Astronomy Final
The diameter of the Milky Way Galaxy is close to
100,000 light years
A star is found to have absolute magnitude 4 and apparent magnitude 24. How far away is it?
100,000 parsecs.
The star 3 -Orionis is 8 parsecs from our Sun. The light from 3 -Orionis has been traveling for
26:4 years
The length of a sidereal month is 27 days. The time from one full Moon to the next is closest to
29.5 days.
Which of the following space probes flew past Saturn but not past Jupiter?
None of these
Which of the following planets or moons has an atmosphere with about 90 times the surface pressure of Earth's.
Venus
An encounter between Earth and an iron asteroid fifty meters in diameter would most likely cause
a large explosion on the ground
When the Earth passes through the orbit of a broken-up comet, we see
a meteor shower
The time it takes for the Celestial sphere to rotate once relative to the Earth is called
a sidereal day
A planetary nebula forms when
a star becomes a white dwarf
An example of a life form that does not get its energy originally from the Sun would be
a tube worm near a black smoker
Because of the electrical repulsion between atomic nuclei, nuclear fusion happens only
at high temperatures
The molecules of both water ice and liquid water are attached to one another by
hydrogen bonds - .Different parts of each molecule have opposite charges
Sedna is thought to be
in the Inner Oort Cloud
The rotation axis of Saturn is
inclined at an angle to the perpendicular that is similar to Earthís rotation axis.
The Russian Venera 9 space probe was sent to Venus, where it
landed on the surface and took pictures
Aristarchus measured the angle between the Sun and the Moon when exactly half of the Moon was illuminated. If the Sun were actually just two or three times as far away as the Moon, he would have found that angle to be
less than 90 degrees by an amount that was easy for him to measure.
Which of the following phases of the Moon would be seen high in the south at dawn?
waning quarter.
The thickest part of the visible Milky Way is near the constellation
Sagittarius
Which of the following temperatures is closest to what you might expect on the planet Neptune?
-350F
Which of the following magnitudes corresponds to the brightest star?
-4:2
The distance modulus of a star at a distance of 10 parsecs would be
0
The Law of Inertia states that a moving object will
keep moving if no force acts on it.
A solar sail is a large sheet of light-reflecting plastic spread on an extremely low-mass framework and attached to a spacecraft. Sunlight exerts a force on the sail and moves the spacecraft. Suppose the spacecraft has a total mass of 2000kg (including the sail) and sunlight exerts a total force of 10N on the sail. What will be the acceleration of the spacecraft?
0.005m/s^2
The mass of a carbon atom is 12.00amu while the mass of a helium-4 atom is 4.003amu. If three atoms of helium fuse to form carbon, how much mass is converted into energy?
0.009amu
In the Earth's atmosphere, the percentage that is water vapor is roughly
1%
The average radius of the Earth's orbit is
1.0 au
Compared to the Earth, the planet Jupiter is roughly
10 times as large.
The density of water is 1000kg/m3, the density of rock is about 3000kg/m3, and the density of iron is 7800kg/m3.Which of the following densities would indicate an object that consists mostly of substances much less dense than rock or iron?
1000kg/m^3
Cruising far from the Sun, we notice that the Sun's apparent brightness has dimmed to 10 watts per square meter. We know that the apparent brightness at a distance of 1au is 1000 watts per square meter. How far from the Sun are we?
10au
At 8pm, you see that the pointer stars of the Big dipper and the star Polaris are arranged in a vertical line. at what time. give or take a minute or so, would you see them arranged at 45 degrees to the vertical?
11:00 p.m. the same day
The velocity of sound waves is roughly the same for all wavelengths. Suppose that a sound wave has a wavelength of one meter and a frequency of 1000Hz. The wavelength of a 500Hz sound wave would then be
2 m
Barnardís Star shows a heliocentric stellar parallax near 1/2 seconds of arc. The distance from our Sun to Barnardís Star is
2 parsecs
The violet lines in the Hydrogen spectrum are normally seen with wavelengths 410nm and 434nm. In the light of a star that is moving toward us, we might expect to see those lines at wavelengths of
400nm and 424nm
What total force will cause an object with a mass of 10kg to gain 5 meters per second every second?
50 Newtons
In the Hertzsprung-Russelll Diagram shown, which point represents a star of type B with absolute magnitude -5?
A
Just before sunrise, you might find
A waning crescent Moon rising in the east
Which of the following statements is falsifiable?
All of the fish in Lake Nyak are green.
Which of the following objects is the most likely to be considered a scientific model?
An accurate map of Richmond.
Underneath the Atlantic Ocean is an undersea mountain range called the MidAtlantic Ridge. That ridge is caused by
An upward current in the Earthís Mante
The first human landing on the Moon was
Apollo 11 in 1969
Suppose that you drop two objects from the same height at the same time. Both objects are heavy enough to be unaffected by air resistance and one object is twice as heavy. Who predicted that the heavier object would hit the ground long before the lighter one?
