PHYS 103 FINAL REVIEW (Groupme)
Which of the following temperatures is closest to what you might expect on the planet Jupiter?
-250°F
Which of the following temperatures is closest to what you might expect on the planet Uranus?
-350°F -Obviously, as the planets get farther from the Sun the temperatures will get colder
Which of the following temperatures is closest to what you might expect on the planet Neptune?
-350°F (same as Uranus)
The number of moons of Uranus that are larger than Earth's Moon is
0
An ion rocket engine produces 10 Newtons of thrust. What acceleration can it give to a space probe with a mass of 1000kg?
0.01m/s^2 -a = F/m
The closest star to our sun is about four light years away. In the center of our galaxy, a typical distance between neighboring stars would be
0.04 light years
As of 2018, how many space probes had flown past Uranus closely enough to take detailed pictures?
1
As of 2018, how many space probes have flown past Neptune closely enough to take detailed pictures?
1
both its magnetic poles remain almost motionless at its geographic poles How many of the moons of Saturn are larger than the Earth's Moon?
1
A star is seen to move by 2 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?
1 second of arc
How many stars similar to our sun would need to be collected at one place to equal the power output of Sgr A*?
1,000,000
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 250Hz. The wavelength of a 1000Hz sound wave would then be
1/4m
In addition to measuring the positions of all the planets all the time, Tycho Brahe measured them to an accuracy of
1/60 degree of arc
A starship observes that a nearby star has apparent magnitude 4.0. The spectrum of the star indicates that it is a type that normally has absolute magnitude 4.0. From these observations, the starship knows that it is
10 parsecs from the star
The apparent brightness of our Sun is roughly 1000 watts per square meter. Saturn is at roughly 10 astronomical units from our Sun (slightly less actually). Viewed from Saturn, the apparent brightness of our Sun would be
10 watts per square meter
The diameter of a white dwarf star might be
10,000 miles
A star is found to have absolute magnitude 9 and apparent magnitude 24. How far away is it?
10,000 parsecs
A star is observed to have an apparent brightness which is 10⁻⁴ times its absolute brightness. How far away is it?
1000 parsecs
Barnard's star is a near neighbor of the Sun whose properties we know quite well. It is a type M4V with absolute magnitude 13.22. Suppose that another star of spectral type M4V is observed to have apparent magnitude 23.22. How far away is it?
1000 parsecs
Suppose that the color and behavior of a star identify it as a type that we know has absolute magnitude 4.8. If the star's apparent magnitude is found to be 14.8, how far away is it?
1000 parsecs
Suppose that a flash of lightning from a cloud 2000 meters away is followed by a clap of thunder two seconds later. Assume that the light arrived in a negligible time and calculate the speed of the sound waves.
1000m/s
The time it takes for Jupiter to travel once around the Sun is closest to
12 Earth years
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 is closest to the average density of Jupiter?
1200kg/m³
The asteroid 2008 AF4 has one chance in 21,000 of hitting the Earth between the years 2078 and 2100. The asteroid is 390 meters in diameter compared to 250 meters in diameter for Apophis. Assuming that an impact could cause the death of 30,000,000 people the average death rate for this type of event is approximately
1500 people per event
At 10pm, 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?
1:00 a.m. the next day - 45 degrees = +3 hours, so 10pm → 1am
Compared to the frequency of photons absorbed during a transition from a -6ev state to a -4ev state, transitions from the -6ev state to a -2ev state would correspond to absorbing photons whose frequency is
2 times as high
Which of the following time periods is closest to the time from a New Moon to the next Waning Quarter Moon?
22.5 days
The light of a star that is 8 parsecs away has been traveling for
26.4 light years -1 parsec = 3.3 light years, so 8 x 3.3 = 26.4
The distance from our sun to the center of the Milky Way Galaxy is roughly
30,000 light years
The inclination angle of a planet's rotation axis is defined so that a planet that is rotating in the usual direction about an axis that is perpendicular to the plane of the solar system would have an inclination of 0°, while a planet that is rotating in the opposite (retrograde) direction about an axis that is perpendicular to the plane of the solar system would have an inclination angle of 180°. The inclination angle of the planet Neptune is closest to
30°
What total force will cause an object with a mass of 10kg to gain 5 meters per second every second?
