In the Ptolemaic model of the Solar System,
the Earth was .xed and the planets and the Sun moved on epicycles which, in turn, went around the
Mariner 9 was an early space probe sent to orbit
Copernicus said that the rotation of the Earth on its axis caused the
daily motions in the heavens.
Which of the following temperatures is closest to what you might expect on the planet Neptune?
n Newton.s Theory of planetary motion,
the Sun and Earth move around each other.
The arms of a spiral galaxy such as ours stand out because they contain
most of the brightest stars.
Kepler.s Laws of planetary motion were originally obtained by ftting accurate observations. Newton explained those laws by a force that acts on each planet. The force that specifcally explains Keplers Laws
attracts each planet to the Sun.
Which of these planets has a solar day that is shorter than half an Earth day in length?
The Moon rotates on its axis so that it always keeps the same side
toward the Earth.
In addition to being accurate, Tycho Brahe.s observations focused on measuring the positions of the planets
all the time.
A star whose full spectral type is M9V is
a red main sequence star.
The presence of frozen water on Mercury is
possible because it has no axial tilt so that its poles never face the Sun.
ancient greeks had di¢ culty accounting for the motion of a thrown object because they thought that
a force was needed to keep the object moving.
Green plants obtain the energy they need from
In the original Solar Nebula, objects that condensed far from the protoSun tended to include large amounts of frozen gas and water ice because, in that part of the nebula
it was cold enough for gases and water to condense.
A book, weighing 10 Newtons, sits on a table. Which of the following pairs of forces is an action-reaction pair?
The force that the book exerts on the table and the force that the table exerts on the book.
Compared to the Earth, the planet Jupiter is roughly
10 times as large.
The radiant of a meteor shower is the
point in the sky the meteors seem to be coming from.
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. If one object is twice as heavy as the other, Aristotle predicted that
the heavier object would hit the ground long before the lighter one.
The .rst major failure of the Ptolemaic Theory to predict the results of observations was
the phases of Venus.
Spectroscopic Parallax refers to
a method for .nding distances to stars.
When the temperature of a gas decreases, its molecules
An asteroid whose impact generates a planet-wide catastrophe, changing the climate everywhere, probably has a diameter of about
1000 to 10,000 meter
Near-Earth asteroids of the sort that caused the Tunguska blast and the Barringer Meteor Crater are
not likely to be located within the next few years.
Sunlight exerts a force on the sail and moves the spacecraft. Suppose the spacecraft has a total mass of 1000kg (including the sail) and sunlight exerts a total force of 5N on the sail. What will be the acceleration of the spacecraft?
The most second most common element in the universe is
Which of the following types of objects are usually made of rock and iron?
The ancient Greeks were able to calculate the distance from the Earth to the Moon by measuring
how long a lunar eclipse lasts.
According to current theories it seems likely that "rogue planets" or planetary mass objects that are not in orbit around any particular star
exist and may be more common than planets in orbit around stars.
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
Which of the following systems do most living things on Earth now use to reproduce themselves?
Each DNA molecules splits in half and each half acts as a pattern to complete its other half.
Which of the following space probes made detailed three dimensional maps of Venus using radar from orbit around the planet?
The moons of Mars are
not large enough to be spherical.
A star is seen to move by2 seconds of arc between February 1, 1999 and August 1, 1999 and then back to its
starting point on February 1, 2000. What is the parallax angle for this star?
1seconds of arc.
The .rst human landing on the Moon was Apollo 11 in
At present (within the last few hundred years), the distance from the Earth to the Sun
changes enough to make the intensity of sunlight vary by 6 percent.
The stars, as seen from the Earth, appear to be attached to
the Celestial Sphere, a sphere that surrounds the Earth.
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.
You hear a 1000Hz tone from a radio that is 10 feet away from you and listen for 4 seconds. How many pressure maxima pass by your ear?
Here is the Drake Equation:
N= R fp ne f` fi fc L
In this equation,N stands for the
number of communication-capable civilizations in our galaxy.
Information about the structure of the Earth.s interior comes mainly from
Jupiter failed to become a star because
The Sun.s .nal collapse blew all the gas away.
A hydrogen bond is the result of
the electrical attraction between a hydrogen atom on one molecule and an oppositely charged part of another molecule.
The temperature on the surface of Venus is
the highest of any planet in the Solar System.
The mass of Betelgeuse is about 20 times the mass of our own Sun. Our Sun is expected to have a total life span of about 10 billion years. The life span of Betelgeuse is expected to be
The layer of the Earth.s interior that consists of dense, semiliquid material is the
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 period of a proto-star.s evolution when its size and brightness decrease just before the ignition of nuclear reactions in its core is called
the Tau Tauri phase.
Our own Sun has an absolute visual magnitude of 4.8. A starship that travels 10 parsecs from our Sun and looks back at the Sun will see it as having apparent visual magnitude
The Kuiper Belt is the origin of
short period comets.
Uranus rotates on its axis once in about
If you are told that a 20 kilogram object is raised by 10 meters, you know that
the mass of the object is 20 kilograms.
