Ultima Thule – Distant object discovered

Scientists have been studying a distant object known as Ultima Thule. They are revising ideas about its shape after examining the latest images downlinked to Earth. The pictures, taken by the New Horizons probe on 1 January, show the apparently bulbous body to be quite flat. This interpretation is evident from the data acquired by the Nasa spacecraft when it looked back at icy Ultima Thule as it zoomed past at 50,000km/h.

The small world appears dark apart from a crescent of sunlight along its limb. But scientists can tell from the way background stars blink on and off where its edges are. Rather than being two relatively spherical bodies in contact with each other, Ultima Thule in this new analysis is determined to be much more squashed.

It’s not the snowman lookalike that was initially imagines. The New Horizons science team now says the larger lobe, “Ultima”, more closely resembles a giant pancake; and the smaller lobe, nicknamed “Thule”, is shaped like a dented walnut.

Principal investigator Prof Alan Stern commented that they had never seen something like this orbiting the sun. New Horizons; flyby of Ultima Thule occurred some 6.5 billion km from Earth. The encounter set a new record for the most distant ever visit to a Solar System object by a spacecraft. The rendezvous occurred in a frozen region known as the Kuiper belt. The hope is that Ultima Thule’s structure and composition can reveal new insights on how all planetary bodies came into being just over 4.6 billion years ago.