50 Newtons -Force = mass x acceleration (F = ma)
Which of the following temperatures would be most likely at noon on the hottest day of the year in the warmest part of Mars?
50° F
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 is closest to the average density of the Earth?
5200kg/m³
At which of these times of day would you expect to find the Sun in the East?
6:00am
The star Vega is 25 parsecs from our Sun. The light from Vega has been traveling for about
80 years
The inclination angle of a planet's rotation axis is defined so that a planet that is rotating in the usual direction about an axis that is perpendicular to the plane of the solar system would have an inclination of 0°, while a planet that is rotating in the opposite (retrograde) direction about an axis that is perpendicular to the plane of the solar system would have an inclination angle of 180°. The inclination angle of the planet Uranus is closest to
98°
A galaxy of Hubble type SBa is
A barred spiral galaxy with a large central bulge
A star that is named Epsilon Eridani is most likely
A fairly dim star in the constellation Eridanus
A disadvantage of the gravitational tractor approach to deflecting an asteroid is that
A massive spacecraft is needed
Aristarchus of Samos is known for a number of things. One of them was
A model in which the Earth rotates on its axis and revolves around the Sun
Which of the following objects is closest in size to a black hole formed from the collapse of a star?
A neutron star
A steady X-ray signal with sudden bursts lasting a few seconds each is probably caused by
A neutron star in a binary system
Kuiper Belt
A region of the solar system that is just beyond the orbit of Neptune and that contains small bodies made mostly of ice
The time it takes for the Celestial sphere to rotate once relative to the Earth is called:
A sidereal day
A type E0 galaxy would be
A spherical galaxy
A type Ia supernova occurs when
A white-dwarf begins to collapse
Which of the following models for the formation of life on Earth would most likely apply if it turns out that the first step of forming a self-copying molecule is rather easy and happens as soon as conditions are right for it?
Abiogenesis Model
A star that evolves off the main sequence in about 10 million years probably has
About 20 times the mass of our Sun
The absence of a magnetic field of Venus is
As expected because the planet rotates so slowly -Magnetic fields are created by liquid metal cores of planets, so a planet that doesn't rotate very fast will not have much of a magnetic field
Which of the following types of objects can be made of rock and iron?
Asteroids
An average star that is farther out from the galactic center than our sun would most likely be moving
At about the same speed as our sun
Think of the 'front' of a telescope as the end that light enters. A telescope with Cassegrain Focus has the eyepiece
At the back of the telescope
The first generally accepted example of Sea-floor spreading was under the
Atlantic Ocean
When nuclear fusion reactions stop in a star similar to our own Sun, the star
Becomes a white dwarf
The source that is called Sgr A* emits
Both x-rays and radio waves
The fact that the surface of Mars shows no tectonic activity means that one of the requirements for continuing life might be missing
Carbon-return process
If you are looking down over the south pole of the Earth, you will see the Earth rotate
Clockwise
In our Milky Way Galaxy, the Orion Spur is the
Closest arm to our Sun
Most Kuiper Belt Objects are similar in composition to
Comets
Which of the following types of objects can be reasonably described as "dirty snowballs" or, for the larger ones, "flying icebergs?"
Comets are typically made of ice and frozen gas
Apollo 11 made the first
Crewed landing on the Moon
Which of these Mars rovers has been operating on the surface of Mars for six years so far (as of 2018)?
Curiosity
An advantage of carbon dioxide as the starting form of carbon for use by living things is that it
Dissolves in liquid water
The dark side of the Moon, where the Sun never shines,
Does not exist !!!
Which of these moons has geysers of water shooting out through cracks in the moon, indicating a subsurface ocean?
Enceladus
Although most records from that time were lost in the burning of the Great Library at Alexandria, most historians say that the first actual measurement of the Earth's circumference was made in the 3^{rd} century BCE by
Eratosthenes of Cyrene
Which of these moons has patterns of cracks in the ice on its surface. indicating a subsurface ocean?
Europa
Earth's orbit is currently elliptical enough to make the intensity of sunlight vary by 6 percent. The largest Earth-Sun distance (and lowest intensity sunlight) occurs
Every July
What we refer to as a 'Saturn Ring-plane Crossing' corresponds to what season on Saturn?