Aristotle
In the Hertzsprung-Russelll diagram shown, point number 4 could be a
B0 star of absolute magnitude 10
A pair of sugar phosphate chains connected by pairs of nitrogenous bases describes a molecule of
DNA
Which of these moons has patterns of cracks in the ice on its surface. indicating a subsurface ocean?
Europa
Which of the following spectral types corresponds to the star with the highest surface temperature?
F0
Which of the following spectral types corresponds to a star on the main sequence?
G2V
One requirement for a planet to support Earth-type life is that it be considerably larger than Mars. What is the reason for this requirement?
It is necessary for the planet to have active plate tectonics to close its carbon cycle
Joseph Weber designed a series of devices to detect ripples in space-time, called gravitational waves. After several years of effort, Joe announced that he had detected gravitational waves. He built several versions of his devices and they all detected the waves. When other people tried to build similar devices, none of them detected anything at all. Joeís evidence was ignored by the scientific community because
Joe's observations were not reproduced by others
Pioneer 10 was an early space probe sent to fly past
Jupiter
The second space probe to reach the planet Mercury was
MESSENGER
An example of a planet which may occasionally have liquid water but retains an atmosphere of mostly carbon dioxide is
Mars
Which of the following objects has no overall magnetic field except for small regions due to magnetized ore deposits?
Mars
The Asteroid Belt is between the orbits of
Mars and Jupiter
Which of the following statements best describes the presence of water on Mars?
Mars probably had liquid water áowing on its surface at some time in the past
The angle between the rotation axis of a planet and the perpendicular to the plane of its orbit is called its axial tilt.Which of these planets has an axial tilt that is less than one degree?
Mercury
The temperature on Saturn is
Much colder than anywhere on Earth
The capture theory, in which our Moon forms separately and is captured by the Earth, enjoyed a brief popularity when computer models showed that such a capture would have been possible.
The capture theory was dropped because it predicts that the Moon should have hydrated rocks and it does not.
Consider a planet that is similar to Earth in size and Mass with a semiliquid interior. According to our current understanding, which of the following things is also necessary for that planet to have active plate tectonics?
The core temperature should be much higher than the surface temperature
A motorcycle is accelerating from rest. Which of the following pairs of forces is an action-reaction pair?
The force of the motorcycle on the road and the force of the road on the motorcycle
The frequency of a wave is defined to be
The number of crests that pass in one second
Einstein's Theory of Relativity has passed every observational test for over 100 years. Cli§ has analyzed a large family of alternative theories and figured out what each one predicts for the results of observational tests. Cli§ presents his analysis at a scientific meeting. Which of the following would be the most likely reaction of the scientists at the meeting to this new development?
There is great interest because the analysis suggests new tests that could prove that Relativity is wrong, so lots of scientists come to Cliff's talk to congratulate him
Voyager 2 is the only space probe so far to have visited
Uranus
The star Wemadeit shows a stellar parallax angle of 0.4 seconds of arc while the star Waytoofar shows a stellar parallax angle of 0.3 seconds of arc. From this, you can conclude that
Wemadeit is closer to our Sun than Waytoofar
A lunar crater is best described as
a circular ring wall surrounding a flat area
It is expected that a normal Jovian planet, with no accidental encounters that could add or subtract moons, should have
a family of moons, all orbiting in the plane of the planets equator
In addition to being accurate, Tycho Brahe's observations focused on measuring the positions of the planets
all the time
Kepler's First Law of Planetary Motion is that the orbit of each planet is
an ellipse with the Sun at one focus
Kepler's Laws
are explained by a force that attracts each planet to the Sun
The newspaper says that the Moon was full last night. That statement is most likely
based on some authoritative reference such as the U.S. Naval Observatory.
The objects of the Kuiper belt are mostly orbiting
beyond all of the Jovian planets
The Tau-Tauri wind from the Sunís Önal collapse toward ignition
blew away the fuel that Jupiter needed to become a star
A large asteroid impact can a§ect the Earth's climate primarily by
blocking the sunlight with its smoke and dust
The source that is called Sgr A* emits
both infrared light and radio waves
Milankovich cycles refer to
changes in the intensity of sunlight due to shifts in both the Earthís orbit and rotation axis
The Ptolemaic model of the Solar System has each planet moving along a
circular epicycle whose center, in turn, moves around the Earth.
