Disintegrating comet dust could to place on the moons of Jupiter the seeds of life. Including in Europe, under the icy shell of which, hopefully, is hidden ocean.
Jupiter's moons are divided into two types: large spherical satellites and less lumpy body with eccentric orbits. Chemical analysis of the past suggests that they are made from a material of asteroids and comets. In other words, they most likely are rich carbon compounds that play a key role in life on Earth.
|Left to right: Europa, Ganymede, Jupiter. (Photo by Mick Hyde.)|
It is believed that the gravity of the planets shuffling that occurred about 4 billion years ago, shook the remote zone space rocks, which is why some of them on a journey towards the Sun. Part is trapped by Jupiter – they were his irregular satellites. Furnished our new location on the objects were often collide, producing a dust-sized particles of coffee powder.
If we believe the model, Jupiter took about 70 million Gt of material, but its mass is irregular satellites half. "Where are the rest?" – Asked myself and colleagues William Bottke of the Southwest Research Institute (USA). Modeling the evolution of irregular moons showed that the dust was fond attraction of Jupiter and the solar wind. About 40% of the material could settle on a large satellite , primarily on Callisto, Ganymede and then, and only then to Europe.
The data obtained in part correspond to the images that are sent by the spacecraft "Galileo": Ganymede and Callisto, and indeed there is a dark material. Mr. Bottke seems that Callisto completely covered with debris, while Ganymede is still lighter.
But the surface of Europa is relatively clean. The cracks in the crust indicate that the surface material is exchanged with the interior of the satellite, so the carbon-rich material could go straight into the ocean, believes Mr. Bottke. "He played a role there? Hard to say. But fun to think about it ", – says the scientist.
Calculations Mr. Bottke establish a lower bound of the number of carbon-containing material that could fall into the ocean in Europe, says Cynthia Phillips of the Institute SETI. "Maybe there were other sources of interest to the astrobiological point of view of the material," – she said.
The study is published in the journal Icarus.
Prepared according to NewScientist.