Fall or spring equinox
Carbon is essential for all life we know about because it
Forms complex compounds
The largest four moons of Jupiter are referred to as the
Galilean satellites
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 both objects would hit the ground at the same time?
Galileo
Which of the following star-like objects would most likely be considered to be a brown dwarf?
Gliese 229B, luminosity and temperature both below type M9V
A type M star that is known to have three terrestrial-size planets near or in its habitable zone is
Gliese 581
Which of the following types of radiation has the highest frequency on this list?
Green light
The absorption and re-radiation of infrared light by gases such as carbon dioxide is the key process in the
Greenhouse Effect
The possibility that increasing the amount of carbon dioxide in the air will raise the average temperature of the Earth is referred to as the
Greenhouse Effect
According to our current (very tentative) estimates, a spaceship traveling from our Sun to one of the nearest stars such as Alpha Centauri A would probably be traveling through the Oort cloud of our Sun and that of Alpha Centauri A for a distance that is
Half of the whole trip
The Big Bang Theory predicts that most of the dark matter in our galaxy and elsewhere must consist of something other than the known chemical elements. This prediction
Has been tested by looking at rogue planets
Cepheid variable stars with the same luminosity usually
Have similar periods
Gerard Kuiper predicted that the region we now call the "Kuiper Belt" should be empty
He was incorrect because he assumed a mass for Pluto that is now known to be too large
The onset of Helium burning at the core of a star normally begins with
Helium burning at the core
Ultraviolet light is sometimes described as either UV-A or UV-B. The UV-B variety is supposed to be more damaging to your skin. You can conclude that of the two types, the UV-B variety has the
Higher frequency
After the impact of an asteroid large enough to cause global effects, the main worry is smoke and dust
In the stratosphere
One indication that there is a lot of invisible matter in the outer halo of our galaxy is that stars in that region orbit with velocities that
Increase with increasing distance from the center
The dust tail of a comet
Is curved and fuzzy-looking
Observations of the collision of two galaxy clusters have shown that dark matter
Is not the result of an incorrect theory of gravity
A star leaves the horizontal branch in the HR diagram when
It runs out of helium at its core
Which of the following objects has a magnetic field that is tilted relative to its rotation axis but not offset from its center
Jupiter
Which of the following planets has a magnetic field that is thought to be generated by liquid metallic hydrogen?
Jupiter
Which of the following planets or moons has an atmosphere consisting mainly of Hydrogen and Helium?
Jupiter
Which of these planets has a solar day that is shorter than half an Earth day in length?
Jupiter
has a system of rings that consists of dark rocks that are difficult to see
Jupiter
The Far Horizons space probe made close approaches to
Jupiter and Pluto
The statement that the orbit of each planet is an ellipse with the Sun at one focus is due to
Kepler
If we wish to find life with a carbon-return process similar to the one here on Earth, we should look for planets
Larger than Mars
Compared to the rest of the Lunar surface, the Lunar Maria are
Lower and younger
Which of the following statements best describes the presence of water on Mars?
Mars probably had liquid water flowing on its surface at some time in the past
Which planet has no moons
Mercury and Venus
order of planets
Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune
When the fireball of its entry into the atmosphere was spotted from a KLM airliner, asteroid 2008 TC₃ had officially become a
Meteor -Meteor → meteroid → meteorite A meteor is still in space, a meteroid is in the atmosphere, and a meteorite is when it hits the ground
Changes in the intensity of sunlight due to shifts in both the Earth's orbit and rotation axis cause
Milankovich cycles
In comparison to RR Lyra variables, Cepheid variable stars are
More luminous and less common
A star that forms an iron core most likely has a mass of
More than 15 and 20 solar masses
The arms of a spiral galaxy such as ours stand out because they contain
Most of the brightest stars
The Earth's Moon is about 1/4 the size of the Earth. When compared to other planets and their moons, the Earth's Moon is
Much larger than we would expect
The observation that stars farther from the center of our galaxy orbit faster is thought to mean that
Much of the mass is outside the central bulge
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
Much shorter
Within the Local Supercluster, our Local Group of galaxies is
Near the outer edge of the cluster
Which of the following planets does the moon Triton orbit?
