NATS1740 Assignment 14

Which is closest to the average distance between asteroids in the asteroid belt? 1. 1 million km 2. 100 thousand km 3. 10 thousand km 4. 1 thousand km 5. 10 million km

1. 1 million km

Which of the following statements about comets and asteroids is true? 1. Comets are balls of ice and dust. 2. Most of the trillions of comets in our solar system have tails. 3. Only asteroids collide with Earth. 4. There are about 1 million known asteroids in the solar system. 5. All asteroids lie in the asteroid belt between Mars and Jupiter.

1. Comets are balls of ice and dust.

What is Charon? 1. Pluto's moon 2. one of the Galilean moons of Jupiter 3. the largest known comet 4. the largest known asteroid 5. a moon of Neptune

1. Pluto's moon

How big an object causes a typical shooting star? 1. a grain of sand or a small pebble 2. a boulder 3. an object the size of a car

1. a grain of sand or a small pebble

Halley's comet is named after the English scientist Edmund Halley because he 1. calculated its orbit and predicted that it would return in 1758. 2. was the first to see it in 1682. 3. was the most famous astronomer in England during its appearance. 4. discovered it. 5. was the first to publish pictures of it and report it to the International Astronomical Union (IAU).

1. calculated its orbit and predicted that it would return in 1758.

When do comets generally begin to form a tail? 1. inside of Jupiter's orbit 2. between Mercury and Earth's orbit 3. inside Mercury's orbit 4. beyond Jupiter's orbit 5. They always have a tail (until they run out of material).

1. inside of Jupiter's orbit

A comet's plasma tail always points directly away from the Sun because __________. 1. of pressure exerted by the fast-moving charged particles in the solar wind 2. centrifugal forces throw the tail outward as the comet travels around the Sun 3. the comet's nucleus overheats on the Sun-facing side, forcing energetic jets of gas to shoot out from the dark side 4. the tail is left behind as the comet moves through its orbit

1. of pressure exerted by the fast-moving charged particles in the solar wind

How does the largest asteroid, Ceres, compare in size to other solar system worlds? 1. It is smaller than any jovian moon. 2. It is about half the size of Pluto. 3. It is about the size of Pluto. 4. It is about the size of a large jovian moon. 5. It is larger than Pluto and Mercury.

2. It is about half the size of Pluto.

Which are thought to have formed farthest from the Sun? 1. asteroids 2. Kuiper belt comets 3. Oort cloud comets

2. Kuiper belt comets

The asteroid belt lies between the orbits of 1. Earth and Mars. 2. Mars and Jupiter. 3. Jupiter and Saturn.

2. Mars and Jupiter.

Did a large terrestrial planet ever form in the region of the asteroid belt? 1. No, because there was never enough mass there. 2. No, because Jupiter prevented one from accreting. 3. Yes, but it was shattered by a giant impact.

2. No, because Jupiter prevented one from accreting.

Why does the plasma tail of a comet always point away from the Sun? 1. Radiation pressure from the Sun's light pushes the ions away. 2. The solar wind electromagnetically "blows" the ions directly away from the Sun. 3. The conservation of the angular momentum of the tail keeps it always pointing away from the Sun. 4. It is allergic to sunlight. 5. Gases from the comet, heated by the Sun, push the tail away from the Sun.

2. The solar wind electromagnetically "blows" the ions directly away from the Sun.

A comet entering the inner solar system from afar will __________. 1. form a tail and some time later form a coma. 2. form a coma and some time later form a tail 3. always form a tail, but only sometimes form a coma

2. form a coma and some time later form a tail

Where did comets that are now in the Kuiper belt originally form? 1. inside Jupiter's orbit 2. near the radius at which they orbit today 3. in the Oort cloud 4. in the asteroid belt 5. between the orbits of Jupiter and Neptune

2. near the radius at which they orbit today

The large gaps in the asteroid belt (often called Kirkwood gaps) are caused by 1. tidal forces from the Sun. 2. orbital resonances with Jupiter. 3. large asteroids that clear certain regions of the asteroid belt. 4. the competing gravitational tugs of Mars and Jupiter. 5. tidal forces from Jupiter.

