[link to news.yahoo.com]

On average, objects of that size are estimated to hit Earth about once every 1,000 years.
"From the information we have, we don't know of an asteroid that will threaten the population of the United States," Bolden said. "But if it's coming in three weeks, pray."
In addition to stepping up its monitoring efforts and building international partnerships, NASA is looking at developing technologies to divert an object that may be on a collision course with Earth.
"The odds of a near-Earth object strike causing massive casualties and destruction of infrastructure