The asteroid is called Apophis. It's a near-Earth asteroid that is a type called a chondrite, essentially a stony body that has a high silicate content and few metals. It is about 330 meters across, and it's due to pass the Earth in 2029.
Dan Durda, principal scientist in the department of Space Studies at the Southwest Research Institute in Colorado, noted that the the fact that the asteroid was coming so close — no less than about 29,450 kilometers (18,300 miles) away — offers a chance to get a close look. So he sent a proposal to NASA, which is considering a probe to chase Apophis down and do a seismic study as it swings by.