2. orbital resonances with Jupiter.

What is the size of the largest asteroid? 1. 10,000 km 2. 100 km 3. 1,000 km 4. 1 km 5. 10 km

3. 1,000 km

Which have the most elliptical and tilted orbits? 1. asteroids 2. Kuiper belt comets 3. Oort cloud comets

3. Oort cloud comets

Why won't Pluto collide with Neptune? 1. Pluto's orbit is completely outside Neptune's orbit. 2. Pluto's orbit is completely inside Neptune's orbit. 3. The two planets have an orbital resonance that prevents them from colliding. 4. Pluto's orbit never comes anywhere close to Neptune's orbit. 5. It could!

3. The two planets have an orbital resonance that prevents them from colliding.

Can an asteroid be pure metal? 1. No, all asteroids contain rock. 2. Yes, it must have formed where only metal could condense in the solar nebula. 3. Yes, it must have been the core of a shattered asteroid.

3. Yes, it must have been the core of a shattered asteroid.

What does Pluto most resemble? 1. a terrestrial planet 2. a jovian planet 3. a comet

3. a comet

The combined mass of all the asteroids in the asteroid belt is 1. about the same as that of Jupiter. 2. about the same as that of Earth. 3. less than that of any terrestrial planet. 4. more than that of all the planets combined. 5. about twice that of Earth.

3. less than that of any terrestrial planet.

Where did comets that are now in the Oort cloud originally form? 1. within the solar nebula, but far outside the orbit of Pluto 2. inside Jupiter's orbit 3. near the jovian planets 4. outside Neptune's orbit 5. all of the above

3. near the jovian planets

A typical shooting star in a meteor shower is caused by a ________ entering Earth's atmosphere. 1. pea-size particle from an asteroid 2. boulder-size particle from a comet 3. pea-size particle from a comet 4. microscopic particle of interstellar dust 5. boulder-size particle from an asteroid

3. pea-size particle from a comet

During the time that a comet passes through the inner solar system, the comet can appear quite bright because __________. 1. heat from the Sun causes the comet's nucleus to glow 2. increasing friction causes the comet's nucleus to glow 3. sunlight reflects off the comet's tail and coma 4. sunlight reflects off the comet's nucleus

3. sunlight reflects off the comet's tail and coma

What is the typical size of comets that enter the inner solar system? 1. 1000 km 2. 1 km 3. 100 km 4. 10 km 5. Comet sizes are unknown because their tails obscure the nucleus.

4. 10 km

Why do asteroids and comets differ in composition? 1. Comets are much larger than asteroids. 2. Asteroids are much larger than comets. 3. Comets formed from the jovian nebula, while asteroids did not. 4. Asteroids formed inside the frost line, while comets formed outside. 5. Asteroids and comets formed at different times.

4. Asteroids formed inside the frost line, while comets formed outside.

Why isn't there a planet where the asteroid belt is located? 1. There was too much rocky material to form a terrestrial planet, but not enough gaseous material to form a jovian planet. 2. A planet once formed here, but it was broken apart by a catastrophic collision. 3. There was not enough material in this part of the solar nebula to form a planet. 4. Gravitational tugs from Jupiter prevented material from collecting together to form a planet. 5. The temperature in this portion of the solar nebula was just right to prevent rock from sticking together.

4. Gravitational tugs from Jupiter prevented material from collecting together to form a planet.

Why aren't small asteroids spherical in shape? 1. Small asteroids have odd shapes because they were all chipped off larger objects. 2. Large asteroids became spherical because many small collisions chipped off pieces until only a sphere was left; this did not occur with small asteroids. 3. Large asteroids were once molten and therefore became spherical, but small asteroids were never molten. 4. The strength of gravity on small asteroids is less than the strength of the rock.

4. The strength of gravity on small asteroids is less than the strength of the rock.

An icy leftover planetesimal orbiting the Sun is 1. an asteroid. 2. a meteorite. 3. a meteor. 4. a comet. 5. possibly any of the above

4. a comet.

