As the asteroid moved nearer to Earth, on Jan. 28, the Arecibo Observatory in Puerto Rico working with the Robert C. Byrd Green Bank Telescope in W. Va. produced another image of the asteroid. Astronomers used the Arecibo telescope, which is operated by Cornell University on behalf of the National Science Foundation, to bounce radar signals off the asteroid. The Green Bank Telescope received the echo signal and transmitted the data back to Arecibo to be transformed into an image.

Other radar telescopes were expected to point toward the asteroid as it made its closest approach to Earth, 334,000 miles (537,500 kilometers), at 3:33 a.m. Eastern time Jan. 29. For comparison, the moon is an average of 239,228 miles (385,000 kilometers) away.

"We have good images of a couple dozen objects like this, and for about one in 10, we see something we've never seen before," said Mike Nolan, head of radar astronomy at the Arecibo Observatory. "We really haven't sampled the population enough to know what's out there."

Those Atari 2600 programmers were way ahead of their time.