Organic substances found on Ceres by the Dawn probe most likely originated on a dwarf planet, and were not brought there by other asteroids or comets, scientists from the North-Western Research Institute (SwRI) said at the 49th annual meeting of the Planetary Sciences Department of the American Astronomical Society.
Source Spot with a high content of organic substances in the area of the Ernutet crater at Ceres.
The interplanetary Dawn ("Dawn") launched from the Earth 10 years ago, in September 2007, visited the asteroid Vesta, and from 2015 explores the dwarf planet Ceres. Here he found, in particular, incredibly bright white spots, probably consisting of salt deposits and cryovolcano five kilometers high. The data obtained with a visible and infrared mapping spectrometer on board the probe showed that on the surface of Ceres, near the 50-kilometer Ernutet crater, there is a spot saturated with organic matter covering an area of about a thousand square kilometers.
In particular, scientists have discovered the spectral lines of methyl (CH3) and methylene (CH2), the functional groups typical of aliphatic hydrocarbons, similar to terrestrial minerals - asphaltites and kerites. Organics could be brought to Ceres with small asteroids or arise on the spot. Our answers to this question depend on our understanding of the history of the solar system, the way in which organic substances appear and, ultimately, the appearance of life.
The group, led by Simone Marchi, decided to find out whether asteroids or comets could deliver organics to Ceres. With the help of computer modeling, they calculated the parameters of the fall on a dwarf planet of objects of different sizes and different initial velocities.
The results of calculations showed that comets must fall on Ceres at too high a rate - organic molecules could not withstand such high pressures and temperatures. Asteroids, however, had to fall at a lower rate, and in this case, about 20-30 percent of the original organics could remain intact. However, "spots" with a lot of organic matter are located on Ceres not at all in regions where small asteroids of the main belt can fall.
"These data show that organics, most likely, originated at Ceres," says Marci.
Interplanetary vehicles found in the solar system many traces of organic compounds in the solar system. In the list of celestial bodies "organic" organic - Mars, Titan, Sedna, Enceladus and Pluto, and in addition, Comet Churyumov-Gerasimenko.