Scientists limited the search to the Yucatan Peninsula in Mexico, in 1990. Scientists working for Pemex, Mexico's national Oil Company made reports of "magnetic and gravitational anomalies". These scientists also revealed a crater, 106 miles wide, buried a mile underground. It was found near the village of Chicxulub, which means, "tail of the devil". Current research states that the crater was "not formed by volcanic action". (Allan 65) This crater, of gigantic size, wiped out the dinosaurs and most life on this earth at that time.
How likely is it that it will happen to us? According to Patricia Jackson Brown, it could happen anytime. Scientists estimate that an asteroid, larger than one kilometer across, about "once or twice every million years" hits the earth. This is based on an idea of the "numbers and orbits of earth-crossing asteroids", as well as records of craters on other planets and moons. Asteroids larger than one kilometer carry the threat of global catastrophe, as the dinosaurs discovered. Once every 300 years or so, smaller rocks hit the earth. These asteroids are between 300 feet and one kilometer wide, and their effects are usually limited to where they hit. Most land in water, because the earth is primarily water, and have little effect on humans or other life. An explosion, in the South Pacific, once thought as a nuclear test, marked what is now thought as a small asteroid hitting the water. (Patricia Jackson Brown 42-71) Considering this information, it seems that asteroids hit the oceans more than we realize. Eventually, one of these asteroids will make contact with the land on earth.
It is possible that man could deal with an asteroid. According to Karl G. Casson, NASA has held a conference on how to deal with interception of threatening objects. It is easier to deflect or destroy an object the farther away it is from the earth. "It takes a bigger push to get a closer object to miss the earth".