Asteroids, Comets, and Meteorites: Cosmic Invaders of the Earth (The Living Earth)
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Asteroids, comets, and meteorites have been objects of fascination, speculation, and fear for most of recorded human history. Impacts of comets and meteorites with Earth are now recognized as the main cause for several periods of mass extinction on the planet, including termination of the dinosaurs 66 million years ago...In this book Jon Erickson brilliantly presents the reader with a fascinating and readable treatise on asteroids, comets, and meteorites., From the Foreword by Timothy Kusky
Between 4.2 and 3.9 billion years ago. A swarm of debris left over from the creation of the solar system bombarded Earth. The bombardment might have delivered heat and organic compounds to the planet, sparking the rapid formation of primitive life. Alternatively, the pummeling could have wiped out existing life-forms in a colossal mass extinction. The Formation of Earth The bombardment eventually tapered off to a somewhat steady rain of asteroids and comets. When Earth acquired a permanent.
Ago, perhaps the greatest extinction Earth has ever known eliminated more than 95 percent of all species, mostly marine invertebrates.Trilobites (Fig. 45), a famous group of marine crustaceans and a favorite among fossil collectors, suffered final extinction at this time. On land, more than 80 percent of the reptilian families and 75 percent of the amphibian families (Fig. 46) also disappeared. The extinctions began gradually, with a more rapid pulse at the end. Only a catastrophic event such as.
Annually. Most meteorites are lost because they disintegrate in the atmosphere or plunge into the ocean.Yet meteorites that do land on the ground appear to do so most likely in the afternoon. Asteroids also occupying certain zones, known as resonances, within the outer part of the main belt are greatly influenced by Jupiter’s gravity due to its close proximity.The giant planet’s pull can dramatically elongate the orbits of these asteroids, causing their paths to cross the orbits of the inner.
Venus, Galileo began taking pictures of the cloud-shrouded planet. Figure 87 A view of asteroid Ida with moon Dactyl and of asteroid Gaspra (insert), from Galileo. (Photo courtesy NASA) 115 Asteroids, Comets, and Meteorites Figure 88 The flight path of Galileo to Jupiter, with flybys of Venus, Earth, and the asteroid belt. Flyby (2) Dec 1992 Flyby (1) Dec 1990 Launch Oct/Nov 1989 Earth Venus Flyby Feb 1990 Asteroid belt Probe release Arrival Dec 7, 1995 Jupiter On October 29, 1991,.
Meteorites Figure 5 The Milky Way galaxy. (Photo courtesy NOAO) 8 few hundred million light years of Earth. It forms a sheet some 300 million light-years long. The galaxies combined into clusters, which accumulated into superclusters that wandered through space in seemingly haphazard motions. Superclusters are filamentary in shape and extend up to hundreds of millions of light-years across.This makes them some of the largest structures. Most massive stars either collapsed into black holes or.