NASA's Mars rover, Curiosity, has detected the largest amount of methane yet measured during its seven years on the Red Planet. It's a particularly riveting discovery because the methane levels discovered by the rover are about three times higher than previous detections, leading to some speculation the gas may be biological in origin.

A report by the New York Times on Saturday first revealed the curious finding after obtaining an internal email from Ashwin Vasavada, a project scientist on the mission. On Sunday, NASA released a statement confirming the discovery, explaining how Curiosity's Sample Analysis at Mars (SAM) suite of instruments had detected methane at 21 parts per billion units by volume -- much higher than ever before.

Methane is an important molecule for microbes on Earth and its detection on another planet has led to speculation that tiny microbes are (or were) puffing gas out at such a rate that NASA's intrepid rover can spot them.

Scientists have detected hints of methane on the surface of Mars in the past, including as far back as the Viking missions in the 1970s. Thus, the discovery of more methane doesn't necessarily mean we've stumbled upon life. Spikes in Mars' methane levels aren't unusual, with a study reporting last June on seasonal variations in the molecule's atmospheric concentration.

Thomas Zurbuchen, associate administrator of NASA's science mission directorate, has cautioned against jumping straight to the E.T. solution on Twitter, noting methane can be created by geological processes. And sadly, as far as we know, rocks are not living beings.

Importantly, Curiosity now has some extra work to do, with a follow-up experiment being conducted over the weekend "to gather more information on what might be a transient plume." NASA notes these unusual methane spikes have been picked up before, but we're not really sure how long they last or what might be causing them. Results from the additional experiment may reach us by as early as Monday, according to the Times.

However, the agency notes Curiosity does not contain instruments which can definitively say where the methane may have come from.

"With our current measurements, we have no way of telling if the methane source is biology or geology, or even ancient or modern," said Paul Mahaffy, SAM principal investigator, in a statement.

Good science relies on follow-up and repeat findings before confirmation, so while it's easy to get excited by the potential for signs of life, a lot more work needs to be done before we can truly confirm the presence of any tiny, underground martian friends. </s> NASA’s Curiosity rover encountered something new on the Red Planet last week and the results could potentially have implications for life on Mars.

The rover’s tunable laser spectrometer, called SAM, which stands for Sample Analysis at Mars, detected the largest amount of methane ever measured during its mission.

The reading indicated 21 parts per billion units by volume or ppbv. That means of the volume of air on Mars is being assessed, one billionth of the volume of air is methane, the agency said.

So why is this unusually large amount of methane so interesting? On Earth, microbial life is a key source of methane. But the agency also warned that expectations of life should be managed due to the fact that interactions between rocks and water can also create methane, and Mars has water and an abundance of rocks.

“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.

The origin of the methane won’t be evident right away because the rover doesn’t have any instruments that can trace or determine the source. Right now, they can’t even be sure that the methane is coming from a spot in the Gale Crater where Curiosity is located or emerged from elsewhere on Mars.

This isn’t the first time methane has been detected on Mars by Curiosity. Over the course of its mission since landing in August 2012, Curiosity has detected methane many times and studies have been written about how the gas levels actually appear to rise and fall depending on the season.

Curiosity has also picked up on spikes of methane, which occur suddenly, but scientists haven’t been able to determine how long the spikes last or why they differ from the known seasonal ups and downs.

The team behind the spectrometer sent an experiment to the rover over the weekend to determine if this is due to a spike, which would appear as a transient plume. Even if no more methane is detected, that could provide more information about the event that was measured.

The science team for Curiosity will take time to study the measurements and prepare for more detections.

They will also reach out to other science teams. The European Space Agency, which launched the Trace Gas Orbiter last year, will be a key collaborator. Their orbiter has yet to detect methane. The two agencies can match up measurements from orbit and the surface.

The two different locations could help scientists determine where gas is originating on the planet and how long it can last in the atmosphere.

In June 2018, organic matter was found on Mars in soil samples taken from 3 billion-year-old mudstone in the Gale crater by the Curiosity rover. The rover also detected methane in the Martian atmosphere.

The search for life outside Earth focuses on the building blocks of life as we know it, which includes organic compounds and molecules — although these can exist without life. Organic matter can be one of several things: a record detailing ancient life, a food source for life or something that exists in the place of life.

No matter its purpose, these work as “chemical clues” for researchers studying Mars.

Methane is considered the simplest organic molecule. It’s present in other places in our solar system that could host life, like Saturn and Jupiter’s moons Enceladus, Europa and Titan. And if life does exist elsewhere, it may be very different or even form differently from how we understand life on Earth.

Over six years, Curiosity has used its Tunable Laser Spectrometer to measure methane in the atmosphere at the Gale Crater. Before, researchers couldn’t understand why the little bit of methane detected in the Martian atmosphere varied. With six years of data from a single location, they now have answers.

