Friday, 26 June 2015

Mysterious “Pyramid” spotted on Ceres

The latest photographs of Ceres taken by the Dawn spacecraft have captured an enthralling pyramid-shaped mountain on the surface in its second mapping orbit, from a height of 2,700 miles. As the spacecraft gets closer, more and more features are beginning to reveal themselves, as mysterious lone mountain discovered towering over the surface of the dwarf planet. The mysterious bright spots appear now as an array of dots scattered across the floor of a crater however their source remains unidentified. Though, six months ago, Ceres appeared as nothing more than a few pixels of light to Dawn, but now it is nearing its closest orbit to the increasingly fascinating dwarf planet. At the end of Dec 2015, the spacecraft will be just 225 miles above the surface and lower than the International Space Station is above Earth. 

Scientists must make do with these tantalizing glimpses of the features that are waiting on the surface. Hence, in one photograph, a pyramid-shaped peak is seen towering over a relatively flat surface. This is very Peculiar Mountain, as there’re few other important features like it in the surrounding again or even the rest of the dwarf planet. However, the structure is believed to rise about 3 miles, almost equal to the height of Mont Blanc in France and Italy, the highest mountain in the Alps. Moreover, in another photo reveals the bright spots in greater detail. More than a few can be seen next to the largest bright area, projected to be six miles wide. Nevertheless the ice and salt are the leading theories for what is causing this odd reflectivity.

Dr Marc Rayman, Dawn’s mission director and chief engineer says; it is really exciting to seeing these features come into sharper focus, as few months ago, when Dawn starts observing its new home from afar, we called it a bright spot. As the explorer closed in and provided better views, we realized it was two bright spots. Now we see these are in many numbers and it’s still not clear what is causing these strong reflections, and I think still more data are required. However, everyone has their own personal favorite theory, but the eventual arbiter is nature. That is, we can all speculate, and we can offer arguments, but the answer is going to be clear soon. Well, my money is on the remnants from ice that has sublimated, and the salts left behind then could be what are reflecting the light. Other photographs disclose the multitude of craters and lines strewn across the surface of this world, situated in the asteroid belt between Mars and Jupiter. Because there’s also evidence for past activity on the surface, including flows, landslides and collapsed natural structures.

Though, Ceres appears to have more remnants of activity than the proto-planet Vesta, which the Dawn spacecraft already studied for 14 months in 2011 and 2012. Therefore, Dawn, which arrived at Ceres on 6th March 2015, is the first spacecraft to orbit two separate bodies in the solar system. It will remain in its current orbit until 30 June, before moving to a lower altitude of 900 miles by early August.  Numerous theories are presently being touted for what the mysterious bright white spots are on Ceres. The Hubble Space Telescope has found over 10 on the surface, but Ceres has found that the two most noticeable - ‘spot 5’ - are in a crater about 57 miles wide.

Moreover, another theory is that they’re salt flats that are reflecting sunlight, left on the surface by saltwater or by other chemical reactions. One more theory is that they’re regions of ice, again reflecting sunlight. It is thought, that Ceres is having plenty of ice beneath its surface, which could be uncovered when an asteroid or comet strikes the surface. The fact these bright spots are in a crater where such an impact occurred actually supports this theory. Therefore, another possibility is that they’re cryovolcanoes - volcanoes that are shooting out water or ice. 

Though, the lack of a raised area around the spots steady with a volcano suggests this might not be correct. And they could even be water vapors ejecting from a liquid reservoir under the ground, though again present observations - namely a lack of extra material close the spots suggests this is not the case.  The surface of Ceres has exposed various interesting and exclusive features.  Just like icy moons in the outer solar system have craters with central pits, but on Ceres central pits in big craters are much more common. These and other features will let to understand the inner structure of Ceres that we cannot sense directly.

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