Simplify the following text for a Grade 4 native English-speaking person.
Original: The most prominent surface feature is Stickney crater , named after Asaph Hall 's wife , Angeline Stickney Hall , Stickney being her maiden name . As with Mimas 's crater Herschel , the impact that created Stickney must have nearly shattered Phobos .
Simplified: There is one large crater on Phobos called Stickney .