A new finding has determined that the outer solar system appears not as crowded as some theories suggest, with astronomers unable to find small chunks of rock and ice in the region, which they were expecting to locate. The search in question, the Taiwanese-American Occultation Survey (TAOS), spent two years periodically photographing portions of the sky to look for small chunks of rock and ice orbiting beyond Neptune, in a region of the solar system called the Kuiper Belt.
The survey targeted Kuiper Belt objects (KBOs) with sizes between 2 miles (3 km) and 17 miles (28 km). Since such objects are too small to see directly, the survey watched for stars to dim as KBOs passed in front of and occulted them. … The outer solar system hence appears not as crowded as some theories suggest, perhaps because small KBOs have already stuck together to form larger bodies or frequent collisions have ground down small KBOs into even smaller bits below the threshold of the survey. – phenom