Physicists from the Israel Institute of Technology for the first time modeled how the unique asteroid Arrokoth, or Ultima Thule, the most distant object from the Sun that has ever been visited by spacecraft, was formed. The study is published in the scientific journal Nature.
Asteroid Arrokoth is a 30-kilometer contact-double object, consisting of two parts of different sizes. Between themselves they are connected by a small isthmus. In fact, Arrokoth is the result of a collision of two smaller cosmic bodies.
Scientists have been trying for a long time to explain such a strange form of an asteroid and other unusual properties – a slow rotation speed and a large angle of inclination.
If two asteroids collided with each other at high speed, they would collapse. Moreover, if the objects, rotating around each other, would fit smoothly, then the rotation speed of Arrokoth would be much higher than the existing one.
Physicists decided to use a model built on the complex formula of the three-body problem to solve this problem. It turned out that the orbit of the two ancestors of the asteroid gradually transformed from a wide and round to a highly eccentric elliptical and slow. The transformation of the orbit took place under the influence of the sun. Such a trajectory eventually led to a soft collision of two bodies.
Arrokoth is located near the orbit of Pluto, and its size is from 25 to 45 km. Astronomers first discovered a cosmic body using the Hubble orbital telescope. Now the asteroid is out of sight of New Horizons – a probe that has been studying it for a long time. The satellite has already flown deep into the Kuiper belt but continues to transmit data about the asteroid to Earth. It is expected that all 3 GB of information and photographs will be received by scientists no earlier than September 2020.