Simplify the following text for a Grade 12 native English-speaking person.
Original: Optical observations have also determined that Elektra 's shape is quite irregular , as well as giving indications of albedo differences of 5-15 % on its surface .
Simplified: Optical sightings have also determined that Elektra 's shape is quite non-spherical , as well as giving indications of albedo differences of 5-15 % on its surface .