Tag Archives: methane

Scientists resolve one Mars methane mystery

Scientists have now figured out why the methane data from Curiosity on the Martian surface did not match the methane data from Trace Gas Orbiter in orbit around Mars.

Last year, scientists learned that methane concentrations changed over the course of the seasons with a repeatable annual cycle. “This most recent work suggests that the methane concentration changes over the course of each day,” Dr Moores said. “We were able – for the first time – to calculate a single number for the rate of seepage of methane at Gale crater on Mars that is equivalent to an average of 2.8 kg per Martian day.”

Dr Moores said the team was able to reconcile the data from the ExoMars Trace Gas Orbiter and the Curiosity Rover, which appeared to contradict each other with wildly different detections of methane. “We were able to resolve these differences by showing how concentrations of methane were much lower in the atmosphere during the day and significantly higher near the planet’s surface at night, as heat transfer lessens,” he said.

Solving that data conflict helps them get a better grip on the real question: Why is the methane fluctuating in this manner?

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Spike in methane detection in Gale Crater

The uncertainty of science: In the past week Curiosity has suddenly discovered a spike, the largest ever, in the amount of methane in the local atmosphere.

The amount detected was still quite tiny, 21 parts per billion by volume.

Curiosity doesn’t have instruments that can definitively say what the source of the methane is, or even if it’s coming from a local source within Gale Crater or elsewhere on the planet.

“With our current measurements, we have no way of telling if the methane source is biology or geology, or even ancient or modern,” said SAM Principal Investigator Paul Mahaffy of NASA’s Goddard Spaceflight Center in Greenbelt, Maryland.

While there is going to be a lot of speculation in the press and among scientists who should know better, this detection remains a major mystery. We as yet have no idea what caused it. Nor is it likely to have been caused by biology, though that does remain a possibility.

What is most puzzling is that the terrain that Curiosity is presently traveling across, the clay unit at the foot of Mount Sharp, shows no likely source.

This past weekend the scientists focused the rover’s instruments on this topic, in the hope this could help narrow the problem.

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Mars Express confirms Curiosity 2013 methane detection

The uncertainty of science: The Mars Express science team today announced that a reanalysis of the orbiter’s data showed the same spike spike of methane detection as seen by Curiosity on June 15, 2013.

The study exploited a new observation technique, allowing the collection of several hundred measurements in one area over a short period of time. The teams also developed a refined analysis technique to get the best out of their data.

“In general we did not detect any methane, aside from one definite detection of about 15 parts per billion by volume of methane in the atmosphere, which turned out to be a day after Curiosity reported a spike of about six parts per billion,” says Marco Giuranna from the Institute for Space Astrophysics and Planetology in Rome, Italy, the principal investigator for the PFS experiment, and lead author of the paper reporting the results in Nature Geoscience today.

“Although parts per billion in general means a relatively small amount, it is quite remarkable for Mars – our measurement corresponds to an average of about 46 tonnes of methane that was present in the area of 49 000 square kilometres observed from our orbit.”

Ten other observations in the Mars Express study period that reported no detections at the limit of the spectrometer’s sensitivity corresponded to a period of low measurements reported by Curiosity.

The data, along with their estimate about the source location for the methane, suggests that this was a geological event, not the result of biological life. They think the methane was trapped in ice-filled fissures, and released when that ice either broke or melted. Whether the methane itself was formed by past microbial life sometime in the past remains completely unknown.

To put it mildly, there are a lot of uncertainties in this result.

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Trace Gas Orbiter finds no methane on Mars

The uncertainty of science: Europe’s Trace Gas Orbiter (TGO) has failed to detect any methane in Mars’ atmosphere, even though data from Mars Express in 2004 had said it should see some.

The Mars Express orbiter first detected hints of methane in the martian atmosphere in 2004. But some scientists said the orbiter’s instruments that found it—at a level of 10 parts per billion (ppb)—weren’t sensitive enough to produce reliable results. Ten years later, NASA’s Curiosity rover detected a methane spike of 7 ppb from its base in Gale crater, which lasted several months. Several years later, Curiosity’s scientists then discovered a minute seasonal cycle, with methane levels peaking at 0.7 ppb in the late northern summer.

To settle this mystery, the European Space Agency’s Trace Gas Orbiter (TGO), which arrived at Mars in 2016, this year began to scan the atmosphere for methane. Two of the TGO’s spectrometers—a Belgian instrument called NOMAD and a Russian one called ACS—were designed to detect methane in such low concentrations that researchers were sure they would. Both instruments, which analyze horizontal slices of the martian atmosphere backlit by the sun, are working well, scientists on the team said today at a semiannual meeting of the American Geophysical Union in Washington, D.C. There’s still some noise to clean up, said Ann Carine Vandaele, NOMAD’s principal investigator and a planetary scientist at the Royal Belgian Institute for Space Aeronomy in Brussels, in her talk. “But we already know we can’t see any methane.”