Neptune
The first signal received from the 1987 supernova SN1987A came in the form of
Neutrinos
Galileo was the original discoverer of
Newton's First Law of Motion
One of the experiments carried out by the Viking Landers was to use a mass spectrometer to analyze the gas given off from a heated soil sample. The results of that experiment (as interpreted at the time) established that Martian soil contains
No carbon compounds at all
As seen from far above the Earth's South Pole, the Earth orbits the Sun clockwise and
No planets orbit the sun counterclockwise
The moons of Mars are
Not large enough to be spherical -There needs to be a certain amount of pressure in the atmosphere to create large spherical moons
Suppose that a comet is spotted while it is still far from the Sun (beyond the orbit of Mars). The tail of this comet is most likely
Not yet formed
One conclusion that was drawn from the gradual slowing of the radio signals from the Crab Nebula was that they were probably
Of natural origin
Which of these Mars rovers has been operating on the surface of Mars for fourteen years so far (as of 2018)?
Opportunity
The Population II stars of our Milky Way
Orbit the central bulge in all directions
The Doppler shift of familiar spectral lines from gas clouds and stars in our galaxy measures their
Orbital velocities within the galaxy
The star Sirius can be located by using the pointer stars in
Orion
The portion of the Earth that is liquid iron and nickel is the
Outer core
A ring galaxy such as Hoag's Object that is the result of a collision would be classified as a
Peculiar galaxy
The part of a protostar where the density first becomes low enough for light to escape is called the
Photosphere
was an early space probe sent to fly past Jupiter
Pioneer 10
The closest star to the North Celestial Pole that is visible to the naked eye is
Polaris
The phase diagram for water is presented on a graph with axes for temperature and
Pressure The phase change of water depends on the pressure and temperature of water
During a meteor shower, shooting stars seem to be coming from
Radiant
Which of these planets has a rotation axis that is inclined in much the same way as that of Earth?
Saturn
has a hexagon-shaped pattern of clouds near its North Pole
Saturn
A full cycle of day and night on Mars is called a 'sol.' In terms of 24 hour Earth days, a Martian sol is
Slightly longer than one Earth day
Jupiter has the most mass of any planet in our Solar System and is also the largest planet. Objects that have still more mass than Jupiter and are not stars are usually
Smaller than Jupiter
Extragalactic nebulae such as the Great Nebula in Andromeda were not immediately recognized as galaxies similar to our own Milky Way because they were thought to be
Smaller, nearby objects
In the core of a high-mass star, the formation of `degenerate neutron matter' which consists entirely of neutrons that touch one another
Starts a supernova explosion
It is currently thought that moons typically do not form near
Terrestrial planets such as Earth and Mars
Between the orbits of Mars and Jupiter you find
The Asteroid Belt
Icy objects were ejected inward from the neighborhood of the Jovian planets to form
The Earth's oceans and atmosphere
The path of the Sun on the Celestial Sphere is called
The Ecliptic
Which of Kepler's Laws governs how a particular planet speeds up and slows down?
The Equal Area Law
A technological civilization that lasts for astronomically significant periods of time should make an obvious and visible impact on the galaxy and should have figured out how to visit us by now. That leads to the question "So, where are they"? This statement and question is usually referred to as
The Fermi Paradox
Which of Kepler's Laws compares the speeds of different planets?
The Period-Radius Relation
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
The first indication that Cygnus X-1 might be a black hole was
The rapid fluctuations in its x-rays
Copernicus said that the Earth and planets orbiting the Sun caused
The retrograde motion of the planets
One way to change the course of an asteroid is to place a `mass driver' on it. The mass driver is really just a catapult that throws things (like rocks for example) away from the asteroid. The force that acts on the combined object (mass driver plus asteroid) is actually exerted by
The rocks that the catapult throws
Hurricanes and other storms start when the air is unstable. Under which of the following conditions would you expect the air over the ocean to be unstable so that it is likely to give rise to storms?
