 And scientists are saying not to worry about two giant asteroids hurtling toward Earth. The European Space Agency says an asteroid over a mile wide will be zipping by the Earth this afternoon at a relatively close 4 million miles away, posing no threat. They say it's the closest flyby on record of an asteroid that large. And Saturday, another huge asteroid will zip past. A recently discovered asteroid smaller, about 800 feet wide, but will be closer at 180,000 miles from Earth. Scientists can say there's no risk of hitting us, but at the same time noted if it did, it would cause damage.