A confirmation that the organic materials found on Ceres formed on the dwarf planet

The Ernutet crater and the organic materials (Image NASA/JPL-Caltech/UCLA/ASI/INAF/MPS/DLR/IDA)
The Ernutet crater and the organic materials (Image NASA/JPL-Caltech/UCLA/ASI/INAF/MPS/DLR/IDA)

In the course of the Conference of the American Astronomical Society’s 49th Division for Planetary Sciences Meeting, SwRI (Southwest Research Institute) scientist Simone Marchi presented the results of a study on the origin of the organic compounds discovered on the dwarf planet Ceres by NASA’s Dawn space probe. There were some doubts about the possibility they had formed on Ceres but according to Marchi and his team the evidence they collected that’s the most likely theory.

The detection of organic materials on the dwarf planet Ceres was described in an article published in February 2017 in the journal “Science”. That research concerned various areas including the one near the Ernutet crater, shown in the image along with a bar indicating the concentration of the organic material detected. The inset shows Ernutet at a higher resolution with areas where there’s the highest concentration of organic materials shown in red.

The hypothesis that the organic compounds detected by the Dawn space probe formed on Ceres was considered most likely by the authors of the research published in February. The researchers referred to a possible complex prebiotic chemistry that took place in a period of Ceres’ history where conditions were favorable.

Simone Marchi’s team also looked at the possibility that the organic compounds were brought to Ceres from the outside but in their opinion none of the two scenarios answered their doubts so they thought that there was some critical piece in the puzzle missing. To try to better understand the issue, they decided to study the possibility that asteroids or comets carried those materials.

The researchers created simulations using the iSALE (impact-SALE) software written precisely to simulate impacts testing a number of different parameters for the virtual crashed objects and their velocity. The results indicate that comet-like bullets with high impact speeds would lose almost all organic materials due to compression shock. Asteroids, with lower speeds, can retain between 20% and 30% of organic materials following the impact but their distribution on Ceres doesn’t match that possibility.

In the end, Simone Marchi’s team also concluded that probably the organic compounds discovered by the Dawn space probe formed on Ceres. This time the researchers started their study from a different angle, meaning that they examined the possibility that they came from outside instead of studying the geology of the regions rich in those compounds.

The issue hasn’t yet been closed but new evidence would be needed to reverse the conclusions of these researches. The Dawn space probe keeps on orbiting the dwarf planet Ceres collecting more data and NASA just announced a second extension of its mission. Dawn is scheduled to go down to even lower altitudes, even under 200 kilometers (120 miles), to try to capture some more details that could be important in the various researches on Ceres.

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