This image provided by NASA/JPL-Caltech shows a simulation of asteroid 2012 DA14 approaching from the south as it passes through the Earth-moon system on Friday, Feb. 15, 2013. (AP Photo/NASA/JPL-Caltech) CAPE CANAVERAL, Fla. -- The world is safe - at least from one asteroid. A 150-foot cosmic rock hurtled safely past Earth on Friday. Note: Tune into The Channel Channel tonight at 9pm for an encore of Deadliest Space Weather - Meteors. (MORE: Hundreds Hurt after Meteor Hits Earth) It...

The world will have to live with surprise asteroid attacks on the scale of Friday's Russian fireball, at least for a while. The meteor that without warning Friday (Feb. 15), damaging hundreds of buildings and wounding more than 1,000 people, was caused by a space rock about 50 feet (15 meters) wide, researchers said. Asteroids of this size are both difficult to detect and incredibly numerous, so it will take a long time for astronomers to find and map out...

People have a hard time comprehending the size of things we don't encounter in everyday life. These days someone is more likely to compare the size of something to an iPad than to a breadbox, but we still can't often grasp the magnitude of the distance from the Earth to the Sun or the radius of a hydrogen atom. It often helps to put things into a scale that we can better understand. For example, the asteroid 2012 DA14 will...