What is a meteorite? 1. a comet that burns up in Earth's atmosphere 2. a streak of light caused by a small particle from space burning up in Earth's atmosphere 3. a small moon that orbits one of the giant planets 4. a fragment of an asteroid from the solar system that has fallen to Earth's surface 5. a streak of light caused by a star moving across the sky

4. a fragment of an asteroid from the solar system that has fallen to Earth's surface

A rocky leftover planetesimal orbiting the Sun is 1. a comet. 2. a meteor. 3. a meteorite. 4. an asteroid. 5. possibly any of the above

4. an asteroid.

Comets with extremely elliptical orbits, like comets Hyakutake and Hale-Bopp, 1. come from the asteroid belt. 2. come from the Kuiper belt. 3. are captured by Jupiter. 4. come from the Oort cloud. 5. are Trojan comets.

4. come from the Oort cloud.

What characteristic distinguishes a meteorite from a terrestrial rock? 1. Meteorites contain rare elements, such as iridium, that terrestrial rocks do not. 2. Meteorites have different isotope ratios of particular elements when compared to terrestrial rocks. 3. A meteorite usually has a high metal content. 4. A meteorite is usually covered with a dark crust from burning in Earth's atmosphere. 5. All of the above are true.

5. All of the above are true.

What do asteroids and comets have in common? 1. They have similar orbital radii. 2. They have similar densities. 3. They have a similar range of orbital inclinations. 4. They have nothing in common with each other. 5. Most are unchanged since their formation in the solar nebula.

5. Most are unchanged since their formation in the solar nebula.

When was Pluto discovered? 1. about 30 years ago 2. about 200 years ago 3. in ancient history 4. about 2000 years ago 5. about 80 years ago

5. about 80 years ago

Meteorites can come from 1. the Moon. 2. Mars. 3. comets. 4. the cores of asteroids. 5. all of the above

5. all of the above

Where are the Trojan asteroids located? 1. on orbits that cross Mars's orbit 2. in the center of the asteroid belt 3. on orbits that cross Earth's orbit 4. surrounding Jupiter 5. along Jupiter's orbit, 60∘ ahead of and behind Jupiter

5. along Jupiter's orbit, 60∘ ahead of and behind Jupiter

Listed following are some distinguishing characteristics of comets, meteors, and asteroids. Match these to the appropriate category of objects. - most are located either in kuiper belt or oort cloud -dust particles entering earth's atmosphere at high speed - typically orbit the sun at approximately 3 au - form a coma when near the Sun - visible in the sky as a bright streak of light for only a few seconds - compositions similar to that of the terrestrial planets - visible in the sky as a fuzzy patch of light that rises and sets with the stars

Comets - form a coma when near the Sun - most are located either in kuiper belt or oort cloud - visible in the sky as a fuzzy patch of light that rises and sets with the stars Meteors - visible in the sky as a bright streak of light for only a few seconds -dust particles entering earth's atmosphere at high speed Asteroids - compositions similar to that of the terrestrial planets - typically orbit the sun at approximately 3 au

Listed following are several objects in the solar system. Rank these objects from left to right based on their distance from the Sun, from closest to farthest. a trojan asteroid b typical kuiper belt object c typical oort cloud object d typical asteroid in the asteroid belt

a typical asteroid in the asteroid belt, a trojan asteroid, a typical kuiper belt object, a typical oort cloud object

Listed following are several objects in the solar system. Rank these objects from left to right based on their orbital period around the Sun from shortest to longest. a trojan asteroid b typical kuiper belt object c typical oort cloud object d typical asteroid in the asteroid belt

a typical asteroid in the asteroid belt, a trojan asteroid, a typical kuiper belt object, a typical oort cloud object

Listed following are several objects in the solar system. Rank these objects from left to right based on the distance from the Sun at which they are presumed to have formed, from nearest to farthest. 1. a typical kuiper belt object 2. a typical asteroid in the asteroid belt 3. a typical orrt cloud object

a typical asteroid in the asteroid belt, a typical oort cloud object, a typical kuiper belt object