Simplify the following text for a Grade 9 native English-speaking person.
Original: It was discovered on September 9 , 1892 , by Edward Emerson Barnard and named after Amalthea , a nymph in Greek mythology .
Simplified: It was found on September 9 , 1892 , by Edward Emerson Barnard and named after Amalthea , a nymph in Greek mythology .