2023-10-17 13:31:13
Dwarf planet Ceres – NASA
MADRID, 17 Oct. (EUROPA PRESS) –
Hypervelocity impact experiments have provided evidence that the intriguing organic matter discovered on Ceres It is indigenous and was probably formed in the presence of water.
One of the most interesting findings from NASA’s Dawn mission is that Ceres, the largest object in the asteroid belt between Mars and Jupiter, hosts complex organic compounds.
The discovery of aliphatic molecules, which consist of carbon and hydrogen chains, together with evidence that Ceres has abundant water ice and may have been an ocean world, means that This dwarf planet could once have housed the main ingredients associated with life as we know it.
How aliphatic organic compounds originated on Ceres has been the subject of intense research since their discovery in 2017. Some studies have concluded that a comet or other impactor rich in organic compounds brought them to Ceres; Others indicate that the molecules formed on the dwarf planet after its primordial materials were altered by salt water. But regardless of its origin, Ceres’ organic matter has been affected by the widespread impacts that have marked its surface.
Now, new research presented in the Geological Society of America GSA Connects 2023 meeting is expanding scientists’ understanding of how impacts have affected Ceres’ aliphatic molecules and what the implications are for determining their origin and assessing the dwarf planet’s habitability.
“The organic compounds were initially detected in the vicinity of a large impact crater, which motivated us to observe how the impacts affect these organic compounds,” says Terik Daly, a planetary scientist at the Johns Hopkins University Applied Physics Laboratory, who led this study. “We are finding that organic compounds may be more widespread than initially reported and that they appear to be resistant to the impacts of Ceres-like conditions.”
From the Dawn data, Daly knew that Ceres is covered in impact craters of varying sizes formed when other asteroids collided with Ceres. But what he did not yet understand was how these impacts affect aliphatic compounds, information that was needed to help determine where the organic compounds originated and how their signatures they could have changed after being exposed to multiple impacts over billions of years.
“Although researchers have performed impact and crash experiments with various types of organic matter in the past,” says Daly, “what was missing was a study dedicated to the type of organic matter detected on Ceres using the same type of analytical method used by the Dawn spacecraft to detect them.” This, she states, would allow direct comparisons between experimental and spacecraft data.
Daly worked with a team that included Jessica Sunshine, an astronomer at the University of Maryland, and Juan Rizos, a postdoctoral researcher at the University of Maryland who is now an astrophysicist at the Institute of Astrophysics of Andalusia, to conduct a series of experiments in the field. Ames vertical shot from NASA. The experiments mimicked impact conditions typical of Cereswith impact velocities ranging between 2 and 6 km/s and impact angles varying between 15 and 90 degrees with respect to the horizontal.
Rizos and Sunshine also performed a new analysis that combined data from two different instruments (the camera and the imaging spectrometer flown on the Dawn spacecraft) and then used an algorithm to extrapolate the composition information from the spectrometer to the highest spatial resolution. of the camera. The results allowed them to investigate organic compounds in greater detail than was previously possible.
“People had analyzed the Dawn camera data and the Dawn spectrometer data separately, but no one else had taken the approach our team used to extrapolate data from one instrument to another, which provided a new advantage in our quest to map and understand the origin of organic matter on Ceres,” says Sunshine.
Taken together, the team’s analyzes point to some potentially interesting results. “By leveraging the strengths of two different data sets collected on Ceres, we have been able to map potentially organic-rich areas on Ceres with higher resolution,” says Rizos. “We can see a very good correlation of organic compounds with older impact units and with other minerals such as carbonates that also indicate the presence of water. While the origin of organic compounds remains poorly understood, “Now we have good evidence that they formed on Ceres and probably in the presence of water.”
“There is the possibility that a large interior reserve of organic matter is found within Ceres,” adds Rizos. “So, from my perspective, “This result increases the astrobiological potential of Ceres.”
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