There is a seasonal variation to the methane that repeats, which means the methane is being released from the Martian surface or from reservoirs beneath the surface. The methane could even be trapped in water-based crystals beneath the surface.

Methane is a strong greenhouse gas, and it could have supported a climate that sustained lakes on Mars. That could even be happening beneath the surface now. The release of methane is an active process on Mars, which could suggest new things about what’s unfolding on the Red Planet.

Detecting this organic molecule in the atmosphere, combined with the finding of organic compounds in the soil, has strong implications about potential life on Mars in its past.

The Gale Crater was probably habitable 3.5 billion years ago, based on what Curiosity has shown us. Then, the conditions would have been comparable to Earth. This is also when life was evolving on our own planet.

Knowing that these molecules and compounds were present, then, gives new strength to the idea that life originated or existed on Mars and that more work by the Martian rovers can uncover the past. </s> Curiosity, NASA's Mars rover, has had a busy weekend. After detecting the highest levels of methane yet seen on Mars last weekend, NASA put a pause on the rover's other science activities to follow up on the discovery. On Monday, data from Curiosity's subsequent experiment filtered back to NASA and the spike in methane levels had disappeared, dropping to background levels.

"A plume came and a plume went," said Paul Mahaffy, principal investigator overseeing Curiosity's Sample Analysis at Mars (SAM) instrument, during a NASA town hall event at the Astrobiology Science Conference on Monday. "We're very confident of the measurement."

As the news of Curiosity's startling finding broke over the weekend, many suggested the high methane could hint at the possibility of life on Mars. Methane is an important molecule on Earth and many living organisms excrete it, including microbes.

Mahaffy explained that Curiosity had detected an unusually high level of methane last Wednesday during a routine experiment which tests the concentration of molecules in the atmosphere. The data came back on Thursday and showed a methane level of 21 parts per billion -- around three times higher than had ever been seen before. Thus, Curiosity's weekend plans were scrapped to run the experiment again.

"The methane plume went away ... it's back down now to below 1 part per billion," Mahaffy said, noting the measurement is consistent with what has previously been seen on Mars. NASA cautioned as the news broke over the weekend that the methane detection appears to be from a "transient plume" and Curiosity is not outfitted with the appropriate instruments to tell us whether the plume is biological or geological in origin.

What does that mean for life on Mars? Well, not a lot. Although the original finding was confirmed, we're no closer to discovering its source right now -- that will be up to some of the spacecraft orbiting the Red Planet and future Mars missions. Moreover, the methane spike is certainly an unusual phenomenon but it has been seen by scientists before.

"The methane mystery continues," said Ashwin Vasavada, Curiosity's project scientist at NASA, in a statement. "We're more motivated than ever to keep measuring and put our brains together to figure out how methane behaves in the Martian atmosphere."

Using CRISPR to resurrect the woolly mammoth: Bringing extinct species back from the dead is now on the table thanks to the gene-editing technology. Building a rocket in a garage to take on SpaceX and Blue Origin: Gilmour Space Technologies is a plucky startup in the new space race. </s> Image copyright NASA/JPL-CALTECH/MSSS Image caption The Curiosity rover carries an onboard lab to measure the chemistry of the atmosphere

The American space agency's Mars rover Curiosity has recorded its largest measurement yet of methane.

The robot frequently "sniffs" the Red Planet for the gas but has never before seen so high a concentration - of 21 parts per billion (ppb).

The observations are fascinating because on Earth, methane is produced in large part by living things.

That's not necessarily the case on Mars; geological processes are very capable of making it as well.

Nonetheless, the latest data will heighten interest in the topic.

Through the course of its mission, Curiosity has noticed a number of spikes in methane, and it senses a background level that appears to have a seasonal pattern to it.

But although the robot's big onboard chemistry lab - the Sample Analysis at Mars (SAM) instrument - can detect the gas's presence, it can say nothing about the source.

"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 from Nasa's Goddard Spaceflight Center in Greenbelt, Maryland.

The issue of methane at Mars is a little confusing at the moment, to say the least.

While Curiosity continues to measure some spikes, and one of these has been confirmed by the European Mars Express satellite in orbit at the planet - another spacecraft, supposedly with much better sensitivity, has seen nothing.

This probe, known as the Trace Gas Orbiter (TGO), started observing the planet's atmosphere in April 2017. It should be able to detect methane at concentrations in the parts per trillion.

Quite why it cannot see what Curiosity sees is therefore a major puzzle.

One suggestion is that there is some kind of destruction mechanism that removes a methane spike in the lower atmosphere very rapidly - before the joint European-Russian TGO can get over Curiosity's operation site at Gale Crater.

