After analysis by Elliot, Person, and colleagues at MIT, the conclusion was clear: 2002 TX300 (also known as 55636 in the numbering scheme of asteroids and other small bodies in the solar system) was much smaller than had first been thought. Its radius is about 89 miles, with an uncertainty of only three miles (143 kilometers with an uncertainty of only five kilometers). Since it is so small, it must be reflective and covered with ice to appear as bright as it does.