Astronomy Ch. 6 - The Solar System
_______ is the jovian planet that orbits closest to the sun.
jupiter
Conservation of angular momentum means that a spinning body tends to?
keep spinning
Conservation of angular momentum means that a spinning body tends to
keep spinning.
Objects in the Kuiper belt?
lie beyond the orbit of Neptune, and close to the ecliptic
Objects in the Kuiper belt
lie beyond the orbit of Neptune, and close to the ecliptic.
jovian planets?
low average density, a lot of moons, a lot of rings and composed of hydrogen and helium
Which characteristic listed below describes the jovian planets?
low density
The largest asteroid, and probably the only one to be a spherical "world" is
Ceres.
Which of these landed on Venus?
Venera 7
n composition and mass and density, Jupiter is most like:
the Sun
In composition and mass and density, Jupiter is most like:
the Sun.
The smallest sort of interplanetary matter is called
interplanetary dust.
_________ has a rotational axis that is tilted so much it lies nearly in the plane of its orbit.
uranus
________ is the planet with the highest average surface temperature.
venus
Which objects in the solar system have been least modified since the formation of the solar system?
Kuiper Belt objects
Our best close-up views of the jovian moons came from the many passes by:
Galileo.
(SA) What do Pioneer 10 and 11 and Voyager 1 and 2 all have in common?
All four of them flew past Jupiter, and all but Pioneer 10 past Saturn as well. All are now moving so fast from the gravity assists that they are far beyond Pluto, and escaping the Sun's gravity entirely, to become eventually lost in interstellar space.
How do the densities of the jovian and terrestrial planets compare?
All terrestrials are more dense than any of the jovians
How do the densities of the jovian and terrestrial planets compare?
All terrestrials are more dense than any of the jovians.
Which of these spacecraft went into orbit about Saturn in July 2004?
Cassini
Which of the following is considered "interplanetary matter"?
Comet Hale-Bopp
The only spacecraft to be intentionally crashed into Jupiter was:
Galileo.
What was the primary role of dust in the formation of the solar system?
Dust acted as condensation nuclei; platforms to which other particles could attach and form larger particles of matter.
What happens when a solar nebula contracts?
It heats up, It flattens out, It spins faster; all of the above
What happens when a solar nebula contracts?
It heats up, flattens out, spins faster
Which planet by itself contains the majority of mass of all the planets?
Jupiter
Which of the following are the Jovian planets?
Jupiter, Saturn, Uranus, and Neptune only
Which of these is not a characteristic of the solar nebula theory?
Larger planets should form closer to their star, where there is more debris.
The best present maps of the surface of Venus come from the:
Magellan.
Which spacecraft gave us our best information about Mercury, until Messenger arrives in 2009?
Mariner 10
Which statement about Mercury is not correct?
Mariner 10 is now dead, but still in orbit about Mercury.
The Mariner 10 spacecraft visited which bodies in the solar system?
Mercury and Venus
Which statement about the motion of the planets is incorrect?
Most planets move in the Earth's equatorial plane
Which statement about the motion of the planets is incorrect?
Most planets move in the Earth's equatorial plane.
What is the name of the theory that is currently used to describe the formation of the solar system?
Nebular theory
Which of these was the first to cross the asteroid belt and head to Jupiter?
Pioneer 10
Which of these bodies has the lowest density?
Saturn
What is the role of irregularities in the solar system in terms of theories of its origin?
They introduce a need for flexibility in theories of the solar system's origin
What is the role of irregularities in the solar system in terms of theories of its origin?
They introduce a need for flexibility in theories of the solar system's origin.
where would you expect to find terrestrial planets?
Terrestrial planets will likely be located nearer the planetary system's star than any jovian planets.
What is true about solar system densities?
The denser planets lie closer to the Sun
What is true about solar system densities?
The denser planets lie closer to the Sun.
In light of modern solar system theory, why do the orbits of the planets all lie in the same plane?
The early solar nebula flattened into a disk
In light of modern solar system theory, why do the orbits of the planets all lie in the same plane?
The early solar nebula flattened into a disk.
(SA) Explain the stage in which the solar system formed pretty much in a plane.
The flat shape of the solar system is explained by the contraction of a slowly spinning cloud in the solar nebula theory.
(SA) What are the chemical and physical properties of the solar system that any theory of its origin must explain?
The inner planets have high densities, moderate atmospheres, and a mostly rocky composition. The outer planets have low densities, thick atmospheres, and a composition of mostly hydrogen and helium. The asteroids are composed of primitive, unevolved material unlike planets and the comets are icy objects that have also remained unchanged since the formation of the solar system.
What factor caused different planets to form out of different types of material?
The variation in temperature throughout the solar nebula; the higher the temperature, the lower the percentage of light elements in the forming planet.
(SA) For what reasons do we consider the planets of the solar system to be of two fundamentally different types?
