2024-08-21 08:15:25
Since the first detection of molecules in space more than a century ago, there is great interest in finding out how molecules are formed in space and, in particular, prebiotic molecules, which are ingredients for the emergence of life.
The team of Kennedy Barnes, Rong Wu, Christopher Aruminayagam and James Battat, four from Wellesley College, in the United States, set out to explore the relative importance of low-energy electrons versus photons for chemical reactions responsible for the synthesis of those prebiotic molecules in space .
In the few studies that have previously sought to answer this question, it has been concluded that both electrons and photons can catalyze the same reactions. However, the study by Barnes and his colleagues shows that the prebiotic molecule obtained from low-energy electrons and photons can be significantly different in space. “Our calculations suggest that the number of electrons induced by cosmic rays within the cosmic ice may be much greater than the number of photons hitting the ice,” explains Barnes. “Therefore, electrons probably play a more important role than photons in the extraterrestrial synthesis of prebiotic molecules.”
When trying to better understand the synthesis of prebiotic molecules, researchers did not limit their efforts to mathematical modeling; They also tested their hypothesis by simulating spatial conditions in the laboratory. They use a vacuum chamber containing an ultra-pure copper substrate that they can cool to ultra-low temperatures, as well as an electron gun that produces low-energy electrons and a laser-powered plasma lamp that produces low-energy photons. scientists bombard nanoscale ice films with electrons or photons to see what molecules are produced.
Researchers simulate the conditions of interstellar space with this ultra-high-vacuum, low-temperature chamber containing an electron source to recreate the formation of life-critical substances in space. (Photo: Kennedy Barnes)
“Although we have previously focused on how this research relates to submicron interstellar ice particles, it is also relevant to cosmic ice on a much larger scale, such as Jupiter’s moon Europa, which has a 32 kilometer ice shell It has thickness,” Barnes explains.
Therefore, he suggests that his research will help astronomers better understand some of the data found in observations made by space telescopes such as the James Webb, as well as some of the data obtained by the Europa Clipper space probe, which is about to be launched. first in October 2024. . Barnes hopes his findings will encourage other researchers to incorporate low-energy electrons into their astrochemistry models to simulate what happens inside cosmic ice.
This study was presented publicly at a recent ACS (American Chemical Society) meeting.
Barnes and his colleagues are also modifying the molecular composition of the ice films and exploring atom addition reactions to test whether low-energy electrons can produce other probiotic chemicals. This work is carried out in collaboration with researchers from the Laboratory for the Study of Radiation and Matter in Astrophysics and Atmospherics in France. (Source: ACS)
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