Asteroid 2012 DA14, which will make its close approach February 15th at 2:24 p.m. EST, will not be visible to the human eye or to those in the United States. It will be visible to observers in Eastern Europe ranging to Australia with binoculars or a telescope.
It was discovered by Spanish astronomers last year and its orbit was determined to be similar to Earth's. The good news is that this close call will change the orbit of the asteroid and take it further away from us, reducing the chance of a future impact.
If this asteroid were to enter the atmosphere, it is theorized it would explode in the atmosphere with the equivalent of a 2.4 megaton blast. This close call will give scientists the opportunity to study the rock's composition and how it is moving through the solar system.