Download The most important questions to study for the exam

Comins DEU 3e Ch 06 Quiz 2 completed
The correct answers are written in bold, italic and underlined.
The most important questions to study for the exam are highlighted.
1. Comets typically have two tails, one straight and the other curved.
Which is which?
• The straight tail consists of gas and dust from the comet, and the curved tail consists of solar wind ions
deflected by the comet's nucleus.
• The straight tail consists of dust, and the curved tail consists of gas.
• The straight tail consists of gas, and the curved tail consists of dust.
2. Three ways in which we might think a comet could be destroyed are:
slow evaporation by solar radiation; rapid destruction if a comet passes
too close to the Sun; direct collision with a planet. How many of these
have we actually seen in action?
• All three
• Just one: slow evaporation, producing the comet's tail
• Two: slow evaporation (which produces the comet's tail) and destruction by passing too close to the Sun
3. How has the existence of comets around another star besides the Sun
been established?
• The spectrum of ice has been observed at distances of several hundred AU from the star.
• The spectrum of water vapor has been observed as the star vaporizes some of its comets.
• Streams of ions have been observed extending for several AU outwardsfrom the star.
4. A meteor is
• a small, rocky or metallic object in orbit around the Sun.
• a flash of light as an object from space hurtles through our atmosphere.
• an object from space that has landed on the surface of the Earth.
5. Which name describes a bright meteor that explodes as it travels
through the Earth's atmosphere?
• A fireball
• A bolide
• A meteorite
6. If the majority of the craters on the Moon were caused by impacts
from asteroids and meteoroids from space, why then are there so few
equivalent craters from such impacts on the Earth?
• Because geological processes and erosion by water and wind have destroyed most of the craters that have
formed on the Earth
•
•
Because the Moon was bombarded by material in a very different region of the solar system before it was
captured by the Earth's gravity
Because the gravitational field of the Moon attracted incoming objects and this shielded the Earth from these
impacts
7. Which of the following statements most accurately describes the
situation of matter from space hitting the Earth and its atmosphere?
• Space matter hits the Earth only at certain times each year in so-called meteor showers, with a wide range of
particle sizes, some of which reaches the Earth's surface.
• Matter is falling continuously onto the Earth and its atmosphere all the time, with a wide range of particle
sizes.
• Matter in space exists only in relatively large sizes, and these impact the Earth only very infrequently
(fortunately!) to produce craters and to lead to catastrophic extinction of many life-forms.
8. The solar system is believed to be 4.57 billion years old. How is
this number known so accurately?
• From the measured ages of the oldest meteorites
• From the measured ages of "pristine" comets, i.e., those that are falling into the inner solar system for the first
time
• From the observed cratering ages of asteroids, such as Gaspra and Eros, that have been visited by spacecraft
9. Most of the meteoric material falling onto the Earth from space is
composed of
• ices (such as water, ammonia, and methane).
• stony material.
• iron and nickel.
10. What does the presence of Widmanst‰tten patterns in iron meteorites
tell us?
• The meteorite was subjected to sudden and extreme stress when the larger object of which it was a part was
struck and shattered by collision with another object.
• The material of which the meteorite is composed contains significant quantities of water.
• The meteorite cooled slowly as part of a larger asteroid.
11. An important class of meteorites made of early solar system material
that has not been significantly altered since it first formed is the
• iron-nickel meteorite.
• carbonaceous chondrite.
• stony-iron meteorite.
12. What evidence has been found inside some meteorites that leads to
the conclusion that a supernova explosion occurred near the solar system
about 4.6 billion years ago?
• Observation of a burnt fusion crust all over the surface of some meteorites that can only have been produced by
an intense explosion
•
•
Discovery of by-products of radioactive decay of a short-lived isotope of aluminum that could only have been
produced by a supernova explosion
Detection of certain long-chain molecules, amino acids. The required chemical reactions to produce these long
chains can only have been triggered by the intense radiation burst produced in a supernova explosion.
13. There are two pieces of evidence in the geological record of rocks
throughout the world at an age of 65 million years that suggest a
cause-and-effect relationship. These are
• a large crater in the desert in Arizona, USA, and a layer of clay across the North American continent containing
abnormal amounts of a rare metal, iridium, that is relatively abundant in some meteorites.
• the sudden extinction of two-thirds of all life-forms (including the dinosaurs) and a layer of clay containing
abnormal amounts of a rare metal, iridium, that is relatively abundant in some meteorites.
• the evolution at this time of mammalian species whose blood contained large amounts of iron and the presence
at this geological level of a rich layer of iron, of which many meteorites are made.