Something like this:

This video was made from 72 radar observations made on the night of Feb. 15/16, 2013, by NASA scientists using the 230-foot (70-meter) Deep Space Network antenna at Goldstone, CA. The target object, a ~40-meter wide asteroid named 2012 DA14, passed within 17,200 miles (27,680 km) of Earth — coming several thousand miles closer than many communication satellites.

It was the closest observed pass of an object of its size.

These images are preliminary observations and thus are still rough, but we do get an idea of the shape of the now-famous DA14… basically an angular, elongated ovoid shape with some radar-bright bumps. A space yam, if you will.

The tubers are out there.

From JPL:
The observations were made as the asteroid was moving away from Earth. The asteroid’s distance from the radar dish increased from 74,000 miles (120,000 kilometers) to 195,000 miles (314,000 kilometers). The resolution is 13 feet (four meters) per pixel. The images span close to eight hours and clearly show an elongated object undergoing roughly one full rotation. The images suggest that the asteroid has a long axis of about 130 feet (40 meters).

Radar is a powerful technique for studying an asteroid’s size, shape, rotation state, surface features and surface roughness, and for improving calculations of its orbit. Radar measurements of asteroid distances and velocities often enable computation of asteroid orbits much further into the future than if radar observations weren’t available.

Find out how radar is used to “see” asteroids here.

The radar observations were led by scientists Lance Benner and Marina Brozovic of NASA’s Jet Propulsion Laboratory, Pasadena, Calif. Additional Goldstone radar observations are scheduled on February 18, 19 and 20.

Source: NASA/JPL