less metal in its core than the Earth does?
Mars has a lower overall density than Earth. Mars has a weak magnetic field, despite its relatively rapid spin. Mars has a great deal of rusted iron on its surface. All of the above are evidence.
Why are Mars' seasons more extreme than those of the earth?
Mars' weather is affected by evaporation from the polar ice in its summer. Mars' orbit is more eccentric than our almost circular one. Mars' axial tilt is slightly more than our 23.5 degrees. Mars' seas dried up long ago. All of these contribute to the huge seasonal changes that Mars experiences.
The planets of the inner and outer solar system are highly differentiated. There is a relative lack of light elements such as hydrogen and helium in the inner solar system, while light elements are common in the outer solar system. Which of the following statements explains this differentiation?
The intense heat in the center of the solar nebula prevented light elements like hydrogen and helium from condensing in the inner solar system.
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.
Suppose two cars both drive for one hour. Which statement is true?
The one that goes faster travels farther
Suppose Earth doubled in mass. How would Earth's orbital period around the Sun change?
The orbital period would remain exactly one year
The atom consists of three types of subatomic particles: protons, neutrons, and electrons. The electron is by far the lightest of the three, while the much heavier proton and neutron have masses very similar to each other. Two of the types of particles carry an electrical charge, while the third is neutral. Label the subatomic particles and appropriate charges by their relative locations.
The proton carries a positive charge. The electron carries a negative charge.
Which of the following was NOT one of the discoveries made by Galileo?
The shape of a planet's orbit is an ellipse.
Which of the following is the best description of our knowledge of the surface of Venus?
The surface is extremely dry, with evidence of past volcanic events.
Which statement about asteroids is not true?
Their images become blurry due to outgassing as the Sun heats them up.
Which statement is true of Venus' surface?
There are two continent sized uplands.
Now that we are aware that asteroids cross Earth's orbit, detecting them has become important. Why are they so difficult to detect if they are crossing Earth's orbit?
They are relatively far away. They are small. They are not very reflective. All of the above.
Which statement best describes the shield volcanoes on Venus?
They are wider than they are tall.
What is true of radio telescopes?
They have poorer angular resolution than a refractor of the same size.
Asteroids that cross Earth's orbit may eventually collide with Earth. If that were to happen, what could be the result?
They would be destroyed in Earth's atmosphere. They would make huge impact craters. They would kill all life on Earth.
The observed spectral lines of a star are all shifted towards the red end of the spectrum. Which statement is true?
This is an example of the Doppler effect.
Astronomers have made many observations since the days of Galileo and Kepler to confirm that the Sun really is at the center of the solar system, and that the planets revolve around the Sun in elliptical orbits. Which observation(s) could you make today that Galileo and Kepler could not have made to confirm that the heliocentric model is correct?
Transit of an extrasolar planet Doppler shifts in stellar spectra of nearby stars Stellar parallax in nearby stars
Which planet is approximately halfway between Pluto's orbit and the Sun?
Uranus, the seventh planet from the Sun
Which of the following locations does not show direct evidence of a liquid water past on Mars?
Valles Marineris
Copernicus' Heliocentric theory explains that
Venus retrogrades when she overtakes us at inferior conjunction.
For a wave of constant velocity, such as an electromagnetic wave, how are the wavelength and frequency related?
Wavelength is inversely proportional to the frequency.
Kepler's third law states that for any planet orbiting the Sun, the orbital period squared (p2 ) is equal to the average orbital distance cubed (a3 ), or p2 = a3 . This implies that .
a planet with a large average distance from the Sun has a longer orbital period than a planet with a smaller average distance from the Sun
Kepler's third law states that for any planet orbiting the Sun, the orbital period squared (p2 ) is equal to the average orbital distance cubed (a3 ), or p2= a3. Thisimpliesthat.
a planet with a large average distance from the Sun has a longer orbital period than a planet with a smaller average distance from the Sun
Kepler's third law states that for any planet orbiting the Sun, the orbital period squared (p2 ) is equal to the average orbital distance cubed (a3 ), or p2= a3 . Thisimpliesthat.
a planet with a large average distance from the Sun travels at a slower average speed than a planet with a smaller average distance from the Sun
At these wavelengths, it is necessary to build telescopes with very large signal-sensing ____________ to obtain maps of sufficient detail.
baselines
The asteroid belt is located __________.
between Mars and Jupiter
showing the motion of a ball near Earth's surface, depicts how gravity
causes the ball to accelerate downward.
The solar system models developed before Kepler's time assumed that the planets followed
circular orbits
The primary purpose of a telescope is to
collect a large amount of light and bring it into focus.
