Hydrocarbons in comets or asteroids likely were formed like those on Earth – biogenically, according to AAPG member Prasanta K. Mukhopadhyay.
Yes, you read that correctly: "biogenically," as in, "arising from life" – in this case, extraterrestrial life.
Mukhopadhyay likens meteorites known as carbonaceous chondrites (CCs) to "cosmic dandelions," spreading hydrocarbons and life-forming elements throughout the solar system.
Oil and gas hydrocarbons found on planets and moons may come from comets or asteroids and share biogenic and maturation signatures with Earth source rocks, Mukhopadhyay said.
"From the standpoint of the presence of hydrocarbons and PAHs (polycyclic aromatic hydrocarbons), I believe that both life and hydrocarbons could be universally connected," Mukhopadhyay said.
Further, he said the solar system's unconventional petroleum system could eventually provide fuel for space travelers and interplanetary colonists.
"Part of my concept is that thermal degradation nannobacteria and other archaeoprokaryotic organisms, related hydrocarbons and other molecules in the CCs derived from the comets or asteroids may be cosmic ‘dandelions,'" he said, "preserving, growing and distributing hydrocarbons and life-forming ingredients through soft landing of meteorite showers and purging as comet dust in the solar system."
Mukhopadhyay, a Halifax, Canada based organic petrologist and organic geochemist, said his research and that of others suggests these CCs, or meteorites, were derived from asteroids, comets or the planet Mars.
"Since 2004, I have conducted some comprehensive research on more than 20 carbonaceous meteorites (CCs, or carbonaceous chondrites) using organic petrology (using transmitted and incident light microscope), organic geochemistry (organic carbon analyzer, Rock-Eval pyrolysis and pyrolysis gas chromatography-mass spectrometry), scanning electron microscope and SEMEDS (SEM with energy dispersive X-ray spectrometer), sometimes in association with other scientists from Mount Allison University, New Brunswick, Canada," he explained.
"My data suggested that these CCs are all organic-rich and contain abundant macromolecular components," he said, "and biomarkers similar to kerogen and bitumen occur within petroleum source rocks as we have seen in the terrestrial source rocks that have generated oil and gas. Remarkable bacteriomorphic structures and other kerogenous microstructures preserved in CCs closely resemble remnant terrestrial palynomorphs of microbial (prokaryotic and archaeoprokaryotic) ecosystems established on Earth over 3.5 billion years ago.
"All CCs that were examined contain solid, bitumen-like components," he said. "My data corroborates the earlier concept by astrobiologists that (certain) meteorites contain fossil cyanobacteria, extraterrestrial l-amino acids, nucleobases and water," he added. "Similarly, various publications (e.g. Geochimica et Cosmochimica Acta) by various geochemists and astrogeologists also support my idea on the organic origin of these hydrocarbonlike components in the CCs over the last 20 years.
"Recent data by the European Space Agency's Rosetta Probe that landed on Comet 67P/Churyumov-Gerasimenko may also support the presence of hydrocarbons on that comet," he said.
New Corroborating Data Rosetta's Philae lander recently "reawakened," and Mukhopadhyay said he is excited by the potential findings in the data that may be returned.
"They found as the comet goes toward the sun, when facing the sun, it ejects gases and hydrocarbons," he said. "That's exactly that what my concept is. "In effect, the information encoded in the CCs constitutes a cosmic analog to terrestrial geopolymers or macerals in organic-rich source rocks (kerogen type II) and their derivative liquid and/or solid hydrocarbons," he continued.
This, he said, may raise these questions:
♦ Is oil and gas within our solar system mostly biologically derived (possibly from the thermal degradation of nanobacteria and other archaeoprokaryotic organisms)?
♦ Is there a close relationship between the origin of early biota and universality of the presence of unconventional oil and gas within various planets in our solar system?" Mukhopadhyay discussed his findings in a presentation at this year's AAPG Annual Conference and Exhibition (ACE) in Denver, and he is preparing a related presentation for an upcoming conference for SPIE, the International Society for Optics and Photonics.
The geochemist has been studying CCs for years, and in a 2009 paper he and his co-authors suggested a "biologically-derived, universal, unconventional petroleum system throughout the solar system."
"My concept could be validated if any core drilling data on Comet 67P/ Churyumov-Gerasimenko or on Mars is available in the future," he said. "However, my organic petrology, SEM-EDS and geochemical data (especially pyrolysis GC/MS of Murchison, Orgueil and Tagish Lake CCs) clearly indicated the organic origin of these carbonaceous chondrites (meteorites) as they contain bacteriallyderived hydrocarbon species."
He said his study and modeling of CCs indicate two temperature-influenced categories of organic compounds:
♦ Low temperature – less than 200 C degrees – acted on organic remains to form oil, gas and some asphaltene.
Geochemically, the CCs are "remarkably close" to oil-prone kerogen type II and II-III source rocks found on Earth, he said.
He proposes they were formed in relatively cold and humid areas of the early solar system, comets and interstellar dust "where microbial-like and slightly evolved organic communities could have developed."
He said it is not surprising that comets and CCs contain key life-forming elements like hydrogen, oxygen, carbon and sulfur.
♦ High temperature organic remnants were found in some of the CCs he studied. He likened the extreme superheated environment to that around hydrothermal vents in earth's oceans.
In his 2009 paper, he stated, "Even in such an extreme environment, biological life and hydrocarbon generation are intimately linked."
What Does It All Mean?
Some readers – particularly science fiction fans – might recognize Mukhopadhyay's concept as "panspermia" – the idea that life originated elsewhere and was "seeded" on Earth as microbes that evolved into the more complex forms that populate the planet today.
There is, of course, a range of connotations evoked with that word.
"Directed panspermia" was the premise of the 2012 Ridley Scott-directed movie "Prometheus," which featured an advanced alien race having deliberately planted life on Earth to give rise to the human race.
While directed panspermia was advanced by no less than the Nobel Prize-winning co-discoverer of DNA, Francis Crick, Mukhopadhyay's hypothesis isn't quite so extreme. His concept is more aligned with the "soft" variety of panspermia: That it was natural processes, not ancient alien scientists, responsible for life arriving on Earth.
Of course, his concept still necessarily includes the existence of extraterrestrial life, which inevitably raises some eyebrows.
"It could be coincidental and surprising that these materials have a similar composition of the terrestrial source rocks that originated from various palynomorphs. Therefore, I do not have any alternative explanation," he said.
He said the idea of extraterrestrial biogenic hydrocarbons drew opposition early on, but has garnered growing support, especially since about 2009.
He said his geochemical work indicates certain CCs found in South Africa and Australia basically contain 3.8 billion year old source rock.
"There is hydrocarbon-type material there – I'm not saying life," he said.
He said research points to life and hydrocarbons originating very close together in the early universe.
"Life is universal," he said.
If Mukhopadhyay and the others are correct, it would obviously have far-reaching philosophical and religious implications about man's place in the universe, but Mukhopadhyay said that shouldn't be a factor in considering his hypothesis.
"I believe that any scientists conducting space research should be honest and candid in his/her research findings and should not be biased with any preconceived notions, ideas or religious beliefs. Space science could be an ocean of new knowledge that could open up a new dimension of human knowledge," he said.
"I'm a geochemist – when life began is not my business," he said. "My business is how the hydrocarbons formed."