Astronomy 101 Module 12 Chapter 12

Which of the following statements best describes the size of the largest asteroid, Ceres? Its diameter is a little larger than a quarter the diameter of our Moon. It is smaller than the jovian planets but larger than the terrestrial planets. It is about the size of a terrestrial planet. It is no larger than a typical mountain on one of the terrestrial planets.

If we could put all the asteroids together, their total mass would be ______. about the mass of Mercury greater than the mass of Earth but less than the mass of Jupiter much less than the mass of any terrestrial planet about the mass of Earth

Why didn't a planet form where the asteroid belt is now located? There was not enough material in this part of the solar nebula to form a planet. The temperature in this portion of the solar nebula was just right to prevent rock from sticking together. There was too much rocky material to form a terrestrial planet, but not enough gaseous material to form a jovian planet. Gravitational tugs from Jupiter prevented material from collecting together to form a planet.

Gaps in the asteroid belt (often called Kirkwood gaps) are caused by ______. orbital resonances with Jupiter the competing gravitational tugs of Mars and Jupiter tidal forces from the Sun tidal forces from Jupiter

When you see the bright flash of a meteor, what are you actually seeing? a star that has suddenly shot across the sky the flash that occurs when a speeding rock from space hits the ground the glow from a pea-size particle and the surrounding air as the particle burns up in our atmosphere emission of visible light from a particle that has not yet entered Earth's atmosphere

How can we determine the reflectivity of an asteroid? By where it is located in the asteroid belt. By measuring its mass and radius. By taking a photograph of it. By comparing its brightness in visible light to its brightness in infrared light.

In science fiction movies, spaceships are often shown dodging through large numbers of closely spaced, boulder-size objects. Which of the following real things in our solar system would look most like such science fiction dangers? the asteroid belt the atmosphere of Jupiter the rings of Saturn the Oort cloud

Suppose you find a meteorite made almost entirely of metal. According to current science, which of the following statements must be true? Your meteorite is a fragment of an object from the Kuiper belt. Your meteorite was blasted off the surface of Mars by an impact. Radiometric dating will show the age of your meteorite to date to the formation of our solar system. Your meteorite is a fragment from the core of a large asteroid that shattered in a collision.

Which of the following objects are probably not located in the same region of the solar system in which they originally formed? Kuiper belt comets Oort cloud comets asteroids of the asteroid belt Pluto

Suppose there were no solar wind. How would the appearance of a comet in our inner solar system be different? It would be much brighter in appearance. It would have only one tail instead of two. It would not have a coma. It would not have a nucleus.

Suppose we discover a new comet on an orbit that brings it closer to the Sun than Mercury every 125 years. What can we conclude? It has been on its current orbit for only a very short time compared to the age of our solar system. It has a coma and tail during most of each orbit. It came from the Kuiper belt. It came from the Oort cloud.

When we see a meteor shower, it means that _________. you should duck and run for cover to avoid being blasted on the head by a rock from space Earth is crossing the orbit of a comet an Earth-approaching asteroid has recently come very close to our planet the solar wind is unusually strong

Why won't Pluto collide with Neptune? Pluto orbits the Sun exactly 2 times for every 3 Neptune orbits, which ensures they never come close together. Pluto's orbit never comes anywhere close to Neptune's orbit. Actually, a collision of the two is inevitable within the next billion years. Pluto is always much farther from the Sun than Neptune.

What is Pluto's moon Charon thought to have in common with our own Moon? It has the same approximate mass. It has the same average density. It probably formed as a result of a giant impact. It has the same basic composition.

Which of the following is not a piece of evidence supporting the idea that Pluto is a large comet of the Kuiper belt? Pluto's orbit is very similar to the orbits of other known Kuiper belt comets. Triton, which must once have orbited the Sun before being captured by Neptune, is significantly larger than Pluto. Pluto grows a coma and a long tail when it is at the point in its orbit closest to the Sun. Pluto is not the largest object orbiting in the region of the Kuiper belt. Pluto's composition appears to match that of other known Kuiper belt comets.

The discovery of Eris __________. was not surprising, because the existence of a massive "Planet X" had been predicted nearly a century ago was not surprising, because other Kuiper belt objects approaching the size of Pluto had already been discovered was surprising, since we thought we knew about all large objects in the solar system was surprising, due to its "backwards" orbit around the Sun

Which of the following is not a piece of evidence supporting the idea that an impact caused the mass extinction that occurred 65 million years ago? Fossilized dinosaur bones contain fragments of rock from the impact. A large impact crater along the coast of Mexico dates to 65 million years ago. Grains of quartz formed under high pressure are found in a layer of clay that dates to 65 million years ago. Unusually large abundances of iridium and other rare metals are found in a layer of clay that dates to 65 million years ago.

Suppose that large jovian planets had never formed in our solar system. Which of the following would most likely be true? Earth would have suffered far fewer impacts. Earth would orbit much closer to the Sun. Neither the asteroid belt nor Oort cloud would exist. There would be a large empty region in our solar system between the orbit of Mars and the Kuiper belt.