The temperature of the water is higher than the air above it
Upon close examination by space probes, the rings of Saturn are found to consist of
Thousands of circular rings
In Newton's theory of gravity, everything is attracted
To every other object in the universe
The acceleration of Earth's Moon is
Toward the Earth
A planet that is following Kepler's Laws, accelerates
Toward the sun
The axial tilt of Pluto is most similar to that of
Uranus
Which of the following objects has a magnetic field whose North and South poles are displaced from its rotation axis poles and also from the center of the planet?
Uranus
Which of the following objects has a magnetic field whose origin is not explained by any currently accepted model?
Uranus
Which of the following planets is about 4 times the size of the Earth?
Uranus
An example of a planet with no liquid water at all and a dense carbon dioxide atmosphere is
Venus
At present (within the last few hundred years) the orbit of Mars around the Sun is
Very elliptical so that the intensity of sunlight varies by 40%
The first spacecraft to make detailed maps of the Galilean satellites of Jupiter was/were
Voyager 1 and 2
In the falsifications philosophy of science that we have been discussing, all but one of the following types of statements are possible. Which one is NOT possible?
Well-tested and proven to be true
The star Wemadeit shows a stellar parallax angle of 0.3 seconds of arc while the star Waytoofar shows a stellar parallax angle of 0.2 seconds of arc. From this, you can conclude that
Wemadeit is closer to our Sun than Waytoofar
Cassini-Huygens Spacecraft
Went into orbit around the planet Saturn and dropped a probe into Titan's atmosphere.
A spectral type G star could be a main sequence star like our own Sun or it could be one of several different types of red giant stars. Can we tell which it is just by looking at its spectrum?
Yes. The widths of the spectral lines tell us which it is
One property of a model such as the shape of the Earth is the number of adjustable parameters it has --- the number of numbers that are needed to determine the model. If this number is very large, that is regarded as
a bad thing since it lets the model fit many possible measurements.
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
Hertzsprung-Russell diagram
a graph relating the surface temperatures and absolute brightness of stars From O → M, the stars decrease in temperature* and size (generally) Absolute brightness of stars increase going upward *remember that blue = hot, red = cold
An encounter between Earth and an iron asteroid 50m in diameter would most likely cause
a large explosion on the ground
A rising convection current in the Earth's mantle is expected to cause
a mid-ocean ridge where tectonic plates are spreading apart
The atmospheric pressure on the surface of Mars is
about 1% the surface pressure of Earths atmosphere.
So far (as of 2008), the planet Venus has been visited by
about 20 successful space probes
Besides the object that we call `The Moon,' Earth has
about 500 active artificial satellites and several thousand inactive ones.
When the iron nuclei in the core of an evolved high-mass star start to come apart, they
absorb energy and limit the core temperature
Since 1990, the major spacefaring nations, Europe, China, Russia, Japan, India, and the U.S., have begun to return to the Moon. As of 2009, of these six space programs,
all except Russia have sent probes or orbiters to the Moon
Hydrated minerals on the Moon
are almost completely absent.
Our Sun sends out intense streams of charged particle radiation. Most of these charged particles
are trapped by the Earth's magnetic field for a while and then strike the atmosphere over the poles
In the present surface environment of Mars, water has been confirmed to exist
as short-lived spurts of liquid water.
In Astronomy, the term "Microlensing" refers to the
bending of light from a distant star by the gravity of a nearer object such as a planet
The Tau-Tauri wind from the Sun's final collapse toward ignition
blew away the fuel that Jupiter needed to become a star
As Saturn rotates,
both its magnetic poles remain almost motionless at its geographic poles
When Galileo wanted to understand how falling objects move, he did all of the things on the following list. Choose the one thing that is very different from the way that the ancient greeks approached the subject. He
built inclined planes and measured how balls roll down them
The Ptolemaic model of the Solar System has each planet moving along a
circular epicycle whose center, in turn, moves around the Earth
Stars usually come in clusters, all born at about the same time, because
collapsing interstellar clouds usually fragment
Meteor showers are caused by
comet debris
A sidereal month, is defined to be the time it takes for the Moon to
complete a full circle on the celestial sphere
The currently accepted model of the formation of the Solar System says that the planets
condensed from a disk of matter formed from the rotating Solar Nebula
The strongest evidence that Earth life is all descended from a single self-copying molecule is that all Earth life
contains the same version of molecules that have different mirror-image forms
According to our current (very tentative) estimates, a spaceship travelling from our Sun to one of the nearest stars such as Alpha Centauri A probably
could make the trip in many short hops between rogue planets along the way
Apollo 8 made the first
crewed orbit of the moon
Copernicus said that the rotation of the Earth on its axis caused the
daily motions in the heavens
The intense magnetic field of the Crab pulsar causes its rate of spin to
decrease
Early (before 1970) theoretical estimates of the number of near-Earth asteroids were very low because the astronomers of that time
did not realize that Jupiter's gravity was deflecting asteroids from the Belt
1 astronomical unit =
distance from Earth to the Sun.
