Mumma’s team is now reanalyzing its data to try to determine why its value is the outlier. For now, I will take the 10 ppbv value as the most likely. It corresponds to a concentration of methane (in molecules per unit volume) that is only 40 millionths of the concentration in Earth’s atmosphere. Nevertheless, even the barest presence of the gas demands an explanation.
Although astronomers detected methane on Titan as early as 1944, it was only the additional discovery of nitrogen 36 years later that generated the immense interest in this cold and distant moon [see “Titan,” by Tobias Owen; Scientific American, February 1982]. Nitrogen is a key constituent of biological molecules such as amino acids and nucleic acids. A body with a nitrogen-methane atmosphere, where the ground-level pressure is one and a half times that of our home planet, may have the right ingredients for molecular precursors of life and, some have speculated, even life itself to form.
Methane plays a central, controlling role in maintaining Titan’s thick nitrogen atmosphere. It is the source of hydrocarbon hazes, which absorb solar infrared radiation and warm the stratosphere by approximately 100 degrees Celsius, and of hydrogen, whose molecular collisions result in a 20-degree warming in the troposphere. If the methane ever ran out, temperatures would drop, nitrogen gas would condense into liquid droplets and the atmosphere would collapse. Titan’s special character would change forever. Its smog and clouds would dissipate. The methane rain that seems to have carved its surface would stop. Lakes, puddles and streams would dry up. And, with its veil lifted, Titan’s stark surface would lay bare and readily accessible to telescopes on Earth. Titan would lose its mystique and turn into just another satellite with thin air.
could it be that methane on Mars and Titan has a biological origin, as on Earth, or does it have another explanation, such as volcanoes or impacts of comets and meteorites? Our understanding of geophysical, chemical and biological processes has helped narrow the field of possible sources on Mars, and many of the same arguments apply to Titan as well.
Split by Sunlight
The first step to answering the question is to determine the rate at which methane must be produced or delivered. That, in turn, depends on how fast the gas is being removed from the atmosphere. At altitudes of 60 kilometers and higher above the Martian surface, solar ultraviolet radiation splits methane molecules apart. Lower in the atmosphere, oxygen atoms and hydroxyl radicals (OH), which form when water molecules are broken apart by ultraviolet photons, oxidize methane. Without being resupplied, methane would gradually disappear from the atmosphere. The “lifetime” of methane—defined as the time it takes for the gas concentration to drop by a factor of the mathematical constant e, or roughly three—is 300 to 600 years, depending on the amount of water vapor, which undergoes seasonal changes, and on the strength of solar radiation, which varies during the solar cycle. On Earth, similar processes give methane a lifetime of about 10 years. On Titan, where solar ultraviolet radiation is much weaker and oxygen-bearing molecules are substantially less abundant, methane can last 10 million to 100 million years (which is still a short time in geologic terms).
Methane’s lifetime on Mars is long enough for winds and diffusion to mix the gas into the atmosphere fairly uniformly. Thus, the observed variations of methane levels over the planet are puzzling. They may be a sign that the gas comes from localized sources or disappears into localized sinks. One possible sink is chemically reactive soil, which could accelerate the loss of methane. If such additional sinks operated, it would take an even larger source to maintain the observed abundance.
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Add CommentWant to see some real closeups of Mars,plus life like critters-take a look at these Italian 100 foot off the surface of Mars- see roots,animals footprints etc: www.msss.com/moc_gallery/e07_e12/full_glf_non_map/e10/e1001841.glf
Reply | Report Abuse | Link to thisToreityerate, I suggest staining the atmosphere with a harmless dye the is sensitive to mehane like a gram stain. Use the dye to contrast and locate the sources of methane and any sinks that may explain where the methane gas is recycled. Different optical filters can visually id the sources of methane once the atmosphee is stained.
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Reply | Report Abuse | Link to thisBrilliant!!! After you have invented such a miracle dye that can stain gases in the atmosphere, maybe you can also invent a method to move the requisite millions of tons of that stuff to Mars.
Surely there are non-biological chemical reactions in the vast sub subsrface of the earth that produce methane. The "primitive" tribes along the Alieutian Ismuth between Alaska and Kamchatka lived along the end of the "Circle of fire"that curved around what is now the southern Berring SEa, and according to their descendents folk songs and myths, they named the semi-circled arewa the Farting Sea becasuse of the smell of the undersea effusians that they tapped by ceramic turbines to "energize their first industrial revolution about 11 Millenia ago at the end of the ice age and before the great Tunguska like explosion of a comet over the Arctic Ocean around the North pole that caused the tsunamis ande earth/ice quakes that emptied the Arctic ocean across the world, much through what is now the Bering Sea, denuding of life much of what is now the outer Aleutian chain of islandsislands and some islands such as St Lawrence --and in the other direction from the North Ple, around Iceland and the Isthmus of Faroe to northern Scotland, washing away in the procesws all the evidence of the world-wide industrtialization that was created at the end of the ice age by relying on ceramic turbines utilizing the methane eruptions from the rings of fire and other undersea volcanic sources of power.
