Scientists have explained the strange form of "alien" Umuamua asteroid
Last year, the offender interstellar space Umuamua passed through the inner solar system. Initially it was assumed that it was a comet, asteroid and then, and then all the alien ship - the visitor had the properties, unusual for a typical space rocks. He was moving too fast and at an odd angle, to be rooted in our system; either Jupiter or Neptune or the Oort cloud could not send to us an object with these properties. To study in detail the asteroid, scientists have concluded that it is covered with ice inside a kind of carbon, and the asteroid does not leave the tail, despite the temperature of 290 degrees Celsius. What's the strangest thing - is its form of a cigar with a ratio of width to length of 1: 8. They offered a variety of explanations, but ultimately come to the simplest: a journey through the Milky Way billions of years turned the asteroid in the object that we are interested in.
Looking at the solar system today, you can find inner solid worlds, outer gas giants and a handful of smaller objects that are grouped into four different narodtse:
- Asteroids, mineral-rich objects formed near Mars and Jupiter: on the border, where the sunlight will allow the ice formed on the clear light of the sun;
- of the Kuiper belt objects, rich ice objects beyond Neptune formed, which become comets, if included in the inner solar system;
- Centaurs - hybrid objects between the orbits of Jupiter and Neptune;
- objects Oort cloud, which lies beyond the Kuiper Belt and is the remnants from the formation of the solar system.
Although the Kuiper belt objects, and Oort cloud are similar in composition and very numerous in the early days of the formation of the solar system they had a lot more.
Over billions of years, the mutual gravitational interactions between the planets and objects emit a huge amount of the first interstellar space. For every star that is in the galaxy, we will have thousands or millions of objects flying through the universe, is not bound to any star. And just as the stars move relative to the sun at a speed of 20 km / s, the average moves and most of these interstellar intruders.
From a certain point of view, it is striking that we have been looking for their first interstellar asteroid. Probably, such a meeting should take place several times a year, but rarely such large objects appear close enough to the sun so that we could capture them. And when we discovered this asteroid, we immediately surprised by its properties: its rotational movement, the curve of his blackouts, the composition of the surface and subsoil, as well as a strange elongated shape. Rotation was not a surprise, since in the absence of a massive object, which could settle it, an asteroid of this form will rotate. But the other properties remained a mystery.
We have never seen interstellar objects before, so astronomers and astrophysicists are seriously thinking how to explain Umuamua. Some are trying to track his movement in the past, because there is a chance that the asteroid was thrown out of the system recently. Others are looking for an explanation as to how such an elongated object, protected by the carbon could be formed, especially against the background of these shapeless objects that we see everywhere. The simplest explanation is that this icy object flying through the galaxy billions of years, and its interaction with the interstellar medium has transformed it into what we see today.
We believe that space - a void, but in fact it has a lot of dust particles and neutral atoms, ions and cosmic rays, even where there are no stars. As long as the object moves through space at speeds of hundreds of kilometers per second, it is constantly bombarded with numerous small fast particles. Just as water and sand smooth and blur the pebbles and stones in the ocean, the space environment affects just thrown on icy bodies.
Since the objects are rarely spherical, they tend to be extended in one direction more than the other, which leads to an elongated flattened forms. The lightest molecules are cleared quickly and the heavy, have a stronger grid can hold. The presence of carbon components, the bombarded particles means that they may be heated by contacting a more stable molecular configurations, and then freezing. It was so for billions of years could be formed "cigar", which took over the alien ship. If such an object is not close enough to the star to his bowels burst through the crust, we will not see any tail or coma, or behavior of the comet. In addition, most of the external volatiles evaporate over billions of years. Simply, it is unusual for the bodies of the solar system. Modeling of new monitoring and collection of statistics for this new class of objects will eventually provide us with the answer, but until then we can only guess where the "it" flew.