For those who will be watching from the Earth into space through a 40 million years (if there is someone to watch), Mars will be visible at all the way they see it now Terrans.
Scientists have calculated that by the time it will complement the list of planets in the solar system have rings, and will somewhat resemble Saturn.
In an article published in the journal Nature Geoscience , Benjamin Black and Tushar Mittal University of California at Berkeley have shown that the material for the future of the Rings Phobos would be – the larger of the two moons of Mars.
Seek miscalculation of fate Phobos scientists made the realization that internal and Phobos’ orbital characteristics are very different from the parameters of other natural satellites of the planets in the solar system.
known from observations that the orbit of Phobos is not constant, and gradually approaching a satellite to Mars – about 2 meters per century.
«If our moon is moving away from Earth at a few centimeters a year, Phobos a few centimeters closer, so Phobos will inevitably fall on Mars or is broken,” – says Black. In our solar system known only one other moon (Neptune’s moon Triton), which is not deleted, and falls on his planet.
According to the scientists, the study of falling satellites is very important in terms of understanding of the conditions that existed in the early Solar system, where the planets were far more satellites, which later disappeared or fell on them, or were torn and formed concentric rings of debris.
For example, some estimates indicate that 20-30% of the planets at birth should have satellites, gradually falling on them, and condemned to death. Because some of the thousands of Martian craters have formed elliptical Falling debris such Lune.
On the gradual decline and removing them from the satellites of the planets affects one main factor – the tidal interaction. For example, the Moon “late” for the proper rotation of the Earth and therefore causes tides in the oceans and rocks that slow planet.
In this case, the moon itself, the law of conservation momentum, moving away from the Earth.
Phobos is too close to Mars because the planet’s own rotation ahead almost three times. Therefore, the tides caused by Phobos in rocks of Mars, not inhibit, but rather hyping the planet.
The very same Phobos, by virtue of the law of conservation, gradually approaching Mars and its orbital speed increases.
How quickly this happens depends on the number of so-called Love, showing how tough is the planet and how its shape is subject to tidal perturbations. To predict the future fate of the incident Phobos, scientists estimated its hardness – connectedness breeds, of which it is composed. To make it possible, by analyzing the composition of the Martian meteorites on Earth, and most importantly – the form of a 10-kilometer crater Stickney.
Scientists believe that the impact body formed this crater in the distant past, it was almost destroyed Phobos. Calculations showed that the mean density of Phobos is only 1860 kg per cubic meter – in fact, it is a porous pile of stones and dust, which is held in the form of a whole only through gravitational attraction.
Therefore, when approaching Phobos to some critical distance from the planet’s tidal forces from Mars will begin to tear away pieces and throw right and left them in orbit. “If the satellite at a distance of 1.2 crumble radius of Mars, that is 680 km from the surface, it forms a thin ring, comparable in density with one of the most massive Saturn’s rings – says Mittal. – Over time, it becomes wider and reaches the upper limits of the atmosphere will begin to lose the substance falls on Mars ».
If Phobos will fall apart before that, the ring can survive up to 100 million years, scientists have calculated. According to Mittal, it is difficult to predict whether the rings of Mars seen from Earth, as they will be icy, like Saturn, and do not reflect much light. However, they will definitely cast a shadow on the planet that can see through a telescope.
The calculations showed that the destruction of the satellite can be expected in 20-40 million years.
The theme of fate Phobos in scientific publications emerges for the second time in two weeks. At the recent annual meeting of the American Astronomical Society astronomer Terry Goddard center of Herford NASA shared his calculations that Phobos has gradually began to decay.
For a long time it was thought that the long and deep furrows on the surface of Phobos – a crack that crawled from the impact crater Stickney. However, the simulations showed that the crack – in fact breaks in the surface of the satellite, which is literally “bursting at the seams”, torn by the tide of Mars. Then Phobos, scientists have left to live a little longer – 30-50 million years old.
The phenomenon of the slow fall of Phobos to Mars in an unusual way connected with the name of the famous Soviet astrophysicist Iosif Shklovsky. On reducing the satellite it became known in the late 1940s, and in 1959, Shklovsky suggested that if it is caused by inhibition of Phobos on the upper atmosphere, the Phobos at its size should be hollow!
At the same time Shklovsky expressed seeming fantastic hypothesis is now,
that Phobos is a steel sphere with a wall thickness of 6 cm, ie artificial satellite.
The hypothesis Shklovsky received approval among many scientists, however, observations made in 1970, showed that the reduction of Phobos is slower than previously thought, and not under the influence of the atmosphere, and iz for tidal wave traveling across Mars.
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