Impacts On Earth

The essential guide to 139 sites where the Earth has had a direct hit from space.

Leading specialists in various disciplines were first invited to a multidisciplinary workshop funded by ICSU on the topic to gain a better appreciation and perspective on the subject of comet/asteroid impacts as viewed by different disciplines. This volume provides a necessary link between various disciplines and comet/asteroid impacts.

At a level accessible to the general reader, this balanced and non-polemical book describes the changes human activities have produced in the global environment from 300 years ago to today.

As end-of-the-world scenarios go, an apocalyptic collision with an asteroid or comet is the new kid on the block, gaining respectability only in the last decade of the 20th century with the realisation that the dinosaurs had been wiped out by just such an impact. Now the science community is making up for lost time, with worldwide efforts to track the thousands of potentially hazardous near-Earth objects, and plans for high-tech hardware that could deflect an incoming object from a collision course – a procedure depicted, with little regard for scientific accuracy, in several Hollywood movies. Astrophysicist and science writer Andrew May disentangles fact from fiction in this fast-moving and entertaining account, covering the nature and history of comets and asteroids, the reason why some orbits are more hazardous than others, the devastating local and global effects that an impact event would produce, and – more optimistically – the way future space missions could avert a catastrophe.

Impact phenomena play an essential role in the formation of planets and great influence during their evolution. The first part of this book describes the dynamics that propels asteroids in our solar system; the second part is devoted to impact phenomena; the third inspects terrestrial impacts of asteroids and the hazards due to space debris orbiting our planet. The book addresses scientists working in astronomy, extraterrestrial physics and geophysics. But it should also be of great interest to a learned public that wants to know about the most recent developments in this fast-moving field of theoretical and observational research.

This book tells the story of the catastrophic impact of the giant 10 Km asteroid Chicxulub into the ancient Gulf of Mexico 65.5 million years ago. The book begins with a discussion of the nature of asteroids and the likelihood of future Earth-impacts. The story then turns to the discovery of a global sediment layer attributed to the fallout from the impact and a piecing together of the evidence that revealed a monster crater, buried under the Gulf. Reviewed is the myriad of geological and fossil evidence that suggested the disastrous sequence of events occurring when a "nuclear-like" explosion ripped through the sea, Earth, and atmosphere, thus forming the mega-crater and tsunami. The aftermath of the Chicxulub's event initiated decades and more of major global climate changes including a "Nuclear Winter" of freezing darkness and blistering greenhouse warming. A chapter is dedicated to the science of tsunamis and their model generation, including a portrayal of the globally rampaging Chicxulub waves. The asteroid's global devastation killed off some 70% of animal and plant life including the dinosaurs. The study of an ancient Cambrian fossil bed suggests how "roll of the dice" events can affect the future evolution of life on Earth. We see how Chicxulub's apparent destruction of the dinosaurs, followed by the their replacement with small mammals, altered forever the progress of human evolution. This book presents a fascinating glimpse through the lens of the natural sciences - the geology, climatology, and oceanography, of the effects of an enormous astronomical event.

Disk contains: HAZARDS version 5.5, designed to predict asteroid or comet impacts with the Earth.