A sequence of images captured as New Horizons moved away from the object in the Kuiper Belt at a velocity of 50,000 km/hour, taken about 10 minutes after closest approach, show a much flatter appearance.
"Most of the so called "Ultima" is like a big pancake, but smaller, "Tula", reminiscent of a flattened walnut" - the researchers note.
The mission's principal investigator Alan Stern said that the new data raises even more questions about the peculiar structure: "More importantly, the new images are creating scientific puzzles about how such an object could even be formed".
Even after New Horizons said goodbye to Ultima Thule, its final glimpse has revealed something completely unexpected. NASA on Friday released a video compiled using more than a dozen images that show Ultima Thule may actually be, uh, much flatter than initially thought. Especially interested in the outer solar system, Laurel gave a brief presentation at the 2008 Great Planet Debate held at the Johns Hopkins University Applied Physics Lab in Laurel, MD. The "old view" in this illustration is based on images taken within a day of New Horizons' closest approach to the Kuiper Belt object on January 1, 2019, suggesting that both of "Ultima" (the larger section, or lobe) and "Thule" (the smaller) were almost flawless spheres just barely touching each other. Thanks to some processing and tracking which stars are being blocked by Ultima Thule's shape, scientists at NASA were able to get a better estimate of the KBO's body. But as more data were analyzed, including several highly evocative crescent images taken almost 10 minutes after closest approach, a "new view" of the object's shape emerged.
That model seems to indicate that Ultima Thule is strangely flat.
The departure pictures were taken from an unexpected point in comparison to the methodology photographs and uncover integral data on Ultima Thule's shape.
At first, Ultima Thule appeared as a blurry, snowman-shaped smudge in the blackness of space. It first wowed Earth after a New Year's Day flyby that beamed back an image somewhat resembling a space snowman or BB-8.
"The shape model we have derived from all of the existing Ultima Thule imagery is remarkably consistent with what we have learned from the new crescent images", said Simon Porter, Co-investigator for the New Horizons project at the Southwest Research Institute in charge of the effort to model the shape of the KBO. The New Horizons spacecraft has the mission to obtain more information about it, and this is exactly what it managed to do. However, more analysis of approach images and new departure images have changed that view. Ultima Thule is approximately 4.1 billion miles from Earth and about 1 billion miles past Pluto, making it the most distant celestial object ever explored. This is important, because this object, and others like it, are thought to be "pristine planetesimals" like those that served as building blocks for larger objects in the Solar System during its early days, 4.5 billion years ago.