Simplify the following text for a Grade 11 native English-speaking person.
Original: At least 5 stellar occultations by Hygiea were tracked by Earth-based observers , but all with few observing independent measurements so that much was not learned of its shape .
Simplified: At least 5 stellar occultations by Hygiea were tracked by Earth-based observers , but all with few seeing independent measurements so that much was not learned of its shape .