The team’s initial results show no detection of methane down to a minute level of 50 parts per trillion, with their observations going down nearly all the way to the martian surface.

The data says that any methane seen on the surface (such as by Curiosity) must be coming from below, not from off world, which in itself is a surprise since the scientists expected some methane to be coming from interplanetary dust. TGO has found none..

There are a lot of uncertainties still, so stay tuned.

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Scientists calculate Mars methane release

A new model describing how warmer weather could cause the seasonal spikes of methane on Mars matches the data from Curiosity in Gale Crater.

Moores and his colleagues analysed how methane might seep upwards through cracks and fissures in the Martian soil until it enters the atmosphere. Warming the soil could allow the gas to leak into the air, their calculations show. Seasons on Mars are complex, especially at Curiosity’s location so close to the planet’s equator. But the highest methane levels do appear just after the warmest time of the year, suggesting that heat spreading downward allows more of the gas to be released.

The amount of gas that the scientists estimate is entering the atmosphere is a good match for the measurements Curiosity has made at Gale crater, Moores told the American Astronomical Society’s Division for Planetary Sciences meeting in Knoxville, Tennessee. The methane’s ultimate source is still a mystery. But the work could help to explain the gas’s seasonal ebb and flow, he said. [emphasis mine]

The highlighted sentence is the most important. All they have done is found that they can model the pattern of seasonal release. They still have no idea whether the methane comes from a geological or biological source, which is of course the real question.

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Curiosity finds methane fluctuates seasonally in Gale Crater

Seasonal methane on Mars

In its second significant science release yesterday (the first relating to the discovery of organics), the Curiosity science team revealed that they have found over almost three Martian years the amount of methane in the atmosphere appears to fluctuate seasonally. The graph on the right illustrates this change.

[The data] show methane rises from just above 0.2ppb in the northern hemisphere winter to a fraction over 0.6ppb in the summer. The team’s best explanation is that methane is seeping up from underground, perhaps from stored ices, and is then being released when surface soils are warmed.

The team cannot positively identify the origin of the methane, but the researchers think they can close down one particular mechanism for its production. This involves sunlight breaking up carbon-rich (organic) molecules that have fallen to the planet’s surface in meteorites.

The variation in ultraviolet light over the course of the seasons is not big enough to drive the scale of the change seen in the methane concentration, says Dr Webster. “We know the intensity of the Sun and this mechanism should produce only a 20% increase in methane during the summer, but we’re seeing it increase by a factor of three,” he explained.

The change could be caused by either a chemical or a biological process. At this time there is no way to determine which.

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A faint seasonal fluctuation of methane on Mars?

The uncertainty of science: Data from Curiosity during its two Martian years on Mars have revealed a faint but distinct seasonal fluctuation in the amount of methane in the local atmosphere, a fluctuation that scientists do not have a good explanation for.

Since landing in 2012, Curiosity has on 30 occasions opened a few valves to the martian night and taken a sniff of the thin, frigid air. In a small, mirrored chamber, it shines a laser through the air sample and measures the absorption at specific wavelengths that indicate methane. At the meeting, Webster reported vanishingly small background levels of the gas: 0.4 parts per billion (ppb), compared with Earth’s 1800 ppb.

Where that whiff comes from is the heart of the mystery. Microbes (including those that live in the guts of cows and sheep) are responsible for most of Earth’s methane, and Mars’s could conceivably come from microbes as well—either contemporary microbes or ancient ones, if the methane they produced was trapped underground. But methane can also be made in ways that have nothing to do with biology. Hydrothermal reactions with olivine-rich rocks underground can generate it, as can reactions driven by ultraviolet (UV) light striking the carbon-containing meteoroids and dust that constantly rain down on the planet from space.

Now, add to the methane puzzle the seasonal variation Curiosity has detected, with levels cycling between about 0.3 ppb and 0.7 ppb over more than two martian years. Some seasonality is expected in an atmosphere that is mostly carbon dioxide (CO2), says François Forget, who models the climate of Mars at the Laboratory of Dynamical Meteorology in Paris. In the southern winter, some of that CO2 freezes out onto the large southern polar cap, making the overall atmosphere thinner. That boosts the concentration of any residual methane, which doesn’t freeze, and by the end of northern summer this methane-enriched air makes its way north to Curiosity’s location, Forget says. Seasonal variations in dust storms and levels of UV light could also affect the abundance of methane, if interplanetary dust is its primary source.