A rocket that leaves the Earth's atmosphere at a speed of 8 miles per second will
escape from the Earth's gravity forever
The energy that is released when hydrogen combines with oxygen to form a kilogram of water is always
exactly equal to the energy needed to separate the hydrogen and oxygen in a kilogram of water
Temperatures on the surface of Mercury are
extremely varied because it has no atmosphere to spread the heat
The primary mission of the Kepler Spacecraft is to
find planets in orbit around nearby stars.
The semi-liquid rock that is found inside the Earth
flows like a liquid under gradual pressure but is stiff like a solid under sudden pressure
Suppose that a spacecraft is in a roughly circular orbit near the surface of the Earth, moving at around 5 miles per second. Suppose the spacecraft flips over backwards and fires its rocket engine to slow its speed to 4.96 miles per second. The spacecraft will then
follow an ellipse that descends a bit and then rises again
Supernova explosions tend to
form elements heavier than iron
The Earth's crust is mostly made of
granite
According to our current model of how planets form magnetic fields, the magnetic field of Saturn is much less than the magnetic field of Jupiter because Saturn
has less metallic hydrogen in its core than Jupiter
The rotation rate of Saturn
has not been exactly determined because different methods give somewhat different results
The side of the Moon that faces away from the Earth
has only a few small lunar maria -Lunar maria = the lava that formed from the early beginnings of the moon; there's more on the side of the Earth that faces the moon
Our current understanding of how planets acquire magnetic fields suggests that a planet with a large liquid iron core will
have a magnetic field if it rotates fast enough.
The current model for the way that planets acquire magnetic fields suggests that a rapidly rotating planet will
have a magnetic field if its core contains enough liquid electrical conductor
The second most common element in the universe is
helium
The reason the temperature rises as you go higher in the thermosphere is that the Sun's
high energy particles heat the Ionosphere
The ancient Greeks were able to calculate the distance from the Earth to the Moon by measuring
how long a lunar eclipse lasts
The oceans and atmosphere of Earth are thought to have originated, in part, when
icy objects were ejected inward from among the Jovian planets
The early Earth probably had carbon
in the form of amino acids and other complex hydrocarbons
A model in which the Moon forms by breaking away from the Earth would predict that the Moon's orbit should be
in the plane of the Earth's equator
A model in which the Moon forms from the same rotating cloud of gas and dust as the Earth would predict that the Moon's orbit should be
in the plane of the Earth's equator
Protostars are very bright because of their large surface areas. Most of this energy comes out as
infra-red light with wavelengths too long to see with an ordinary telescope
Seismic waves are used to determine the Earth's
interior structure
Moon's orbit around the earth
is elliptical enough to give us an annular solar eclipse when the Moon is near its apogee.
