5. Its surface has patches of brightness

Ultima Thule is extremely dark and reflects no more than 12% of the light that strikes its surface. For the sake of comparison, potting soil reflects about 10% of its light, Stern said. The surface has three types of bright patches: circular or oval spots; lanes that are either straight or gently curved; and what Stern described as broad, diffused regions. The brightest spots are at the object’s neck — the junction between both lobes — and on Maryland.