But, Webster said at the meeting, the seasonal signal is some three times larger than those mechanisms could explain. Maybe the methane—whatever its source—is absorbed and released from pores in surface rocks at rates that depend on temperature, he said. Another explanation, “one that no one talks about but is in the back of everyone’s mind,” is biological activity, says Mike Mumma, a planetary scientist at Goddard Space Flight Center in Greenbelt, Maryland. “You’d expect life to be seasonal.”

They have a lot of theories, from asteroids to alien life, but none really explains this adequately.

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New study finds fracking does not contaminate drinking water

The uncertainty of science: A new study, using data from more than 11,000 drinking water wells in northern Pennsylvania, has found no evidence that fracking causes contamination.

The new study of 11,309 drinking water wells in northeastern Pennsylvania concludes that background levels of methane in the water are unrelated to the location of hundreds of oil and gas wells that tap hydraulically fractured, or fracked, rock formations. The finding suggests that fracking operations are not significantly contributing to the leakage of methane from deep rock formations, where oil and gas are extracted, up to the shallower aquifers where well water is drawn.

The result also calls into question prominent studies in 2011 and 2013 that did find a correlation in a nearby part of Pennsylvania. There, wells closer to fracking sites had higher levels of methane. Those studies, however, were based on just 60 and 141 domestic well samples, respectively.

The article outlines in detail the many disagreements and uncertainties of both the old studies and this new one. It also however contains this one key quote about the earlier studies, buried in the text, that illustrates the politics influencing the reporting of the anti-fracking research:

The two papers seemed to show that fracking was leading to increased concentrations of methane in drinking water. Dissolved methane is not toxic, and drinking water often contains significant background levels of the gas from natural sources. [emphasis mine]

The earlier studies were blasted everywhere by the media. They were used to show the harm fracking does, and were the justification for the banning of fracking in New York. Yet, the methane they found was not necessarily caused by fracking, and isn’t even a health concern anyway.

I wonder if the press will give this new report as much coverage. It might not be right, but it sure does indicate that the science is unsettled, and that the risks from fracking are, as usual in these days of doom-saying environmentalism, overblown.

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Methane does exist in the Martian atmosphere

The uncertainty of science: Curiosity has confirmed the presence, and fluctuation, of methane in the local Martian atmosphere.

SAM [Sample Analysis at Mars, one of Curiosity’s instruments] has been detecting basal levels of methane concentration of around 0,7 ppbv, and has confirmed an event of episodic increase of up to ten times this value during a period of sixty soles (Martian days), i.e., of about 7 ppvb. The new data are based on observations during almost one Martian year (almost two Earth years), included in the initial prediction for the duration of the mission (nominal mission), during which Curiosity has surveyed about 8 kms in the basin of the Gale crater.

Since methane has a short life expectancy, something must be doing something to generate it.

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Methane leaks from natural gas wells less than predicted

Once again, Chicken Little was wrong! A new study has found that methane leaks from modern natural gas exploration is far lower than expected.

Essentially, the usual environmental doom-sayers had claimed that methane leaks would be 50% higher than predicted by industry experts. Instead, they are lower than expected, and likely pose no risk to the environment.

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The seas of Titan

Thar’s black gold up thar! Data from Cassini has confirmed the presence of ocean waves on Titan’s seas, while also providing suggesting that they are made mostly of liquid methane, not ethane as had been predicted.

The maximum depth of Kraken Mare appears to be 160 meters, and Ligeia Mare could be as much as 200 meters deep, reported Marco Mastrogiuseppe of Sapienza University of Rome. The fact that the radar signals could bounce off the sea bottom suggests that the seas were more transparent than expected and thus must contain mostly methane, not ethane. Hayes says his best estimate is about 90% methane. Essam Marouf, a planetary scientist at San José State University in California, reported on the first results from a separate radar experiment that sent radar reflections to Earth instead of back to the spacecraft. Those tests provide independent evidence that the seas are dominated by methane, Marouf says, and it implies that the lakes are kept filled by precipitating methane.

As the article also notes, this methane is “55 times Earth’s oil reserves.”

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Curiosity finds organic materials on Mars, including fluctuating levels of methane

Data from Curiosity has found both organic chemicals in the surface of Mars as well as quickly changing levels of methane in the nearby atmosphere.

NASA’s Mars Curiosity rover has measured a tenfold spike in methane, an organic chemical, in the atmosphere around it and detected other organic molecules in a rock-powder sample collected by the robotic laboratory’s drill. “This temporary increase in methane — sharply up and then back down — tells us there must be some relatively localized source,” said Sushil Atreya of the University of Michigan, Ann Arbor, and Curiosity rover science team. “There are many possible sources, biological or non-biological, such as interaction of water and rock.”

