Wolf Reimold, a geoscientist at the University of Witwatersrand in Johannesburg, South Africa, said a 1-kilometer-wide asteroid would produce an impact crater of about 12 miles (20 kilometers) in diameter and wipe out an area the size of the United Kingdom. The human toll would depend on where such an impact occurs.
"Estimates may range from 500,000 to 1.5 billion casualties," he said. "This latter number certainly smells of global nuclear war. Such an event would in all likelihood not wipe out mankind, but it would cause a global economic crisis."
Given the real threat of impact by a so-called near Earth object (NEO) and the consequences for human life, Milani and Reimold are urging the worldwide scientific community, and the agencies that fund their research, to take the field of impact mitigation seriously.
