New Horizons probe reveals distant Ultima Thule asteroid looks like a snowman

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Flyby data have already solved one of Ultima's mysteries, showing that the Kuiper Belt object is spinning like a propeller with the axis pointing approximately toward New Horizons.

"What this spacecraft and this team accomplished is unprecedented", said Alan Stern, the mission's principal investigator, before unveiling the first images.

This is consistent with other irradiated objects that are in the Kuiper Belt, Carly Howett, mission co-investigator at the Southwest Research Institute, said yesterday.

Names matter, even when they're temporary nicknames for objects 4.1 billion miles (6.6 billion kilometers) away from Earth. The New Horizons team thought it was an apt term for MU69, the spacecraft's next target beyond Pluto. He called New Horizons "a time machine", capable of taking scientists back to the moment of our origins. "If you had a collision with another auto at those speeds, you may not even bother to fill out the insurance forms", he said. It likely formed over time as a rotating cloud of small, icy bodies started to combine. A distant object now actually feels real to everyone here on Earth. The area has hundreds of thousands of objects that could hold the keys to understanding the beginning of our solar system. And different models produce different outcomes.


We have a lot more data to download from New Horizons over the coming months at the painfully slow rate of one kilobit per second. Studying it could offer insights to how Earth and the other planets formed.

Still, he said, when all the data comes in, "there are going to be mysteries of Ultima Thule that we can't figure out". The new images revealed that the object is in fact a contact binary, consisting of two spheres that measure 31 km (19 mi) from end to end.

Ultima Thule has a mottled appearance the colour of boring brick. The two objects were slowly pulled together by gravity, creating the "bilobed" object with a distinct "neck". The larger lobe is the "bottom" sphere and the smaller lobe is the "upper" sphere.

After New Horizons has had a chance to get closer to the object, to determine more about its characteristics, NASA scientists will decide on a permanent name.


Pre-flyby observations made by the Hubble Space Telescope indicated that MU69's surface was red in color, and that has proven true - with the reddish hue indicating the presence of tholins, which are processed volatile ices.

As Helene Winters, New Horizons' Project Manager, indicated, it won't stop there.

NASA researchers promised fresh announcements would drop Thursday, including on the composition and atmosphere of Ultima Thule, as new images with even more precise resolution have come through. It appears not to have any impact craters.

The first color image of Ultima Thule, taken at a distance of 137,000 km (85,000 mi) at 04:08 am UTC on January 1st, 2019. In 2015, the spacecraft passed Pluto, providing the first images of a world once considered our ninth planet.


We may never, never reach them.

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