The organic material does not prove there is or was ever life on Mars. What it shows is that conditions on Mars could have once supported life. The methane detection, however, is a more significant finding, as it suggests that something very nearby to Curiosity is causing the spike. It could be life, or it could be chemical activity, but in either case, it means there is activity.

The one caveat is that the spike still did not amount to much, 7 parts per billion. Whatever is causing it is not really doing very much.

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Natural methane plumes found on the sea floor

The uncertainty of science: Scientists have discovered hundreds of natural methane sea-floor seeps that had not been predicted by theory.

The bubble streams showed up on sonar scans of the sea floor taken between September 2011 and August 2013 during oceanographic expeditions ranging from Cape Hatteras in North Carolina to Georges Bank off Cape Cod. Altogether, researchers analysed data covering a 94,000-square-kilometre arc (an area about the size of Indiana or Hungary) that includes the edge of the continental shelf and the steep slope just seaward of it, says co-author Adam Skarke, a geologist at Mississippi State University in Starkville. Within a distance of about 950 kilometres, the team found about 570 bubble plumes — an astounding number considering that scientists had previously reported only a handful in the region, he notes.

The article’s first two paragraphs breathlessly attempt to link these plumes to human-caused global warming, noting that there is theory that a warming ocean could produce such methane seeps. Worse, the article adds, once this methane is released it will accentuate warming, as methane is a very powerful greenhouse gas.

The article’s last paragraph, however, finally tells us the real story. Hard data gathered by remote robot vehicles that have actually visited these kinds of plumes instead suggests that the plumes have been there for more than a thousand years and thus could have nothing to do with human-caused global warming. In fact, their natural existence is a significant problem for most climate theories, as they now have to account for this additional greenhouse gas, naturally produced.

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Despite data from orbiting probes that say there is methane in Mars’ atmosphere, Curiosity has detected none.

Despite data from orbiting probes that say there is methane in Mars’ atmosphere, Curiosity has detected none.

The detection of methane by orbiting satellites in certain regions of Mars was intriguing as it suggested the possibility of Martian microbiological life. Curiosity is not in those regions, but apparently the scientists thought they’d detect evidence of it from a distance. That they did not reduces significantly the possibility of life on Mars.

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Scientists now think it is possible for there to be floating methane ice on the lakes of Titan.

Scientists now think it is possible for there to be floating methane ice on the lakes of Titan.

Up to this point, Cassini scientists assumed that Titan lakes would not have floating ice, because solid methane is denser than liquid methane and would sink. But the new model considers the interaction between the lakes and the atmosphere, resulting in different mixtures of compositions, pockets of nitrogen gas, and changes in temperature. The result, scientists found, is that winter ice will float in Titan’s methane-and-ethane-rich lakes and seas if the temperature is below the freezing point of methane — minus 297 degrees Fahrenheit (90.4 kelvins). The scientists realized all the varieties of ice they considered would float if they were composed of at least 5 percent “air,” which is an average composition for young sea ice on Earth. (“Air” on Titan has significantly more nitrogen than Earth air and almost no oxygen.)

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Not only have the models failed to predict temperature, they also have failed to predict the amount of methane in the atmosphere.

Another IPCC failure, revealed in the leaked report: Not only have the models failed to predict global temperature, they also have failed to predict the amount of methane in the atmosphere.

The graph at the link is just like the temperature graph I posted on Monday. It compares actual observations with the predictions of the computer models, which all called for a hefty rise in atmospheric methane. All the models got it wrong.

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A Russian scientist has found large amounts of methane being released in the atmosphere in the Arctic

A Russian scientist has found large amounts of methane being released into the atmosphere in the Arctic, far more than previously predicted.

It is speculated that these releases are the result of the Earth’s warming climate during the past several hundred years. And because methane is a far more powerful greenhouse gas than carbon dioxide, its release will feed into that warming.

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Ethane lakes in a red haze: Titan’s uncanny moonscape

Titan’s ethane lakes in a red haze.

So far, there are no recognisable signs of organic life. That’s not surprising: by terrestrial standards, Titan is a deep freeze with surface temperatures at a chilly -180°C. Yet Titan is very much alive in the sense that its atmosphere and surface are changing before our eyes. Clouds drift through the haze and rain falls from them to erode stream-like channels draining into shallow lakes. Vast dune fields that look as if they were lifted from the Sahara sprawl along Titan’s equator, yet the dark grains resemble ground asphalt rather than sand. It is a bizarrely different world that looks eerily like home. Or as planetary scientist Ralph Lorenz puts it: “our prototype weird-world exoplanet”.

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