Question 1

What are the main characteristics of our solar system?

Accepted Answer

The solar system consists of four terrestrial (small, rocky) planets close to the Sun: Mercury, Venus, Earth, and Mars, and four gas giants (large planets) farther from the Sun: Jupiter, Saturn, Uranus, and Neptune.

Question 2

The overall shape of the orbits of MOST of the planets in the solar system is:

Accepted Answer

The orbits of most planets in the solar system are slightly elliptical, but nearly circular. While some planets (such as Pluto) have highly elliptical orbits, the majority of the planets have orbits that are only slightly elliptical, and therefore appear almost perfectly circular to the naked eye.

Question 3

Most meteoroids are:

Accepted Answer

Most meteoroids are fragments of asteroids. These are small pieces of rocks that break off from asteroids due to collisions or other processes, and they can enter the Earth's atmosphere and create meteors (shooting stars).

Note: While some meteoroids may be ice chipped off comets (A), and others may be interstellar matter (B), these types are less common than meteoroids from asteroids. Option (D) is incorrect because meteoroids are not typically considered debris from the original solar nebula, as those particles would have merged into larger bodies or been blown away long ago.

Question 4

What is the difference between an asteroid and a meteoroid?

Accepted Answer

The main difference between an asteroid and a meteoroid is their size. Asteroids are larger, typically measuring at least a kilometer in diameter, while meteoroids are much smaller, usually measuring only a few meters or less.

Question 5

Comets are typically:

Accepted Answer

Comets are primarily composed of ice, dust, and frozen gas. When they pass close to the Sun, the heat causes the ice to vaporize, creating a glowing coma and a long tail of gas and dust that can be seen from Earth. This process is known as sublimation. Therefore, choice D is the best option as it describes comets being made up of chunks of ice that vaporize when passing close to the Sun.

Question 6

An object in the solar system orbits the Sun and has enough mass that its gravity has pulled it into a spherical shape,but it does not have enough gravity to clear its neighborhood of orbiting debris.This object is classified as a(n):

Accepted Answer

The object described in the question meets the criteria for a dwarf planet, which is defined by the International Astronomical Union as a celestial body that orbits the Sun, is spherical in shape, but has not cleared its orbit of other debris. This definition was established in 2006, and it led to the reclassification of Pluto from a planet to a dwarf planet. Therefore, option D, dwarf planet, is the correct answer.

Question 7

The correct sequence of planets in our solar system from the Sun outward is:

Accepted Answer

The correct sequence of planets in our solar system from the Sun outward is Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. Option B gives this sequence correctly.

Question 8

Each of the following characteristics is included in the formal definition of a planet EXCEPT ONE.Which is the exception?

Accepted Answer

The formal definition of a planet does not include the characteristic of spinning fast enough to produce its own magnetic field. The three characteristics that are included in the definition are: orbits a star directly, has enough mass to pull itself into a roughly spherical shape, and has enough gravity to clear its orbit.

Question 9

A small solar system body CANNOT be a(n):

Accepted Answer

The answer of A small solar system body CANNOT be...

Question 10

A theory of the origin of the solar system must take into account all important general properties of the planets.Which statement does NOT describe an important general property of the planets?

Accepted Answer

The magnetic fields of the planets are produced by a variety of mechanisms is not an important general property of the planets.

Question 11

What is the basic difference between comets and asteroids?

Accepted Answer

The basic difference between comets and asteroids is that comets are mostly composed of ices such as water, carbon dioxide, and methane, whereas asteroids are mainly composed of rocks and metals. Additionally, comets often have a tail when they get closer to the Sun due to the sublimation of their ices, while asteroids do not have a tail. The other options listed in the question are incorrect.

Question 12

The period of Late Heavy Bombardment is believed to have had a number of consequences.Which statement does NOT describe one of these consequences?

Accepted Answer

The Moon's formation is not a consequence of the Late Heavy Bombardment; it is believed to have formed earlier from a collision between Earth and a Mars-sized body.

Question 13

Evidence of extensive cratering can be seen on most bodies in the inner solar system.Two bodies,however,have surfaces that are continually reformed by geologic processes.These bodies are:

Accepted Answer

Venus and Earth have active geology that reshapes their surfaces, such as volcanism and tectonics, which cover up older craters.

Question 14

Which object might be classified as a small solar system body?

Accepted Answer

Small asteroids are classified as small solar system bodies. Small planets and moons of planets are not typically considered small solar system bodies, and while particles in a ring system are technically part of the solar system, they are not typically referred to as small solar system bodies.

Question 15

One consequence of the period of Late Heavy Bombardment is believed to be this: The mantle of a planet was almost obliterated by collisions,leaving it with an unusually large iron core.This planet is:

Accepted Answer

Mercury is believed to have an unusually large iron core relative to its size, which is thought to be a consequence of the Late Heavy Bombardment stripping away much of its mantle.

Question 16

Which object is NOT a dwarf planet?

Accepted Answer

Amalthea is not a dwarf planet, it is a small moon of Jupiter.

Question 17

The MOST noticeably elliptical planetary orbit is the orbit of:

Accepted Answer

Mercury has the most noticeably elliptical orbit among the planets in our solar system, with an eccentricity of about 0.21, making it more elongated compared to the nearly circular orbits of other planets.

Question 18

For the first 400 million years or so after the formation of the solar system,the rate of bombardment by large objects decreased.Then,from about 400 million to 700 million yaers after the formation,this rate increased again.What is believed to be the cause of this increase,the period of Late Heavy Bombardment?

Accepted Answer

The answer of For the first 400 million years or...

Question 19

Viewed from a position above the north pole of the Sun,the direction of the motion of the planets in their orbits is:

Accepted Answer

The motion of planets in their orbits is counterclockwise as viewed from a position above the north pole of the Sun. This direction is also known as prograde motion. There are no exceptions to this for any of the planets, including Venus and Mercury.

Question 20

Pluto was originally classified as a planet,but new criteria for the definition of a planet were adopted,and Pluto failed to meet one of them.Which one?

Accepted Answer

The new criteria for the definition of a planet require it to "clear its orbit." This means that the object must be able to remove any other debris or objects in its orbit through its gravitational pull. Pluto failed to meet this criteria as it shares its orbit with other small objects in the Kuiper Belt. Therefore, Pluto was reclassified as a dwarf planet.

Quiz 4: Formation of the Solar System and Other Planetary Systems