Simplify the following text for a Grade 8 native English-speaking person.
Original: In 1989 , Triton was the coldest object that had yet been measured in the solar system , with estimated temperatures of â ' 235 Â .
Simplified: Triton is the coldest object that has been measured in the solar system , with temperatures of â ' 235 Â C ( 38 K , â ' 392 Â F ) .