Asteroids are large space rocks that have been floating in space since the Big BangAccording to many scientific theories, Big Bang is the event of the expansion of matter from a highly dense singularity and it marks the beginning of the universe.. Some of those asteroids are hovering close to our planet. NASA has data about more than 90% of asteroids floating close to Earth. In this lesson, we’ll look at the endpoints that provide us access to this information.