Bangalore: India is among one of the 10 countries that are most at risk of being wiped out by an asteroid. China and the United States also appear in the list. NASA’s Wide-field Infrared Survey Explorer has made possible one of the best assessments of our solar system’s population of potentially hazardous asteroids (PHA).
The explorer sampled 107 ‘’potentially hazardous’’ asteroids, to determine how many are out there – and the figure is a frightening 47,000! PHAs have orbits closest to that of Earth’s and are big enough to withstand passing through the Earth’s atmosphere.
The results come from NEOWISE, the asteroid hunting portion of the WISE mission. According to Nick Bailey of the University of Southampton’s School of Engineering Sciences team, “The threat of the Earth being hit by an asteroid is increasingly being accepted as the single greatest natural disaster hazard faced by humanity.”
Bailey and his colleagues conducted a study to rank each country based on the frequency and severity of the catastrophe caused by each impact. The software called the NEOimpactor measures the impact of ‘small’ asteroids under one kilometer in diameter.
The countries most affected in terms of population lost are China, Indonesia, Japan and the United States; while in terms of infrastructure destroyed and the resulting economic loss are United States, China, Sweden, Canada and Japan.Overall, countries that are most at risk are: China, Indonesia, India, Japan, the U.S., the Philippines, Italy, the U.K, Brazil and Nigeria.
“The consequences for human populations and infrastructure as a result of an impact are enormous,” Bailey said. He added, “Nearly one hundred years ago a remote region near the Tunguska River witnessed the largest asteroid impact event in living memory when a relatively small object (approximately 50 metres in diameter) exploded in mid-air. While it only flattened unpopulated forest, had it exploded over London it could have devastated everything within the M25. Our results highlight those countries that face the greatest risk from this most global of natural hazards and thus indicate which nations need to be involved in mitigating the threat.”
“The NEOWISE analysis shows us we’ve made a good start at finding those objects that truly represent an impact hazard to Earth,” said Lindley Johnson, programme executive for the Near-Earth Object Observation Programme at NASA. “But we’ve many more to find, and it will take a concerted effort during the next couple of decades to find all of them that could do serious damage or be a mission destination in the future.”