NASA/Theophilus Britt Griswold
Comets may have played a crucial role in water supply – and possibly some of the molecular ingredients for life – to our planet.
A new investigation revealed convincing evidence that the a comet water is very similar to that found in the oceans of the earthoffering new support to the idea that comets may have played a crucial role in water supply – and possibly some of the molecular ingredients for life – to our planet.
Using the powerful Soul (Atacama Large Millimeter/Submillimeter Array), an international team of scientists led by Martin Cordiner of NASA’s Goddard Space Flight Center, mapped to distribution Both common water (H2O) how much “heavy” water (HDO, which contains the heaviest isotope, deuterium) in the hair (the cloud of gas surrounding the nucleus) of the Halley Comet, 12p/Pons-Brooks, during its approach to the sun.
This is the first time there has been such a detailed space mapping of these two forms of water in a comet.
Alma’s observations were then combined with data on water and other gases, observed using NASA’s Infrared Telescope (IRTF) to form a more complete image of the comet.
By combining the complementary capabilities of these two telescopes, the researchers managed to measure the proportion of deuterium for hydrogen (D/h) in the comet water, a Chemical Digital Impression which helps scientists track the origins and history of water throughout the solar system.
Surprisingly, The D/H proportion of the comet 12p/pons-brooks was considered virtually indistinguishable from that of the earth’s oceans.
The measurement, (1.71 ± 0.44) × 10−4, is the smallest ratio already measured in a shallley comet and is at the lower end of the values observed before in other comets.
“Comets like this are frozen relics that have left the birth of our solar system 4.5 billion years ago,” Cordiner.
“It is thought that the earth has formed from materials without water, so it has long been suggested that the Comet impacts were the source of the earth’s water. Our new results provide the strongest evidence so far that at least some comets type-halley transported water with the same isotopic signature found on Earthsupporting the idea that Comets may have helped make our planet habitable“.
Halley-type comets are a class of comets with intermediate orbital periods (between 20 and 200 years) and visit the inner solar system only rarely.
The conclusions of are significant because previous measurements in other comets often showed water with a different D/H proportion from that of the earth, leaving in doubt the cometian origin of the earth’s water.
This new measurement suggests that some comets -particularly those like 12p/pons-brooks-could indeed have Transported water, and possibly other elements essential to life, to a young land.
The investigation also confirms the origin of the gases observed, providing a more accurate image of the true composition of the comet.
“By mapping both H2O and HDO in the comet’s hair, we can tell if these gases come from the gells within the solid body of the nucleus, rather than forming from chemical processes or other processes in the gaseous hair,” said Stefanie Milam of NASA, co -author of the study.
The observations were only possible thanks to the exceptional sensitivity and unique image capabilities of the soul, which allowed the team to detect the weak signing of heavy water emanating from the most internal regions of the hair – something that had never been mapped before a comet.
