Simplify the following text for a Grade 8 native English-speaking person.
Original: Themisto was first discovered by Charles T. Kowal and Elizabeth Roemer on September 30 , 1975 , reported on October 3 , 1975 , and designated ' .
Simplified: Themisto was first found by Charles T. Kowal and Elizabeth Roemer on September 30 , 1975 , reported on October 3 , 1975and designated ' .