There are multiple reasons we consider the planets of the solar system to be of two fundamentally different types. The two types of planets we divide our solar system into are: terrestrial planets and jovian planets. The terrestrial planets have low magnetic fields, small number of moons (if any), and are composed of heavier elements like iron. The jovian planets have very strong magnetic fields, a fairly large number of moons, and are composed of lighter elements like hydrogen and helium. These are the basic reasons as to why we categorize our planets into two different types of planets.
While Cassini was launched toward Saturn in 2004, its Huygens probe in 2005 went to:
Titan.
Which planet is approximately halfway between Pluto's orbit and the Sun?
Uranus, the seventh planet from the Sun
The "Grand Tour" of all four jovians was conducted by:
Voyager 2.
A meteorite is?
a chunk of space debris that has struck the ground
A meteorite is
a chunk of space debris that has struck the ground.
Which of these bodies has the lowest density?
a comet
The jovian planets?
all have rings around their equators
The jovian planets
all have rings around their equators.
A successful theory of the formation of the solar system must explain?
all observed properties of the solar system
A successful theory of the formation of the solar system must explain
all observed properties of the solar system.
Planetary orbits?
are almost circular, with low eccentricities
Planetary orbits
are almost circular, with low eccentricities.
Which of the following is not icy in composition?
asteroids
The tail of a comet always points
away from the Sun and becomes longest and brightest at perihelion.
Most asteroids are found:
between the orbits of Mars and Jupiter
Most asteroids are found:
between the orbits of Mars and Jupiter.
The Kuiper Belt is found where in the solar system?
beyond the orbit of Neptune
A gravitational "sling-shot":
changes the speed and direction of a spacecraft nearing a massive planet.
Which of the following have an icy composition?
comets
What phase of planet formation caused the jovian planets to form?
core-accretion
most of the surface of _________ covered in liquid water.
earth
The plane in which almost all planets orbit the sun is called the:
ecliptic
The plane in which almost all planets orbit the sun is called the:
ecliptic.
Our understanding of the solar system has come in a way that can best be described as:
explosive, with us learning more in the past few decades than in all previous history.
As a rotating gas cloud contracts, it spins
faster due to conservation of angular momentum.
What is the process of accretion?
growth of an object by the accumulation of matter
Dust is an important part of the nebular theory of solar system formation because dust is needed to explain
how the inner planets came to be rocky bodies.
The Kuiper Belt is an "outer asteroid belt" consisting of what types of solar system bodies?
icy cometlike bodies
the only rocky planet to have more then one moon is ________.
mars
the planet that orbits closest to the sun is ________.
mercury
In order to determine the mass of a planet by applying Newton's laws of motion and gravity, the planet must have
moons.
Compared to terrestrial planets, jovian planets are __________.
more massive and lower in average density
_______ is about 30 times as far from the sun as our own planet.
neptune
In composition and density, the asteroids most resemble:
pieces of terrestrial planets
In composition and density, the asteroids most resemble:
pieces of terrestrial planets.
Which of the characteristics below describes the terrestrial planets?
possessing weak magnetic fields
the planet with the lowest average density s _______.
saturn
What aspects of the planets orbits are nearly the same for most planets?
shape and tilt from the ecliptic
The difference between a meteoroid and an asteroid is the object's?
size
The difference between a meteoroid and an asteroid is the object's
size.
terrestrial planets?
small, solid, rocky and located within the inner solar system
The most detailed look we've had of an asteroid comes from
spacecraft sent to an asteroid.
As the solar nebula contracts due to gravitation, the cloud?
spins faster
As the solar nebula contracts it
spins faster due to conservation of angular momentum.
As the solar nebula contracts due to gravitation, the cloud
spins faster.
In composition, asteroids and meteoroids are most like
terrestrial planets.
The meteorites that strike Earth are?
the oldest rocks known
The meteorites that strike Earth are
the oldest rocks known.
Mercury's most unusual orbital feature, as compared to the other planets, is?
the shape of its orbit
Mercury's most unusual orbital feature, as compared to the other planets, is
the shape of its orbit.
What might have made the original solar nebula begin to contract?
the shock wave from a nearby exploding star
The planet's orbital period is:
the time it takes to return to the same location in the sky, relative to the Sun.
The rotation periods of Venus, Jupiter, Saturn, Uranus and Neptune are difficult to determine because?
their surface features are obscured by their atmospheres
The rotation periods of Venus, Jupiter, Saturn, Uranus and Neptune are difficult to determine because
their surface features are obscured by their atmospheres.
Masses of the planets are easiest to determine if:
they have natural satellites whose motions can be precisely measured.
What is the goal of comparative planetology?
to determine the origin and evolution of the solar system
The average density of each planet in the solar system is determined by taking its mass and dividing that by its
volume
The average density of each planet in the solar system is determined by taking its mass and dividing that by its?
volume