Asteroids

Asteroids

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Asteroids

The Opportunity Within The Threat

By Dr. George Friedman

This message is the 24th in a series of Foundation essays designed to inform the Internet public about the incredible possibilities awaiting us in space.

Since the days of the Apollo moon landings, advances in four previously unrelated scientific fields have combined to give humanity a dramatically new view of a new global danger as well as a new path to the colonization of space.

The astronomers have discovered that the population of asteroids and comets whose orbits cross the orbit of the earth — called “Near-Earth Objects” (NEOs) — is far larger than previously thought. Presently, it is estimated that the set of NEOs include 2000 asteroids larger than 1 km and 300,000 asteroids larger than 100m in diameter.

The geologists have discovered that the remnants of large craters which were formed over the past several hundred million years are generally not of volcanic origin, as previously thought. The vast majority of these craters are now agreed to have been the result of gigantic impacts of objects from space. In particular, the 160 km diameter crater in the northern Yucatan peninsula, appears to be the result of an impact of a 10 km object 65 million years ago.

The atmospheric physicists, working with the so called “nuclear winter” models, predicted that the effect on the biosphere of NEO impacts or nuclear weapons is incredibly more devastating than previously thought. As terrible as the immediate, local effects of such events are, they pale in comparison with the global effect: high altitude dust and opaque particles would circle the entire earth within months and prevent sunshine from reaching the earth for years. Plants would die, animals which eat plants and animals which eat animals which eat plants would starve. Most of earth’s species would perish.

The paleontologists studying the history of life on earth have long been puzzled by the major extinctions which have punctuated evolution several times over the past several hundred million years. In particular, the age of the great dinosaurs — which lasted 200 million years –ended abruptly 65 million years ago when over 70% of all species then living perished. A layer of iridium was discovered at several sites worldwide at precisely the level between the dinosaur fossils below and the mammalian fossils above. Since iridium is commonly found on NEOs and is rare on the surface of the earth, most scientists conclude that the great extinction of 65 million years ago was due to an NEO strike on the Yucatan peninsula.

This interdisciplinary display of detective work by these small, dedicated teams of scientists deserves our deepest respect. It displays the scientific method at its best.

But what do these new insights mean to humanity in general?

To some, our new understanding of NEOs represents a new and supremely dangerous threat to the continuation of our species. It is estimated that NEOs of 1 km or larger will trigger the global effect of high altitude particulates and cause the death of billions of humans as well as millions of other species. Although the annual likelihood of this event is as low as one in a million, the consequence is unprecedented and unthinkable. Major debate exists world wide as to the proper response to this threat.

To others, the existence of the projected NEO population as unexpectedly close neighbors to earth represents a wonderful new opportunity. These bodies can provide a far richer variety of material resources than the surface of the moon, and in many cases require far less energy to reach. This provides a fundamentally new paradigm to augment our previous strategy of employing the lunar surface as our primary space headquarters and source of non-terrestrial material. NEOs may provide at least a major new dimension of humanity’s path to the colonization of space.

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