Comet 67P/Churyumov-Gerasimenko is much richer in complex organic molecules than scientists expected, and until now some of these molecules had never been seen around a comet.
Because comets are believed to be responsible for seeding complex carbon-based molecules essential to life on Earththe findings could have implications for how life originated on our planet.
The team, made up of scientists from the University of Bern in Switzerland, conducted their research using data collected by the Rosetta spacecraft and analyzed by its mass spectrometer, ROSINA, between 2014 and 2016. Rosetta and its lander Philae, which landed on the comet, arrived on Comet 67P/Churyumov-Gerasimenko (or Chury, as scientists call it) in 2014 before Rosetta completed her mission with an intentional plunge into the comet two years later.
Related: See all comet photos (and more) from the European Rosetta probe
From this data, the researchers identified for the first time a series of complex organic molecules on a comet, revealing what the team calls the comet’s “organic budget”. The research also extends to the types of molecules that could have been delivered by comets.
“It turned out that, on average, the complex organic balance of Chury is identical to the soluble part of meteoritic organic matter,” said Nora Hänni, postdoctoral researcher at the University’s Department of Space Research and Planetary Sciences. from Bern. statement (opens in a new tab). “It therefore seems likely that the impact of comets – as essential providers of organic matter – also contributed to the emergence of carbon-based life on Earth.”
Chury’s molecular budget is similar to the organic matter raining down on Saturn of its innermost ring, as detected by a NASA onboard mass spectrometer Cassini spacecraftHanni added.
Rosetta has made further analysis of the chemical content of Chury and its larger molecules thanks to a phenomenon that occurs when comets pass near the Sun when the ice it contains begins to melt and burst from its surface.
When Chury reached the point in its orbit closest to our star, the comet became active. The ices sealed inside the comet were immediately transformed from solids to gases – a process called sublimation – and released from the surface in a flow. This jet of gas dragged dust molecules from the surface with it.
These particles were then heated by radiation from the sun to temperatures much hotter than those experienced by particles on the surface of the comet. This means that larger molecules are released or “desorbed” from the dust, making them available for detection and analysis by ROSINA.
What Comet Chury Looks Like
ROSINA’s analysis revealed types of chemicals composed of many atoms, including complex organic molecules and molecules never detected in any comet before, which were previously hidden in the dust of the comet.
Among these were the traces of certain compounds on Earth that help form familiar scents.
“We found, for example, naphthalene, which is responsible for the characteristic smell of mothballs,” Hänni said. “And we also found benzoic acid, a natural component of frankincense,” says Hänni. “In addition, we identified benzaldehyde, widely used to impart almond flavor to foods, and many other molecules.
“These heavy organics would apparently make Chury’s scent even more complex, but also more appealing.”
Some of the other molecules, like formamide, have what’s called prebiotic functionality, meaning they help in the synthesis of biomolecules like amino acids and sugars.
The team placed Chury’s organic budget in the broader context of the solar system and even the clouds of gas and dust collapsing to form new stars and planetary systems. It helped substantiate what scientists had suspected for some time about comets like Chury: that they are potential “fossil records” of the material that formed the planets of the solar system 4.5 billion years ago. years.
“We not only find similarities in the organic reservoirs of the solar system, but many of the organic molecules of Chury are also present in molecular clouds, the cradles of new stars,” said Susanne Wampfler, an astrophysicist at the Center for Science. space and habitability of the University of Bern, said in the statement. “Our findings are consistent with and support the scenario of a shared presolar origin of the Solar System’s various pools of organic matter, confirming that comets are indeed transporting material long before our Solar System emerged.”
The team’s research was published in June in the journal Nature (opens in a new tab).
Follow us on twitter @Spacedotcom and on Facebook.
#Comet #67P #building #blocks #life #smells #mothballs #almonds