The ecliptic is
the path of the Sun on the Celestial Sphere.
The second space probe to reach the planet Mercury was
As seen from far above the Earth.s South Pole,
no planet orbits the Sun counterclockwise.
The dust tail of a comet
is curved and fuzzy-looking.
The one-wave turning angle of a telescope mirror determines its
di¤raction limit on its resolution.
Compared to the frequency of photons absorbed during a transition from a -5ev state to a -4ev state, transitions from the -5ev state to a -2ev state would correspond to absorbing photons whose frequency is
3 times as high
The reason that the Crab Pulsar is slowing down is
that it is running out of nuclear fuel.
Voyager 2 is the only space probe so far to have visited
The main reason to suspect that Europa has a subsurface ocean of water is
patterns of cracks in the ice on its surface.
water dissolves carbon dioxide and takes it out of the atmosphere.
Current theory says that the Moon formed when
another planet collided with the Earth
Which of the following spacecraft is the only one to have flown past Neptune?
The spacecraft Galileo
went into orbit around the planet Jupiter and dropped a probe into its atmosphere.
The earliest known measurement of the circumference of the Earth used
noon Sun angles at two locations to determine the angle between the Earth radii to those locations.
Cepheid variable stars with the same luminosity usually
have similar periods.
The observed magnetic .eld of Mercury is surprising because it was expected to have
no magnetic .eld at all because it rotates so slowly.
Aristotle pointed out that assuming that gravity pulls everything toward a common center
explains why the Earth is spherical
According to the current de.nition of a planet, Pluto is not regarded as a planet because
it has not cleared its neighborhood of other orbiting objects.
When a star first moves off the main sequence,
its surface temperature drops and its brightness .rst increases and then stays about the same
The stars of the Milky Way are found
in a band of stars stretching across the sky.
If you are looking down over the south pole of the Earth, you will see the Earth rotate
A star is found to have absolute magnitude 9 and apparent magnitude 24. How far away is it?
The layer of the atmosphere that absorbs most of the ultraviolet radiation from the Sun is the
A meteoroid is a medium-sized rock that is
drifting in space.
In the Hertzsprung-Russell Diagram shown, which point represents a star of type B with absolute magnitude
So long as air resistance can be neglected, the most accurate description of the path taken by an artillery shell is
an ellipse with the center of the Earth at one focus.
The idea that a supernova is preceded by a huge burst of neutrinos is
a prediction that has now been observed.
A star at a distance of 1000pc should have an apparent brightness equal to its absolute brightness multiplied by
Type II supernovas have the following properties:
a spectrum with hydrogen lines and a variable maximum brightness.
At the center of our Milky Way galaxy, neighboring stars are typically
much closer together than neighbors of our sun..
Which of the following planets has at least 62 moons?
Our sun is roughly at the center of
the visible part of the Milky Way.
Most Kuiper Belt objects can best be described as
dirty snowballs or possibly flying icebergs.
An atom of ordinary hydrogen consists of an electron and a
The mass of a carbon atom is 12.00amu while the mass of a deuterium atom is 2.014amu. If a gamma ray photon splits a carbon atom into six deuterium atoms, how much energy is converted into mass?
far brighter than typical stars because of their large surface area.
A black hole that has formed from the collapse of a star is expected to be
similar in size to a neutron star.
rotates backwards so that the Sun rises in the West.
Which of the following statements is a speculation (as de.ned in this course)?
There is intelligent life on some other planet somewhere in the universe.
The .rst spacecraft to go into orbit around Saturn was
The rotation axis of Saturn is
inclined at an angle to the perpendicular that is similar to Earth.s rotation axis.
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.
Which of the following planets or moons has an atmosphere whose temperature and pressure permit all three forms of water?
The first generally accepted example of Sea-.oor spreading was under the
Which of the following objects is the largest moon of Saturn?
An arti.cial satellite such as the International Space Station stays up because
the Earth curves out from under it as fast as it falls
The changing phases of the Moon are caused by
the motion of the Moon around the Earth.
Warmer air always.
In the Earth.s atmosphere, the percentage that is Oxygen is roughly
Which of the following spectral types corresponds to the star with the lowest surface temperature?
no ring system at all.
Which of the following magnitudes corresponds to the dimmest star?
What astronomers refer to as a "standard candle" is de.ned as a light source whose
absolute magnitude is known.
Several gases can absorb visible light and re-radiate it as infra-red light. The one that is thought to be most affected by human activities is
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 might consist of rock surrounding an iron core?
Fred reports that a special arrangement of wire coils can draw electrical power from the air. Actually he just
made up that story. Themost likely outcome of his fraud is that:
Other people build the proposed device. They do not see any electrical power, and attack his report as a
mistake or a fraud.
As the two foci of an ellipse are brought together, the shape of the ellipse becomes
more like a circle around the foci.
Compare the magnitude of the acceleration of Earth.s Moon to the acceleration of falling objects on the surface of the Earth.
The Moon.s acceleration is smaller.
An example of a planet which may occasionally have liquid water but retains an atmosphere of mostly carbon dioxide is