The Oort Cloud
is the hypothetical (but mostly unobserved) starting point of long-period comets
Mercury rotates so that, relative to the Sun
it rotates just once during two complete orbits around the Sun
One reason that the Copernican System failed to fit Tycho's observations was that
it used circular orbits instead of ellipses
The moon Ganymede is
larger than the planet Mercury but smaller than the planet Mars
The surface of Jupiter is marked by
light and dark bands circulating in opposite directions
The Surveyor series of spacecraft
made unmanned landings on the Moon in the 1960s
The atmospheric pressure at the surface of Venus is
many times the pressure at the surface of the Earth
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 mass that is distributed in different parts of our Milky Way Galaxy is estimated by
measuring how stars orbit the center of the galaxy
Near the center of the Milky Way there is an intense radio source whose mass is approximately three
million solar masses within several light days of the center
The epicenters of earthquakes are located
mostly along the edges of moving plates
Comets that originate in the Inner Oort Cloud would be expected to have orbits that are
mostly close to the plane of the solar system
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
According to the definition of "habitable zone" that we are using, Earth is
near the inner edge of the habitable zone of our Solar System
The observed magnetic field of Mercury is surprising because it was expected to have
no magnetic field at all because it rotates so slowly
Population I stars in our galaxy include
only younger stars such as our sun
On Earth, a stable long-term carbon cycle could not exist without
plate tectonics recycling the sea floor into the Earth' interior
Silicon atoms can bond to other silicon atoms to form polysilylene molecules in much the same way that carbon atoms can bond to other carbon atoms to form sugars and other hydrocarbon molecules. What is the key difficulty with basing life on silicon and polysilylenes instead of on carbon compounds such as glucose?
polysilylenes tend to explode in the presence of oxygen
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 (2018) indicate that
possibilities (2) and (3) actually happen
The magnetic field of Mars is
present only locally, near magnetized ore deposits
Our Sun is a type G2V star on the main sequence. As it ages and uses up its fuel we expect it to
remain a G2V star until it leaves the main sequence
As viewed from the star Polaris, Venus
rotates clockwise and goes around the Sun counter-clockwise
As seen from North America, the constellation Orion
sets in the west and southwest
The microfossils that were found in the martian meteorite ALH84001 are
subject to continued argument because of doubts that they are of biological origin
The Soviet Union had a secret program to put the first human on the Moon. This program
test launched their Moon Rocket several times, but it blew up each time
From his observations of the phases of Venus, Galileo concluded that the Ptolemaic model of planetary motion was wrong because it predicted
that there could never be a Full Venus, but Galileo saw one
Because the radiant of the Lyrid meteor shower is in the constellation Lyra, you can conclude that
the Earth is moving toward Lyra when it passes through the remains of the comet
The capture theory, in which the Moon forms as a separate object similar to Earth and is then captured by the Earth, would predict that
the Moon should have an iron core similar to Earth's
The ancient Greeks were able to estimate the distance from the Earth to the Sun by using
the angle between the Sun and a quarter Moon
For an object that is moving along a straight path, the acceleration is
the change in the object's speed divided by the time it takes - a=m/s2
In comparison to Kepler's Laws of Planetary Motion, Newton's theory of Universal Gravitation predicted almost the same motions, but with small corrections due to
the gravitational attractions between different planets
The temperature on the surface of Venus is
the highest of any planet in the Solar System
A star leaves the main sequence when
the hydrogen in the core is used up
The heat that reaches the surface of Saturn comes mostly from
the interior of Saturn.
Viking 1 and 2 were sent to explore
the planet Mars
In order to use spectroscopic parallax to find the distance to a star, you need to know
the spectral type and luminosity class (B2V for example) and the apparent magnitude
You hear about an asteroid impact threat at level 10 on the Torino Scale. You should
think about ways to get off the planet.
The magnetic field of Jupiter is
tilted relative to the planet's rotation axis but not offset from its center
Pathfinder was the first
to use airbags to land on Mars
Mercury rotates so that its sidereal day lasts for
two thirds of a complete orbit around the Sun.
The reason the temperature rises as you go higher in the stratosphere is that the Sun's
ultraviolet light heats the ozone layer
According to our current model of how magnetic fields arise, the magnetic field of Earth's Moon is
understandable since the Moon rotates slowly and probably has no iron core
A comet that is passing close to the Sun will have a tail that is most likely
very long because sunlight is pushing on it.
A planet whose atmospheric pressure is exactly at the triple point of water and whose surface temperature has a range that includes the triple point will have
water as ice or vapor, depending on the temperature -Extremely high temperatures will lead to vapor/gas because the molecules are going ham but extremely low temperatures will lead to solid/ice because of how cold it is
A world with both liquid water on its surface and carbon dioxide in its atmosphere is unstable because
water dissolves carbon dioxide and takes it out of the atmosphere
The Van Allen Belts are
where Earth's magnetic field traps charged particles from the Sun