It was called the snowman as Ultima Thule resembled two spheres sitting on top of each other but those have now been defunct due to the new images.
Mr Stern said: “We had an impression of Ultima Thule based on the limited number of images returned in the days around the flyby, but seeing more data has significantly changed our view.
“It would be closer to reality to say Ultima Thule’s shape is flatter, like a pancake.
“But more importantly, the new images are creating scientific puzzles about how such an object could even be formed.”
READ MORE: NASA Ultima Thule pictures: New Horizons snaps new images of asteroid