Reply | Report Abuse | Link to thisThe point is that all that volcanic methane had to come from somewhere and although we call manatees "sea cows" there just we not millions of giant sea cows farting throughout the seas whose methane wan in some way sequestered into some subsurface bubble that farted gently until perturbed by an exploding comet and its consequential quakes and shifts of a quarter of the water in the world from the Arctic ocean down across EurASIa, North America and the North Atlantic and North Pacific as well as the Bering Sea that bore the brunt of the floods, equal to those that crossed from the Black and Caspian Seas, etc, cleared out the Dardanelles and flowed over what is now Turkey, across the later "Fertile Crescent" and over Lebanon into the great Valley of Middle Earth that is now the Mediterranian sea befor it carved out the Straits ofr Gibralter, met the floods from the North Atlantic ro inundate Atlantis before rushing across the Atlantic and Carribean Islands, washing away the Isthmusfrom Florida to Cuba and proceeding to cross the Mexican Sea (now the Gulf of Mexico and dumping its debris anong the Texas coast, forming what are now barrier islands off-shore from what it had formed as the Great South Texas Salt Sea, now almost all evaporated and covered and covered bysands liberated by winds over THE Continental Shelf and circled by the cedars of Lebanon brought across the Mediterranian Sea and Atlantic Ocean, and growing as if they had been natives around the last of the 4lakes left over from the Great South Texas Salt Sea whose salt was left by evaporation under the South Texas sun as a layer about a foot thick under the sandy soil about 25 feet down.
Surely there are non-biological chemical reactions in the vast sub subsrface of the earth that produce methane. The "primitive" tribes along the Alieutian Ismuth between Alaska and Kamchatka lived along the end of the "Circle of fire"that curved around what is now the southern Berring SEa, and according to their descendents folk songs and myths, they named the semi-circled arewa the Farting Sea becasuse of the smell of the undersea effusians that they tapped by ceramic turbines to "energize their first industrial revolution about 11 Millenia ago at the end of the ice age and before the great Tunguska like explosion of a comet over the Arctic Ocean around the North pole that caused the tsunamis ande earth/ice quakes that emptied the Arctic ocean across the world, much through what is now the Bering Sea, denuding of life much of what is now the outer Aleutian chain of islandsislands and some islands such as St Lawrence --and in the other direction from the North Ple, around Iceland and the Isthmus of Faroe to northern Scotland, washing away in the procesws all the evidence of the world-wide industrtialization that was created at the end of the ice age by relying on ceramic turbines utilizing the methane eruptions from the rings of fire and other undersea volcanic sources of power.
Reply | Report Abuse | Link to thisThe point is that all that volcanic methane had to come from somewhere and although we call manatees "sea cows" there just we not millions of giant sea cows farting throughout the seas whose methane wan in some way sequestered into some subsurface bubble that farted gently until perturbed by an exploding comet and its consequential quakes and shifts of a quarter of the water in the world from the Arctic ocean down across EurASIa, North America and the North Atlantic and North Pacific as well as the Bering Sea that bore the brunt of the floods, equal to those that crossed from the Black and Caspian Seas, etc, cleared out the Dardanelles and flowed over what is now Turkey, across the later "Fertile Crescent" and over Lebanon into the great Valley of Middle Earth that is now the Mediterranian sea befor it carved out the Straits ofr Gibralter, met the floods from the North Atlantic ro inundate Atlantis before rushing across the Atlantic and Carribean Islands, washing away the Isthmusfrom Florida to Cuba and proceeding to cross the Mexican Sea (now the Gulf of Mexico and dumping its debris anong the Texas coast, forming what are now barrier islands off-shore from what it had formed as the Great South Texas Salt Sea, now almost all evaporated and covered and covered bysands liberated by winds over THE Continental Shelf and circled by the cedars of Lebanon brought across the Mediterranian Sea and Atlantic Ocean, and growing as if they had been natives around the last of the 4lakes left over from the Great South Texas Salt Sea whose salt was left by evaporation under the South Texas sun as a layer about a foot thick under the sandy soil about 25 feet down.
Sorry, I want to see them but can't see them; the link don't work!
Reply | Report Abuse | Link to thisSorry for my duplicate posts above but I didn't think it had posted because it said my log on had failed. If there is a way to delete the duplicate, please let me know.