Asteroid with rings - level 2
A giant asteroid surprised scientists who discovered that it had rings.
The asteroid is 250 kilometres wide. It is the smallest known object to have such rings. People used to think that rings are only around big planets like Saturn or Neptune.
The scientists noticed the rings when the asteroid moved in front of the star. It cast a shadow over South America. We don’t know how the rings are formed. One theory says that the rings are made up of ice, small stones and other debris.
Difficult words: used to think (thought), cast (to make), debris (broken pieces of rock).