the Most distant object ever visited by the spacecraft, is almost unchanged since the birth of the Solar system. New data about it has helped scientists to see deep into the past and to understand the mechanisms of formation of planets.
Achievement is described in three research articles (1, 2, 3), published in the prestigious journal Science.
the Probe “New horizons” (New horizons) 1 January 2019 flew in the vicinity of the object Arrarat, previously informally known as Ultima Thule . Thus he became the most distant celestial body ever visited by the spacecraft.
a Small object on the outskirts of the Solar system – a real gift for astronomers who want to understand how the planets were formed. After all, he’s barely changed since its birth.
a Modest mass of a celestial body means that gravity is not launched inside the active geological processes, drastically changed the substance of the planets. Besides images show that its surface few impact craters. In other words, we see Arrarat almost as it was born.
Using the most detailed information on shape, topography and chemical composition of celestial bodies, the researchers, apparently, responded to the question specialists for decades. This is the question of the origin of planetesimals – the embryos of planets.
One theory says that a dust cloud on the future site of planetesimals gradually shrinks under its own gravity. This substance is formed in the embryo of the future of the planet. In the cloud could form a few large bodies, which gradually coalesce with each other.
the Alternative model implies a much more rapid process. Small objects formed from dust in different parts of the Solar system, and then collide at high speed. As a result of these collisions is planetesimal. Thus, it consists of numerous fragments, formed far away from each other (as the taleANO, the classic, “if the lips of Nikanor Ivanovich so put to the nose of Ivan Kuzmich…”).
after Collecting all possible data and recreating for them the story Arracacha, the researchers confidently made a choice in favor of the first theory.
As you know, is a celestial body looks as though it consists of two stuck together among themselves the individual objects. It is this event, according to new research took place in the history of the heavenly bodies.
According to scientists, two parts Arracacha formed close to each other and moved relative to each other at low speed. Turning around a common center of mass, they gradually approached each other and in the end smoothly “docked”.
this script specifies a set of features. First, both parts of the celestial bodies have practically the same composition. This means that they were formed in a relatively small dust cloud.
second, the equators and poles of both elements extremely well coincided with each other. It is easy to explain if they played slow orbital dance, allowing gravity to align them. That would just be an incredible coincidence if one of them rushed at high speed from the far edges and the fly crashed into another, as suggested by a rival theory.
Finally, as already mentioned, on the surface of Arrogate almost no impact craters. So he wasn’t bombarded with fast objects.
the Planetary scientists suggest that the scenario of formation of this distant celestial body can be shared not only for the Solar system, but also for the whole cosmos.
“New horizons is striking, as they change our knowledge and understanding of how planetary bodies are formed in solar systems throughout the Universe,” says Lori Glaze (Lori Glaze), the Director of the Office of science about the planets from NASA.
However, one cannot exclude the fact that the scenario of formation of planets and smaller bodies are very diverse. Whether so it, will show new devices and nmarketing future research.
By the way, before “News.Science” (nauka.vesti.ru) wrote about how scientists revise theories of planet formation.