Why the surface of the asteroid Vesta looks like she was born, but actually Vesta is the age of the Earth? Why is it not recognizing the space weathering? Some astrophysicists explain this by the fact that perhaps Vesta has a magnetic field, which reflects the particles of cosmic dust and solar wind.

It should be noted that small objects in the Solar system like the satellites of the planets or asteroids is not so easy to stay "forever young". Deprived of the magnetic field and are not protected by powerful atmosphere they inevitably grow old because they cuts cosmic dust and meteorites, and the surface undergoes continuous processing particles of the solar wind. Under such impacts is difficult to save "person", that is, the surface in the same form that was peculiar to her at birth small object.

At the same time known asteroid, named after the Roman goddess of the hearth Vesta, when observed from Earth seems forever young, like the goddess. Its surface does not have signs of weathering, and craters on it, not so much. Moreover, the ground of Vesta, when viewed with our planet, it seems very light - and this is a sign that the object is young. And this despite the fact that the age of the asteroid approximately equal to that of the Earth.

Until recently, scientists could not understand where Vesta takes "ambrosia and nectar", allowing her to remain young. However, recent images taken by the probe "Dawn" ("Dawn"), which went into orbit Vesta in July 2011 and left the asteroid in September, has prompted researchers to one interesting thought. The fact that the photographs of the surface of the asteroid, indeed there is no evidence of leakage of space weathering, i.e. darkening of the surface and the shift of spectral signatures towards red.

In addition, according to "Dawn", on the surface of Vesta very little metal balls that are common for most asteroids, and satellites. And they appear as follows: nanoscale iron is produced when particles of cosmic dust or solar wind, falling on the surface of the celestial body, evaporated iron from the existing minerals. After this steam is then deposited in the form of the most metal balls closest to the place of the condensation surface. That is, the presence of these balls says that the celestial body periodically experiences outside influence.

Well, if it is, then the lack of balls, can be interpreted as the fact that dust particles and solar wind West without his visits or at least make this an extremely rare. But how is this possible? Astrophysicist Roger Fu from the Massachusetts Institute of technology (USA) and his colleagues believe that the reason lies in the existence of the magnetic field of the asteroid.

By the way, this assumption is not unfounded - recently, this group of scientists managed to find the characteristics of the magnetic field in the meteorite, which was once part of Vesta. They carefully studied the age and magnetic properties of the sample meteorite ALHA81001, who arrived with Vesta and found in Antarctica in 1981.

Special attention was studied tiny crystals that determine its microstructure, and proved to ferromagnets. It is known that when such crystals are formed in the presence of the background magnetic field, when heated, they are arranged in the direction of this field. To identify the time of the earliest magnetization samples were subjected to successive "degauss" until then, until they were discovered the oldest traces. Their age was equal to 3.7 billion years.

It should be noted that the most ancient imaging (corresponding 2-12 MT, against 65 on the surface of today's Earth) coincided with the age of the meteorite. This means that he was subjected to magnetic influence even on the West, and it was just a few times weaker than on a much more massive Earth. That is, in former times, the magnetic field was there, and power it is not much inferior to the earth. And if this is so, then why it can't be around the asteroid in our days?

And now, combining data "Dawn" with the results of the research of the meteorite, Dr. Fu and his colleagues suggested that, perhaps, Vesta and still has a magnetic field that could protect the asteroid from the solar wind throughout its history. A similar effect can be observed on the moon: where there is a small magnetic field, seen the lighter parts, which contrast with the dark, weathered surface. Unfortunately, so far confirm this assumption through direct research impossible. The matter is that according to the initial plan Dawn had to take a magnetometer, but the over-expenditure of finances forced the designers to abandon this device.

However, many of astrophysics and geologists reacted to the hypothesis of Mr. Fu very skeptical. So, Geophysics reminded that Vesta as our planet was formed about 4.5 billion years ago. If the asteroid and had built Dynamo, i.e. continuous movement of molten metal on the inside of the liquid kernel of the asteroid, it (as the cooling of the internal sections of it) had to stop its work, having existed for a maximum of 100 million years. So now the presence on the West of the magnetic field is unlikely.

And planetology Lindsay Keller from the Space center of NASA them. Johnson (USA) believes that the lack of metal balls just says that the surface of Vesta geologically different from that of other asteroids. According to him, there cortical breed contains much less iron than the moon. Thus the solar wind on the West simply nothing to evaporate - which explains the absence of those balls of iron.

And the fact that the surface of Vesta is not darkened, Karl Pieters of brown University (USA) explains as follows: according to "Dawn", the impacts of large meteorites on the surface of the asteroid result in the release of lighter rocks outside craters, resulting in the formation of bright ay". By the way, the same thing happens on the moon, but there's a space weathering slowly dims them. But on the West they may disappear "themselves", because the surface of the asteroid constantly bombards the rain from micrometeorites. The result is the mixing of old and new material, i.e. ay" disappear, but together with them disappear and traces of weathering.

So, as you see, hypotheses about why Vesta looks like only yesterday she was born, quite a lot. And to understand which one is the right one, so far it is difficult because of the lack of data. Perhaps the answer to this riddle is received after new missions on this mysterious asteroid...