Asteroids and Comets Answers

Reading Quiz Description: (a) Which best describes the primary difference between asteroids and comets? (b) What is Eris? (c) A typical meteor is created by a particle about the size of a . (d) A rock found on Earth that crashed down from space is called... Part A - Quiz Question 1 Which best describes the primary difference between asteroids and comets? ANSWER: Comets tend to orbit the Sun in the inner solar system, while steroids tend to orbit much farther away. Comets are much larger than asteroids. Comets always have tails and asteroids never have them. Asteroids are rocky and comets are ice-rich. This difference in composition is the primary way that we classify asteroids and comets. Part B - Quiz Question 2 What is Eris? ANSWER: The largest known asteroid An extrasolar planet ejected by another solar system and captured by ours An icy object that orbits in the Kuiper belt and is more massive than Pluto A moon of Pluto It is the most massive known member of the Kuiper belt (as of 2016) and is officially classified as a dwarf planet. Part C - Quiz Question 3 A typical meteor is created by a particle about the size of a _________. ANSWER: baseball pea basketball car We do not see the particle itself, but rather the flash of light it generates as it enters (and burns up in) the atmosphere at high speed. Part D - Quiz Question 4 A rock found on Earth that crashed down from space is called . ANSWER: an impact a meteor a meteorite an asteroid The suffix -ite refers to a rock. Part E - Quiz Question 5 Which statement about asteroids is not true? ANSWER: Most asteroids are not spherical in shape. Many but not all orbit the Sun in the asteroid belt. If we could put all the asteroids together, they would make an object about the size of Earth. Some are more like loosely bound piles of rubble than solid chunks of rock. The total mass of the asteroids is much less than the mass of a terrestrial planet. Part F - Quiz Question 6 The asteroid belt is located . ANSWER: between the orbits of Earth and Mars beyond the orbit of Neptune between the orbits of Jupiter and Saturn between the orbits of Mars and Jupiter It is a "belt" because asteroids have a variety of orbits in this region. Part G - Quiz Question 7 What do we mean by a primitive meteorite? ANSWER: A meteorite that fell to Earth at least 4 billion years ago A type of meteorite that is usually made mostly of high-density metals A meteorite that is essentially unchanged since it first condensed and accreted in the solar nebula almost 4.6 billion years ago A meteorite that was discovered by primitive people It's called primitive because the word means "first." Part H - Quiz Question 8 Among discovered meteorites, we have found some with all the following origins except . ANSWER: being a fragment from the surface of Mars being a fragment of a shattered asteroid being a fragment from the surface of the Moon being a fragment from Comet Halley No such fragments are known and they are unlikely to exist, since comet fragments should be ice that would burn up as they passed through our atmosphere. Part I - Quiz Question 9 Which statement is not thought to be true of all comets in our solar system? ANSWER: Comets always have tails. All comets are leftover planetesimals that originally condensed beyond the frost line in the solar nebula. All comets are icy in composition. All comets orbit the Sun. Only the rare comets that enter the inner solar system have tails and only when they are close to the Sun. Part J - Quiz Question 10 Which direction do a comet's dust and plasma tails point? ANSWER: Perpendicular to the ecliptic plane Always almost due north Generally away from the Sun Straight behind the comet in its orbit They are pushed away from the Sun by radiation and the solar wind. Part K - Quiz Question 11 When a comet passes near the Sun, part of it takes on the appearance of a large, bright ball from which the tail extends. This part is called . ANSWER: the Oort core the nucleus the coma the plasma tail The coma is essentially a large atmosphere of gas and dust released by the comet. Part L - Quiz Question 12 The total number of comets orbiting the Sun is estimated to be about . ANSWER: 1 million 100,000 1,000 1 trillion This number is estimated by counting the number of comets that we see in the inner solar system and then calculating how many must exist in the Oort cloud in order to account for those that we see. Part M - Quiz Question 13 According to current evidence, Pluto is best explained as ______. ANSWER: a terrestrial planet that is surprisingly far from the Sun a large member of the Kuiper belt a very small jovian planet an escaped moon of Jupiter or Saturn It is not even the most massive known member, as Eris is larger in mass (but about the same size). Part N - Quiz Question 14 What is Charon ? ANSWER: the largest known object in the Kuiper belt the largest of Pluto's moons the largest known asteroid a captured moon of Neptune It is much larger than the other moons of Pluto and is thought to have formed in a giant impact with Pluto (much as our own Moon is thought to have formed in a giant impact with Earth). Part O - Quiz Question 15 Which of the following was a new discovery about Pluto by the New Horizons mission? ANSWER: The fact that Pluto is less massive than Eris Evidence of recent geological activity The fact that Pluto has an ice-rich composition The existence of moons orbiting Pluto Few people had suspected that Pluto would be so active given its small size. Part P - Quiz Question 16 What do we mean by a mass extinction ? ANSWER: The extinction of any species of plant or animal that has mass The extinction of large animals, such as dinosaurs An extinction caused by the impact of an asteroid or comet The extinction of a large fraction of the world's plant and animal species in a relatively short period of time Several mass extinctions have been detected in the fossil record, including the one that wiped out the dinosaurs. Part Q - Quiz Question 17 If the hypothesis tracing the extinction of the dinosaurs to an impact is correct, the dinosaurs died off largely because . ANSWER: radiation from iridium in the asteroid caused the dinosaurs to die of cancer of injuries suffered from direct hits of pieces of the asteroid or comet the impact caused massive earthquakes worldwide of global climate effects initiated by dust and smoke that entered the atmosphere after the impact Review your text for the details of how this is thought to have occurred. Part R - Quiz Question 18 Objects the size of the one that exploded over Chelyabinsk (Russia), causing significant damage, probably hit Earth at least . 7 of 7 ANSWER: once every 500,000 years once a century once every 100 million years once a year This is one reason why many people advocate a more careful search for potential impact threats. ! All Assignments 3/8/22, 12:16 PM