This latest video from Nasa shows the updated Radar movie of “asteroid” 2005 YU55.
“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.”
Each of the 28 frames required 20 minutes of data collection by the Goldstone radar. At the time of the observations, 2005 YU55 was approximately 860,000 miles (1.4 million kilometers) from Earth. The resolution is about 13 feet (4 meters) per pixel. 2005 YU55 takes approximately 18 hours to complete one rotation, so the rotation in the movie appears much more rapid than the actual asteroid rotation speed.
The Goldstone observations utilized a new system to obtain images with a resolution of 4 meters, which is five times finer than the highest resolution previously possible at Goldstone.
“The encounter with 2005 YU55 has produced an enormous amount of data that is still being processed.” said radar astronomer Lance Benner, the principal investigator for the 2005 YU55 Goldstone observations, from NASA’s Jet Propulsion Laboratory in Pasadena, Calif. “The sequence of images we obtained shows unprecedented fine-scale detail on this asteroid, which is comparable in size to the Empire State Building. The Goldstone images show evidence for concavities, a ridge near the asteroid’s equator, and numerous features that may be large boulders.”
The diameter of the object is roughly the same measurement as the height of the Empire State Building, but the volume is much much greater. They are obviously not large boulders since the object (although bigger than NASA said in the previous sentence) is not so big as to be meaningfully self gravitating. There would be nowhere near enough gravity to get the spheroidal surface.
Next, someone should calculate the centripetal acceleration on the inside surface of the object (assuming it is mostly hollow) for the measured axial rotation. If it comes close to 1 g, one could draw even more
Of course NASA, DARPA and the rest of the Worlds military will have taken as much footage as possible of this mysterious object. No doubt plans are being hatched to send a spacecraft up to visit the object as soon as they have processed the masses of information.
Keep in mind that at the constant acceleration of 1 g it would be possible to travel around the galaxy in 200 human years. Of course that would work out to about 200,000 earth years due to relativity so any civilisation that existed at the launch time would be gone by the time you arrived back in the region.