Simplify the following text for a Grade 7 native English-speaking person.
Original: 7066 Nessus ( ; from ) is a centaur ( a type of icy planetoid ) that was discovered by David L. Rabinowitz , working with Spacewatch , at Kitt Peak on 26 April 1993 .
Simplified: 7066 Nessus is a centaur ( a type of icy planetoid ) that was found by David L. Rabinowitz , working with Spacewatch , at Kitt Peak on 26 April , 1993 .