Question 1

Why does the dust tail separate from the ion tail?

Accepted Answer

The answer of Why does the dust tail separate from...

Question 2

A comet having an orbit of 50 years would likely have come from the:

Accepted Answer

Comets with orbits of around 50 years are typically short-period comets, which are believed to originate from the Kuiper Belt.

Question 3

Meteorites contain clues to all of the following EXCEPT:

Accepted Answer

Meteorites provide valuable information about the age of the Solar System, the temperature in the early solar nebula, and the composition of the primitive Solar System. However, they do not directly inform us about changes in the rate of cratering in the early Solar System. Cratering rates are typically studied through other means, such as observations of planetary surfaces.

Question 4

In 1994,dozens of fragments of Comet Shoemaker-Levy 9 collided with:

Accepted Answer

Dozens of fragments of Comet Shoemaker-Levy 9 collided with Jupiter in 1994.

Question 5

The most common type of meteorite is:

Accepted Answer

Stony meteorites are the most common type, making up about 94% of all meteorites that have been found on Earth. They are made of mostly silicon, oxygen, and other elements like magnesium, calcium, and aluminum. Iron meteorites make up about 5% of all meteorites and stony-iron meteorites make up less than 1%. Carbonaceous chondrite meteorites are a subtype of stony meteorites.

Question 6

Comet nuclei,absent their tails,are very dark because:

Accepted Answer

Comet nuclei have organic molecules mixed with ice, which makes them very dark.

Question 7

Which of the following is the BRIGHTEST part of a comet?

Accepted Answer

The coma is the brightest part of a comet. This is because the coma is made up of gas and dust that are released from the nucleus as it heats up, and they reflect sunlight, creating a glowing atmosphere around the nucleus. The nucleus and tails (ion tail and dust tail) are typically much fainter in comparison.

Question 8

Which of the following does NOT describe comets in the Oort Cloud?

Accepted Answer

The Oort Cloud is believed to have a spherical distribution of comets, rather than a flattened distribution.

Question 9

The nucleus of the typical comet is approximately ________ in size.

Accepted Answer

The nucleus of a typical comet is approximately 10 km in size, which is much smaller than planets but significant when compared to other small bodies in the solar system.

Question 10

The likely source of comets that mostly have orbits of extreme tilt with respect to the ecliptic is:

Accepted Answer

Comets with extreme tilt orbits are most likely coming from the Oort Cloud, which is a spherical cloud of icy objects located in the outermost region of the solar system. The Oort Cloud is believed to be the source of long-period comets, which have orbits that take them far beyond the orbit of Neptune and can have inclinations of up to 90 degrees with respect to the ecliptic. The Kuiper Belt, on the other hand, is a region of icy objects located mainly beyond the orbit of Neptune, but still within the plane of the ecliptic, and is the source of short-period comets. The asteroid belt and the rings of Saturn are not known to be significant sources of comets.

Question 11

The minimum size of a meteoroid that is capable of surviving its passage through Earth's atmosphere and hitting the ground is about as big as:

Accepted Answer

Meteoroids the size of your fist or larger are generally capable of surviving their passage through Earth's atmosphere to reach the ground as meteorites. Smaller particles tend to burn up due to the intense heat generated by atmospheric friction.

Question 12

The one orbital characteristic both short- and long-period comets share is:

Accepted Answer

Both short-period and long-period comets have highly eccentric orbits, meaning their orbits are elongated and bring them close to the Sun at their perihelion (closest point to the Sun) and far away from the Sun at their aphelion (farthest point from the Sun).

Question 13

The type of meteorites most likely to have originated from the outer layers of differentiated planetesimals come from

Accepted Answer

S-type asteroids are composed of silicate materials and nickel-iron, which are indicative of the outer layers of differentiated bodies.

Question 14

Antarctica is the best hunting ground for meteorites for all of the following reasons EXCEPT:

Accepted Answer

Meteorites do not fall more frequently in Antarctica than in other locations on Earth. The reason Antarctica is a prime location for finding meteorites is due to its ice-covered ground, scarcity of native rocks, and the preservation conditions that protect meteorites from weathering and contamination, not because of an increased rate of meteorite falls.

Question 15

Most comets originate:

Accepted Answer

Comets originate far from the planets, in a region known as the Oort Cloud, which is located many thousands of astronomical units from the Sun. Some comets may also come from the Kuiper Belt, which is a region of icy objects beyond the orbit of Neptune.

Question 16

Suppose we discover a comet whose orbit was very highly eccentric,retrograde,had a very large tilt with respect to the ecliptic plane,and a period of 2,000 years.Where is the most likely place of origin for this comet?

Accepted Answer

The characteristics of this comet -highly eccentric, retrograde, large tilt, and a long period- suggest that it originated from the Oort Cloud. This is because comets from the Kuiper Belt typically have lower eccentricities, shorter periods, and are generally aligned with the ecliptic plane, and the giant planet family is unlikely to produce a comet with a period this long. Comets from outside the Solar System are possible, but less likely than those originating from the Oort Cloud.

Question 17

When a comet comes close to the Sun,its volatile ice sublimates and transforms directly from the solid to ________ phase.

Accepted Answer

When the volatile ice of a comet is heated by the Sun's radiation, it undergoes sublimation, which means it transforms directly from the solid to the gas phase. This gas then forms the characteristic coma and tails of the comet.

Question 18

The radiant of a meteor shower is:

Accepted Answer

The radiant of a meteor shower is the point in the sky from which the meteors in the shower appear to originate, due to the parallel trajectory of the meteoroids that enter Earth's atmosphere. It is not related to the explosion of meteors nor the orbital radius of meteoroids.

Question 19

Cometary nuclei are most likely:

Accepted Answer

Cometary nuclei are porous, meaning they have a low density and are composed of ice, dust, and small rocky particles, but they are not solid ice, purely rocky, or uniform in structure. Their porous nature allows gases to escape when they are heated by the sun, creating a comet's tail.

Question 20

The chronological description of an asteroidal fragment that falls to Earth would be:

Accepted Answer

A meteoroid is a small rocky or metallic body in space, and when it enters the Earth's atmosphere, it becomes a meteor. If the meteor does not disintegrate completely during its entry into the Earth's atmosphere and reaches the ground, it is called a meteorite. Therefore, the correct order would be meteoroid → meteor → meteorite.

Quiz 9: Small Bodies of the Solar System