A brown dwarf shines primarily with
energy left over from its formation
The magnetic field of Earth's Moon is
essentially zero
One objection to a solar system model that has the Earth moving around the Sun is that we would then see nearby stars seem to shift back and forth relative to more distant stars. The correct answer to that objection is that
even the closest stars are so far away that the shift is very small
The point at which even an outwardly directed light ray is pulled into a black hole is called the
event horizon
Suppose that the Space Shuttle is in a roughly circular orbit near the surface of the Earth, moving at around 5 miles per second. Suppose the Space Shuttle flips over backwards and Öres its rocket engine to slow its speed to 4.96 miles per second. The shuttle will then
follow an ellipse that descends a bit and then rises again
Supernova explosions tend to
form elements heavier than iron
Carbon is essential for all life we know about because it
forms complex compounds
To measure the heliocentric stellar parallax of a star, you mostly need a telescope with
high resolving power.
The portion of the Earth that is solid iron and nickel is the
inner core
The range of signal frequencies between absorption bands caused by hydrogen and hydroxyl molecules
is referred to as the "water hole" and is the frequency band that SETI programs usually choose
According to the current definition of a planet, Pluto is not regarded as a planet because
it has not cleared its neighborhood of other orbiting objects
The reason that the Crab Pulsar is slowing down is
its magnetic field is dragging through nearby gas
The eclipse or transit photometry method of searching for exoplanets can be expected to find
less than one out of every 10 exoplanets
The motions of the stars near Sgr A* make it possible to determine its
mass
The X-rays that reveal the possible presence of a black hole are the result of
matter heating up as it falls toward the hole
The gravitational energy that is released when the core of a massive star collapses is usually
much larger than the nuclear energy that the star has generated
The main ingredient in the atmosphere of Titan is
nitrogen
The patent for inventing the telescope was obtained by
nobody because it was too simple an idea to patent.
Carbon is
one of the four most common elements in the universe.
Suppose that an asteroid, about 1 kilometer in diameter, shows a 1 in 100 probability of an Earth impact fifty years in the future. Assume that an impact will trigger climate changes that would kill one billion (1,000,000,000) people. Also assume that each of these deaths represents $100,000 in lost production. Using the cold economic logic that we discussed in class, how much money should be budgeted to defect the asteroid?
one trillion dollars ($1,000,000,000,000)
The part of a protostar where the density first becomes low enough for light to escape is called the
photosphere
It has been theorized that planets do not easily form in binary star systems. If they do form, there are three possible arrangements: (1) Planets with orbits similar in radius to the distance between the two stars. (2)Planets with orbits much smaller in radius than the distance between the two stars. (3) Planets with orbits much larger in radius than the distance between the two stars. Observations so far (2009) indicate that
possibilities (2) and (3) actually happen
Which of the following particles would be attracted to a neutron through the strong force?
proton
The role of the DNA molecule in current Earth life is to
provide the patterns for the enzymes that carry out the chemical processes of life
When a red giant star begins to burn helium, it
returns part way to the main sequence in an HR diagram
Planets that are in orbit around stars other than our own Sun are most often found by observing
small changes in starlight due to planetary transits
The idea that science only deals with statements that are falsifiable, subject to possible disproof by observation, suggests that
science produces revisable facts
As seen from North America, the constellation Orion
sets in the west and southwest
Colder air always
sinks.
A full cycle of day and night on Mars is called a ësol.í In terms of 24 hour Earth days, a Martian sol is
slightly longer than one Earth day
The chlorophyll in plants uses sunlight to
split water into hydrogen and oxygen
Consider a light source whose absolute magnitude can be deduced from the properties of the light that reaches us from that source. Astronomers often refer to this sort of object as a
standard candle
In the picture that we used in class, with the Sun above the top of the picture and the Earth shown with its North Pole facing you, the part of the Earth that is to the right of the North pole in the picture is experiencing
sunrise
The term greenhouse effects refers to
the absorption of infrared light by gases in the atmosphere
During the Tau Tauri phase of a protostar's evolution,
the brightness decreases
For an object that is moving along a straight path, the acceleration is
the change in the objectís speed divided by the time it takes
A converging lens will send light rays that are parallel to the axis through
the focal point of the lens
The ecliptic is
the path of the Sun on the Celestial Sphere
Compared to the frequency of photons absorbed during a transition from a from a -6ev state to a -4ev state, transitions from the -5ev state to a -3ev state would correspond to absorbing photons whose frequency is
the same
Pathfinder was the first
to use airbags to land on Mars
A planet that is following Keplerís Laws, accelerates
toward the Sun
The wavelength of the sound waves that correspond to middle-C is about 4 feet. If you are standing 8 feet away from a piano that is playing that note, then between you and the piano there will usually be
two regions of maximum pressure
Astronomy is known for claiming to have measured many things that cannot possibly be probed directly. These measurements are made by combining actual measurements with
well-tested models.
The idea that a worthwhile model of a situation must predict what is actually observed seems to have started
with the ancient Greek philosophers
