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