March will be inspired by its neighboring planets despite herself. One of its two moons, Phobos could disintegrate in 20 to 40 million years and debris should then form a ring around it, according to a study published Monday in the journal “Nature”. “Scientists have known for decades that Phobos is slowly approaching Mars at a speed of a few centimeters per year,” says Benjamin Black of the American university Berkeley, co-author of the study.
The orbit of Phobos is a spiral that goes tapering
Phobos is the largest – and the closest – the two moons of Mars, the other being Deimos. Irregular in shape, it measures 27 km in its widest part.
In recent years, Phobos flybys by the European Mars Express have led to speculate on its composition. This moon is essentially composed of a pile of debris, with large spaces between the boulders that make up the interior of the moon. About one quarter to one third of Phobos would consist of empty space.
Moreover, the orbit of Phobos is a spiral which goes narrowing (unlike our moon, which moves away from the Earth), approaching inexorably Mars on which the world will end one day crashing.
“Scientists have known for decades that Phobos is slowly approaching Mars at a speed of a few centimeters per year “, told AFP Benjamin Black of the American university Berkeley, co-author of the study. Benjamin Black and Tushar Mittal, of the University of New York, have deduced what might be the end of the planet, from observational data.
The researchers believe that the less dense components Phobos will eventually disintegrate in 20 to 40 million years when the effect of the gravitational force of Mars will become too high due to the proximity of the two planets. These components will then disperse to form a ring.
The most durable components of Phobos but does not dislocate the planet collide, forming a crater.
According to the study, new ring will accompany Mars for millions of years.
“This ring may have a lifespan of 1 to 100 million years, according to the distance between Mars and Phobos when the moon will crash “says Benjamin Black.
In the solar system, the four giant planets (Jupiter, Saturn, Uranus and Neptune) possess a” ring system “.
According to researchers The future of Mars ring may have a density similar to those of Saturn, composed of dust and ice. The origin of Jupiter’s rings continues to intrigue scientists
The moon of Mars. Phobos
Phobos is a very irregular body dimensions 27 × 21.6 × 18.8 kilometers , far too little mass to be in hydrostatic equilibrium and hence for taking a near-spherical shape ; it is also one of the smaller moons of the solar system. Simply because of its shape, its surface gravity varies from about 210% depending on where it is measured.
Phobos is a dark body that appears to be composed of carbonaceous chondrite, a similar composition that of C-type asteroids in the outer asteroid belt. However, the density of Phobos is too low for it to be entirely composed of rock and has significant uneporosité. It was suggested that Phobos could contain substantial ice reservoir, but the spectral observations have ruled out this hypothesis
The Soviet probe Phobos 2 detected that gas escaped from Phobos small but steady amount. Unfortunately the probe broke down before it could determine the nature of the gas.
In 1989, the Phobos 2 probe was inserted to a quasi-satellite orbit relative to Phobos.
Images from Mars Global Surveyor indicate that Phobos is covered with a layer of regolith at least 100 m thick; we think that it comes from impacts with other bodies, but it is unclear how he could join an object with almost no gravity.
During the summer of 2008, the probe Mars Express has clarified some characteristics of Phobos, the mass and density.
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