Simplify the following text for a Grade 9 native English-speaking person.
Original: The photographs taken by Voyager 1 showed Metis only as a dot , and hence knowledge about Metis was very limited until the arrival of the Galileo spacecraft .
Simplified: The images taken by Voyager 1 showed Metis only as a dot , and very little was known about Metis until the arrival of the Galileo spacecraft .