[FOUNTAIN] A Deadly Game of Space Golf

On June 30, 1908, a large fireball flew over the forest in the Tunguska region of Siberia. It exploded at a point eight kilometers above the ground. The coniferous forest, covering an area over three times that of Seoul, went down like matchsticks due to the wave of the impact. The fire caused by the explosion reduced 2,000 square kilometers of the surrounding area to ash. The explosion was 1,000 times more powerful than the nuclear bomb dropped on Hiroshima.

The Tunguska event was a mystery because no impact crater or remnants of the exploding object were found. Isaac Asimov, a science writer, wrote about the Tunguska mystery in the 1980s. If such explosion had occurred in Moscow or Washington, it would immediately have been believed to be a nuclear attack by an enemy, Mr. Asimov wrote. In 1996, scientists found the answer; they said that an asteroid with a diameter of 60 meters approached the Earth's atmosphere at a shallow angle, exploding into small pieces on entry.

There are 139 traces of large-scale clashes with extraterrestrial objects. The most famous is a crater 195 kilometers wide found on Mexico's Yucatan Peninsula, formed when a comet with a 12-kilometer diameter crashed into the Earth about 65 million years ago. The changed weather caused by the resulting blaze and dust resulted in the extinction of 70 percent of life on Earth, including dinosaurs.

According to scientists, there are about 2,100 "time bombs" with diameters over 1 kilometer traveling close to the Earth's orbit. Although the probability of an impact is extremely low, if it did occur there would be an astronomical number of victims.

Measures to guard against this possibility might be detecting objects on an impact course as early as possible and altering their orbits using nuclear bombs. This scenario has already played out in such movies as "Deep Impact" and "Armageddon."

A foreign news service speculated Sunday that such asteroid-directing methods could be used for aggressive military purposes. By exploding a series of nuclear bombs on an asteroid, it could be guided toward a target area on the Earth. A researcher at Spaceguard, a British organization that studies the threat posed to Earth by foreign bodies, confirmed such a tactic would be possible today. In this deadly space golf, about 15 "putts" － nuclear explosions to change asteroid orbits － would allow the "player" to put the ball in the hole. The cost would be less than that of developing an international space station: $100 billion.

We hope countries at technological frontiers direct their research to planning how to guide asteroids away from the Earth, not toward it.

by Cho Hyun-wook