What is the source of the material of a meteor shower?
comets
The Andromeda galaxy lies about 2.5 million light-years away. To what distances do the angular resolutions of SST (3″), HST (0.05″), and a radio interferometer (0.001″) correspond at that distance?
dSST = 36 light-years dHST = 0.61 light-years dradio interferometer = 1.2×10−2 light-years
The effect of a cool, dilute gas between an observer and a continuous hot source is that ________.
dark absorption lines will appear in the spectrum
If our eyes were sensitive only to X rays, the world would appear __________.
dark because X-ray light does not reach Earth's surface
For the situations shown, the two objects we are concerned with are Earth and the spaceship, which both have constant masses. Therefore, the strength of gravity between them: .
decreases with the square of their distance apart
For the situations shown, the two objects we are concerned with are the Moon and the spaceship, which both have constant masses. Therefore, the strength of gravity between them .
decreases with the square of their distance apart
What kinds of planets are expected to form close to the Sun?
dense, rocky planets
f you want to make a very dim object appear much brighter in an image photographed through a telescope, which of the following factors are important?
diameter of the telescope and the length of the exposure
Which of the following methods is the most difficult way to search for planets around other stars?
directly imaging the planets and watching their orbits
The extent to which Mars' orbit differs from a perfect circle is called its
eccentricity
Protons and electrons carry equal but opposite charges. Atomic nuclei are positively charged and are not composed of negatively charged particles. Which types of subatomic particles cannot be located within the nucleus?
electrons
1. Earth orbits in the shape of a/an_______ around the Sun.
ellipse
These two photos were taken at the same time and same location near San Jose, California. The one on the left was taken using visible light. Considering the properties of the other parts of the electromagnetic spectrum, which type of radiation do you think was able to penetrate the dust and smog to obtain the image on the right?
infared
The James Webb Space Telescope is designed primarily to observe __________.
infared light
______ are regions on the surface of Mercury that do not show extensive cratering but are relatively smooth.
intercrater plains
Radio astronomers have pioneered the use of multiple telescopes working in concert that can produce maps of radio emission as detailed as optical images. These arrays of multiple telescopes are known as
interferometers
A comet's plasma tail consists of _____.
ionized gas
Venus' rotation on its axis
is clockwise, unlike most other solar system objects.
Earth emits thermal radiation, which means it has a spectrum that __________.
is continuous with a peak at a wavelength determined solely by Earth's surface temperature
the atmospheric pressure on Venus
is much higher than on Earth.
Copernicus proposed a heliocentric model for the solar system primarily because
it was much simpler than the Ptolemaic model
What is the resolution of a telescope?
its ability to distinguish two adjacent objects close together in the sky
The two factors that determine how well a telescope with a particular camera can detect dim galaxies are __________.
light-collecting area and exposure time with the camera
In our solar system, terrestrial planets are __________.
located closer to the Sun than jovian planets
Valles Marineris is
long system of canyons stretching nearly a fifth of the way around Mars, looking much like a set of giant cracks in the surface.
_____are relatively dark-colored and smooth regions on the surface of the Moon.
maria
Which of the following properties of a star CANNOT be directly determined from its spectrum?
mass
In general, the spectral lines of molecules are
more complex than those of atoms.
Compared to terrestrial planets, jovian planets are __________.
more massive and lower in average density
What are most meteorites made of?
mostly rock
What features on Mars tend to be the most obvious indication of volcanic activity?
mountains
To calculate the gravitational force between two objects we , and then multiply by the gravitational constant G.
multiply the two masses, divide by their distance squared
According to Kepler's second law, planets and other objects orbiting the Sun move fastest when they are
nearest to the Sun
Planets move in orbits around the Sun that are __________ in shape.
nearly circular
What substances exisited as solid flakes within the inner 0.3 AU of the solar system before planets began to form?
none
A comet's plasma tail always points directly away from the Sun because __________.
of pressure exerted by the fast-moving charged particles in the solar wind
Meteors can be viewed only __________.
on worlds with atmospheres
In Bohr's model of the atom, electrons
only make transition between orbits of specific energies
Medium A blocks more of a certain wavelength of radiation than medium B. Medium A has a higher
opacity
is another term for any precisely defined energy state in which an electorn can exist in an atom
orbital
The time a planet takes to complete one orbit is called its
orbital period
According to Newton's third law .
the strength of the force that the object on the left exerts on the object on the right has to be exactly the same (but in an opposite direction) as the force the object on the right exerts on the object on the left
the highest-frequency reflected radiation is received from
the upper part of the planet
What will happen to the absorption and/or emission spectral lines of an object moving away from Earth at high speed?
they will be shifted toward the red end of the spectrum.
If a star was the same size as our Sun, but was 81times more luminous, it must be
three times hotter than the Sun
A blue star has a higher surface temperature than a red star.
true
According to Copernicus, retrograde motion occurs at opposition for the outer planets
true
According to Newton's second law, if you double the force acting on a body, the acceleration will double.
true
All the terrestrial planets lie inside the asteroid belt.
true
Although it has no liquid water, Mercury has a tidal bulge.
true
An emission line results from an electron falling from a higher to lower energy orbital around its atomic nucleus.
true
As a rotating gas cloud contracts, it spins faster.
true
Consider two identical stars, each with a planet at the same distance of 1 AU. If the planet orbiting Star A is twice as massive as the planet orbiting Star B, the gravitational force between star and planet is __________.
twice as much for Star A as for Star B
If we were to construct an accurate scale model of the solar system on a football field with the Sun at one end and Neptune at the other, the planet closest to the center of the field would be
uranus
Pioneer Venus observed high-level clouds moving around Venus's equator in 4 days. What was their speed in km/h? What was their speed in mph?
v = 400 km/h v = 250 mph
the planet _____ has the least variation in temperatures on the surface between day and night.
venus
Which of the following forms of light can be observed with telescopes at sea level?
visible radio
Which of the following types of electromagnetic waves has the shortest wavelength?
x ray
In the Kelvin scale, absolute zero lies at
zero K