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at The beginning of its discovery it was thought that Ceres it was in fact a “simple” piece of rock “caught” in time, frozen in the moment of the beginning of the creation of the Solar System . With time, this world located in the asteroid belt between Mars and Jupiter, is categorized within dwarf planets -and the only nearest Neptune – and as the asteroid largest in our cosmic neighbourhood. And still she kept more secrets: the space probe Dawn , the NASA , drew so near that he discovered in Ceres a oceanic world.
it All started at the beginning of 2015, even before Dawn came to orbit the dwarf planet. The probe recorded points unusual and abnormally bright in Occator , an impact crater 20 million years. Soon after, scientists noted that these patches of light were created by sodium carbonate , a kind of salt.
This substance is found in the Earth around hydrothermal vents, in the depths of the ocean, where the heat is seeping from the cracks of the seafloor. Although they are far from the light of the Sun, which allows the photosynthesis of which depends the greater part of the life in our planet, these vents are filled with organic beings , a food chain that is dependent on chemosynthetic bacteria that harness chemical reactions, rather than sunlight, for energy. In fact, the scientists believe that organisms of this type could survive in some environments on other planets and could be the key to finding life outside the Earth.
Water stable on the surface
But the source of the sodium carbonate of Ceres is still a topic of debate. In 2016, were presented to six concurrent studies that showed evidence of the presence of criovolcanes , ice water and stable on the surface and strange charged particles caused by the solar wind in Ceres. For this reason, perhaps, came from this kind of salt alien from the ice of the subsoil, which melted with the heat of the impact of Occator, only to re-freeze later? Or there was a layer of brine deep in the moment of impact that leaked to the surface, suggesting that the interior of Ceres was warmer than we thought? And what about that brine could follow you there?
Now a new batch of articles published in various magazines of “Nature” believe that they have found the answer to the last two questions: a rontundo ” yes “.
The precipitous drop Down
the first of The articles, published in “Nature Astronomy”, is based on the data analyzed were compiled in the final phase of the mission Dawn. Left without fuel, the spacecraft plummeted to an altitude of a little less than 35 kilometers, collecting data with a resolution spectacular: a 10-fold higher than the main mission, in addition to a particular focus in the crater Occator.
With this resolution, Dawn failed to register variations of gravity in the crater, combined with the thermal modelling, suggest density variations consistent with a reservoir, deep brine below the crater. This deposit could have been mobilized by the heat and the fracture that resulted from the impact, did that spring upward and outward to create the salt deposits we see today.
“we Further found that the cracks tectonic pre-existing may provide pathways for brines deep migrated within the cortex, extending to the regions affected by the impacts and by creating heterogeneity in the composition,” the authors write.
geological Activity recent and hidrohalita
A second study, published in the same journal, found that the crust of Ceres is fairly porous, but that this feature decreases with depth, possibly as the rock is mixed with the salt. Although the crater is around 20 million a year s, there is evidence that suggests that the salts at the top are much, much younger. The high-resolution images indicate that the volcanoes of ice, Ceres may have been active as recently as 2 million years ago, millennia after the heat of the impact had been dissipated, which indicates a deep source of brine.
And this is supported by a discovery surprise: the presence of hidrohalita , a common mineral in sea ice in the Earth, but had never met outside of here. Spectrometry revealed this hydrated form of sodium chloride in the upper part of the dome of Cerealia Facula, the brightest spot in the crater Occator. The curious thing about this mineral is that it requires moisture and become dehydrated pretty quickly; according to the team’s calculations, in the tens to hundreds of years. This suggests that it must have emanated from the interior of Ceres short time ago.
But the deposition of different salts on the surface has another implication: they could come from a different sources . In the first instance, the heat of the impact melted a lot of ice, that flowed and altered the terrain within the crater, depositing salts in Cerealia and Pasola Faculae. Then, more slowly, and the brine from a reservoir deeper, clawing toward the surface, contributing to increase in Cerealia and Pasola, and creating Vinalia Faculae, a cepósito smallest on the floor of the crater.
So, Ceres is much more strange and complex than we knew, joining the moons, such as Europe , Ganymede , Callisto , Enceladus , Titan and Mimas , and the dwarf planet Pluto, as potential worlds ocean. But how it was formed Ceres and where it came from are still mysteries. Now, we can add the riddle of how to retain enough heat to support an underground reservoir or an ocean.
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