Giant Asteroid Headed Toward Fly-by of Earth

We're just five days away from an aircraft-carrier-sized asteroid passing less than 202,000 miles from the Earth, a rare near-miss for an object this large, reports ABC News. The object called 2005 YU55 is a circular c-type asteroid—carbon-based, darker than charcoal, and the kind likely responsible for bringing organic materials to Earth. "Without objects of this type, we probably wouldn't be here," said one NASA researcher.

It's the biggest asteroid to pass so close since 1976, when observation technology was much less advanced, so scientists are looking forward to a close-up look at "what it was like when our solar system was forming," says the NASA researcher. The next such fly-by is not expected until 2028. Scientists also say c-type asteroids might also be useful in the future for interplanetary travel, as they often contain water and a compound that can make jet fuel. (More asteroid stories.)