Although NASA vigilantly searches the skies, dozens of near-Earth asteroids remain undetected, any one of which could strike our planet and cause devastating damage. But better detection will mean more facilities and better equipment — and a lot more money.
Currently, NASA has been able to detect roughly 83 percent of the estimated 940 Near-Earth asteroids that are at least one kilometer in diameter. If such an asteroid were to enter our atmosphere, it could bring with it sun-blocking dust and radical climate change even before it makes an impact. But astronomers are growing more concerned with the more numerous smaller asteroids, whose impact could flatten trees — as happened in Siberia where many astronomers believe a comet or asteroid exploded in 1908 — shatter cities, and cause unpredictable waves of coastal flooding. Because of their size, these asteroids are difficult to detect, and astronomers fear one could strike the Earth with little or no warning.
In 2005, the United States Congress charged NASA to detect at least 90 percent of these smaller asteroids by 2020, but a report from the US National Research Council reveals that achieving that goal will require far more equipment than is currently allotted to asteroid detection. The report indicates that new facilities need to be built, with equipment capable of detecting fainter asteroids and covering a wider range of the cosmos. A better system will need to be developed for detecting asteroids that are particularly close to Earth, rather than simply creating a catalog of near-Earth asteroids, and a telescope would need to be placed at another vantage point in space to detect asteroids coming from the sun.
The NRC is unsure what the cost of these systems would be, but panel leader Irwin Shapiro of the Harvard-Smithsonian Center for Astrophysics believes it is essential to our continued safety:
"There is no free lunch," Shapiro agrees. But he adds, "We're talking about investing in an insurance policy."
Earth could be blindsided by asteroids, panel warns [New Scientist]