Ultima Thule is more pancake than snowman, NASA scientists discover

Feb. 11 (UPI) -- Ultima Thule is flatter than scientists originally thought.

As revealed by the latest images captured by NASA's New Horizons spacecraft, only recently downloaded and analyzed by mission scientists, the Kuiper Belt object is more pancake than snowman.

The new images were some of the last New Horizons snapped as it zoomed past the distant object at a speed of 31,000 miles per hour. The new photos offered scientists a new perspective of the minor planet -- the first contact binary to be explored by spacecraft.

By combining the perspectives offered by a handful of images, scientists confirmed Ultima Thule's two lobes aren't spherical. They're relatively flat.

Scientists found the object's larger lobe is shaped like a fluffy pancake, while the smaller of the two lobes recalls a "dented walnut."

"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," Alan Stern, principal investigator on the mission and scientist at the Southwest Research Institute, said in a news release. "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. We've never seen something like this orbiting the sun."

The new images weren't very clear. New Horizons' camera was forced to use a longer exposure time to capture the photos, blurring the images. But NASA scientists were able to sharpen the images.

Only half the object's peanut-like shape is visible in the photo series, which at first, make it difficult to appreciate the object's shape. But by tracking which background stars became blocked by the dark Kuiper Belt object, scientists were able to trace the object's outline.

"While the very nature of a fast flyby in some ways limits how well we can determine the true shape of Ultima Thule, the new results clearly show that Ultima and Thule are much flatter than originally believed, and much flatter than expected," said Hal Weaver, a New Horizons project scientist from the Johns Hopkins Applied Physics Laboratory. "This will undoubtedly motivate new theories of planetesimal formation in the early solar system."