Question 1

Pluto is the most massive member of the Kuiper Belt.

Accepted Answer

Pluto is no longer classified as a planet and is instead categorized as a "dwarf planet". It is a member of the Kuiper Belt, but it is not the most massive. That title now belongs to Eris.

Question 2

Although asteroids are small individually, when combined they make up about a quarter of all the mass in the Solar System, excluding the Sun.

Accepted Answer

Asteroids only account for a small fraction of the mass in the Solar System, estimated to be less than 0.1%. The majority of the mass is in the Sun, with the gas giants (Jupiter, Saturn, Uranus, and Neptune) also contributing significantly.

Question 3

Pluto is classified as a dwarf planet because:

Accepted Answer

Pluto is classified as a dwarf planet because it has not cleared out other bodies from its orbit. This means that it shares its orbital space with other objects beyond Pluto, unlike the eight planets in the solar system which have cleared their orbits of other bodies.

Question 4

All short-period comets have periods less than or equal to 20 years.

Accepted Answer

Short-period comets are generally defined as having orbital periods of less than 200 years, not 20 years.

Question 5

Like meteoroids and asteroids, cometary nuclei in the Oort Cloud undergo frequent collisions that often send them into the inner Solar System.

Accepted Answer

The Oort Cloud is a distant region of the Solar System where cometary nuclei are sparsely distributed, making collisions infrequent.

Question 6

Eris is classified as an asteroid even though its mass is 28 percent larger than Pluto's mass.

Accepted Answer

Eris is not classified as an asteroid, but as a dwarf planet along with Pluto. Both are considered part of the Kuiper Belt, a region beyond Neptune that is home to many icy bodies.

Question 7

Some asteroids have moons just like planets do.

Accepted Answer

This is true. There are several asteroids in our solar system that have moons, including the asteroid Ida, which has a small moon named Dactyl.

Question 8

Pluto has a density that is roughly equal to two times that of:

Accepted Answer

Pluto's density is about 1.86 g/cm³, which is roughly twice that of water (1 g/cm³).

Question 9

The dwarf planet Eris has a moon called Dysomia, which is much smaller in mass than Eris. If Dysomia has an orbital period of 16 days and orbits Eris at a distance of 40,000 km, then what is the mass of Eris?

Accepted Answer

Using Kepler's third law and the formula for gravitational force, the mass of Eris can be calculated as approximately 2.27 x 10^22 kg, which is closest to option B.

Question 10

Eris, Ceres, and Haumea are examples of:

Accepted Answer

Eris, Ceres, and Haumea are all dwarf planets, which are celestial bodies in our solar system that are not large enough to be considered full planets but are larger than asteroids.

Question 11

Pluto is composed primarily of rock.

Accepted Answer

Pluto is primarily composed of ice and rock, with ice being a significant component.

Question 12

Most asteroids are found in orbit around the Sun between the orbits of Jupiter and Saturn.

Accepted Answer

Most asteroids are found in the asteroid belt, which is located between the orbits of Mars and Jupiter, not between Jupiter and Saturn.

Question 13

The mass of Pluto is approximately 100 times less than that of Earth.

Accepted Answer

The mass of Pluto is actually about 500 times less than that of Earth.

Question 14

Astronomers can use the speed and direction of a cometary meteor's flight to identify its parent comet.

Accepted Answer

This is true. Cometary meteors are debris left behind by comets as they orbit the sun. By studying the trajectory of a meteor, astronomers can backtrack to its origin point and identify the comet that it came from.

Question 15

Which of the following types of Solar System debris were NOT discovered until the age of telescopes?

Accepted Answer

Asteroids were not discovered until the age of telescopes, with the first one, Ceres, being discovered in 1801.

Question 16

All meteorites are remnants of planetesimals that never coalesced to form a planet.

Accepted Answer

Not all meteorites are remnants of planetesimals; some originate from larger bodies like asteroids or even planets that have undergone collisions or other processes.

Question 17

Which of following is FALSE?

Accepted Answer

Pluto's mass is actually only 0.002 times that of Earth's mass, making it much smaller.

Question 18

Cometary nuclei provide evidence that the ingredients necessary for the creation of life were present in the early solar nebula.

Accepted Answer

Cometary nuclei contain organic compounds such as amino acids, which are essential building blocks for life. This suggests that these compounds were present in the early solar nebula, from which the planets and comets formed.

Question 19

Meteorites are more likely to come from asteroids than comets.

Accepted Answer

Meteorites are primarily made up of rocky or metallic material, which is more commonly found in asteroids rather than comets. Comets are typically made up of ice and dust, which vaporize upon entering Earth's atmosphere and do not leave behind a solid meteorite.

Question 20

The most common type of meteorites found are iron meteorites.

Accepted Answer

The most common type of meteorites found are actually stony meteorites, which are made up of silicate minerals.

Quiz 12: Dwarf Planets and Small Solar System Bodies