The world is still vulnerable to a potentially catastrophic asteroid strike, according to President Barack Obama’s chief science adviser.<br />NASA made substantial progress in finding the asteroids that pose the biggest threat to Earth, but there’s still a lot of work to do.<br />We are not fully prepared, but we are on a trajectory to get much more so.<br />This is a hazard that, 65 million years ago, the dinosaurs succumbed to.<br />We have to be smarter than the dinosaurs.<br />While smaller asteroids can do great damage on a local scale, experts think space rocks must be at least 0.6 miles wide to threaten human civilization.<br />NASA scientists estimate they found at least 90 percent of these mountain-size, near-Earth asteroids, and none of them pose a threat for the foreseeable future.
