Each frame of the brief movie that captured asteroid 2005 YU55 hurling close the Earth required 20 minutes of data collection, officials said, and gives a first close-up peek into the object the size of a city block.
Researchers at the Jet Propulsion Laboratory, a research arm of NASA in Goldstone, Calif., collected the images from their Deep Space Network antenna as the asteroid passed by the Earth Monday between 2:24 p.m. and 4:35 p.m. EST.
Officials said the images have the highest resolution generated by radar of any near-Earth object. Each pixel represents four meters (13 feet).
The movie shows the small subset of images obtained at Goldstone on November 7 that have finished processing. By animating a sequence of radar images, we can see more surface detail than is visible otherwise, radar astronomer Lance Benner, the principal investigator for the 2005 YU55 observations, said in a statement. The animation reveals a number of puzzling structures on the surface that we don't yet understand. To date, we've seen less than one half of the surface, so we expect more surprises.
Doomsday sayers warned that the asteroid would cause mayhem, a disaster that scientists assured would not happen.
The last time YU55 swung by the Earth was 1976, though astronomers were unaware of the flyby at the time. The next time an asteroid of this size comes close to the Earth will be 2028, NASA officials said.