The Faculty of Physics at the Technion, in collaboration with German scientists at Tübingen explains the unique properties of Arrokoth which shed new light on the formation of other asteroid-like objects in the Kuiper Belt, and understanding the early stages of the formation of the solar system.

The first photos of "the snowman", known formally as Arrokoth were taken by NASA's New Horizon space mission. They published their findings in Nature.

The adventures of NASA's New Horizon

The New Horizons robotic spacecraft was sent to investigate Pluto's features and terrain. It fixed its trajectory towards Pluto, starting a long journey of about nine years but most of its systems were in sleep mode until it was close to its target to save fuel and resources.

When it woke up, Pluto was no longer considered a planet after the International Astronomical Union decided to demote the Pluto into a dwarf planet. But the importance of the New Horizon's mission is still valid as it provided spectacular images of Pluto and its moon Charon.

It also provided invaluable scientific information that is still investigated until now and will likely be investigated for many more years. The information gathered by the New Horizon gives important input for understanding the Kuiper Belt.

Kuiper Belt lies beyond the Neptune which consists of innumerable asteroid-like objects ranging in size from a few feet thousands of miles. The objects seen in the Kuiper Belt are typically icier as they have a colder condition than their "sister" asteroid belt.

But the New horizon found more objects in the Kuiper Belt. So, the scientists designed the trajectory for the New Horizon so that it would pass to the newly found object after it completes its initial mission of mapping the Pluto.

On January 1, 2019, as the New Horizons spacecraft passed by it just 3,500 miles away, humanity took its first close-up shot of a small Kuiper Belt object.

Arrokoth the snowman

Upon the first arrival of the images of the object found in the Kuiper Belt, the researchers initially called it Ultima Thule or in Latin, "The Edge of the World," because of its remote location at the edge of the solar system. But renamed it 486958 Arrokoth, which means "sky" or "cloud" from the now-extinct Powhatan Native American language.

Arrokoth is a 30-kilometer contact binary with two differently sized lobes interconnected by a thin neck. The Arrokoth appears to be the product of two smaller Kuiper Belt objects that collided.

Various models have been proposed to explain the formation of Arrokoth and its unique properties, encountered major challenges, and in particular, its rotation speed around itself and its large inclination angle.

Technion researchers, Evgeni Grishin who is a Ph. D. student, postdoc Dr. Uri Malamud, and their supervisor Professor Hagai Perets, in collaboration with the German research group in Tübingen presented their new analytic calculations and detailed simulations explaining Arrokoth's formation and features.

They also studied how robust and probable the processes of the formation of Arrokoth, and found them to potentially be quite common with 20% of all Kuipler Belt binary objects. But until now, it is still impossible to explain the Arrokoth's unique features.