Simplify the following text for a Grade 9 native English-speaking person.
Original: Amalthea was discovered on September 9 , 1892 , by Edward Emerson Barnard using the 36 inch ( 91 cm ) refractor telescope at Lick Observatory .
Simplified: Amalthea was found on September 9 , 1892 by Edward Emerson Barnard using the 36 inch ( 91 cm ) telescope at Lick Observatory .