But if this process exists, scientists are at a loss currently to explain it.

Nasa controllers commanded Curiosity to run a further air-sampling experiment over the weekend. The results were expected back on Earth on Monday.

For context, the concentration of methane in Earth's atmosphere is 1,865ppb. So the quantities at Mars, whatever their source, are still very small.

The primary emitters of methane on Earth are from wetlands, livestock, biomass and fossil-fuel burning, landfill and rice paddies.

The term "parts per billion by volume" (ppbv, or ppb for short) means that in a given volume of air, some billionths of that volume will constitute the gas of interest.

One of the geological processes that can produce methane is "serpentinisation", which yields the gas at the end of a chain of reactions when water comes into contact with certain rock minerals.

Dr Mahaffy's statement about historic methane is an important one, too. Even though Curiosity sees the gas today, it is quite possible the original source is ancient and is only now being released into the atmosphere, perhaps because some store below ground has become disturbed.

On Earth, methane can be held in ice under the seafloor or in permafrost regions on land for a very long time before it breaks out into the air. </s> In a finding that has renewed talk about the possibility of life on Mars, NASA said Sunday that its Curiosity rover had detected "unusually high" levels of methane on the Red Planet.

Methane is an odorless, colorless gas that can be produced by simple geological processes as well as by microbes and other living organisms, so the new methane spike doesn't definitively prove that life exists or once existed on Mars.

"While increased methane levels measured by @MarsCuriosity are exciting, as possible indicators for life, it’s important to remember this is an early science result," Thomas Zurbuchen, associate administrator for the science mission directorate at NASA headquarters in Washington, said in a tweet on Saturday.

NASA said Curiosity scientists needed more time to analyze the new findings and to conduct additional methane observations. A spokesperson for the agency declined a request for more information.

Curiosity has detected methane many times since its arrival on Mars in 2012, but this is the most the rover has ever detected: 21 parts per billion by volume. That's three times higher than the previous record, Nature reported, though far below atmospheric methane levels on Earth.

Major sources of methane on Earth include the production and distribution of fossil fuels; cattle and other domestic livestock, which produce methane during the digestive process; and the decomposition of waste in landfills and wastewater treatment plants.

The rover's laser spectrometer device detected the methane while the car-size rover was parked at the Teal Ridge site within Gale Crater, a 96-mile-wide dry lake bed that was created millions of years ago by an asteroid impact. Curiosity was sent to the crater in part because its watery past makes it a likely spot to find evidence of past life on Mars.

Previously, Curiosity detected carbon-containing molecules in ancient sediments on Mars as well as seasonal shifts in the levels of atmospheric methane. In a commentary on those discoveries published last June in the journal Nature, Inge Loes ten kate, an astrobiologist at Utrecht University in the Netherlands, called the discoveries "breakthroughs in astrobiology."
• Apollo moon rocks may unlock more secrets about our solar system

SIGN UP FOR THE MACH NEWSLETTER AND FOLLOW NBC NEWS MACH ON TWITTER, FACEBOOK, AND INSTAGRAM. </s> NASA's Curiosity Mars rover has found the largest amount of methane ever measured during its mission on the Red Planet -- about 21 parts per billion units by volume (ppbv), the US space agency said.

One ppbv means that if you take a volume of air on Mars, one billionth of the volume of air is methane, according to the US space agency.

The finding came from the rover's Sample Analysis at Mars (SAM) tunable laser spectrometer.

It is exciting because microbial life is an important source of methane on Earth, but methane can also be created through interactions between rocks and water, NASA said in a statement.

Curiosity does not have instruments that can definitively say what the source of the methane is, or even if it is 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 the US.

The Curiosity team has detected methane many times over the course of the mission.

Previous papers have documented how background levels of the gas seem to rise and fall seasonally.

They have also noted sudden spikes of methane, but the science team knows very little about how long these transient plumes last or why they are different from the seasonal patterns.

The SAM team has organised a different experiment to gather more information on what might be a transient plume.

Whatever they find -- even if it is an absence of methane -- will add context to the recent measurement, NASA said.

Curiosity's scientists need time to analyse these clues and conduct many more methane observations.

They also need time to collaborate with other science teams, including those with the European Space Agency's Trace Gas Orbiter, which has been in its science orbit for a little over a year.

Combining observations from the surface and from orbit could help scientists locate sources of the gas on the planet and understand how long it lasts in the Martian atmosphere.

That might explain why the Trace Gas Orbiter's and Curiosity's methane observations have been so different, according to NASA. </s> In a finding that has renewed talk about the possibility of life on Mars, NASA's Curiosity rover has detected "unusually high" levels of methane on the Red Planet.

Methane is an odorless, colorless gas that can be produced by simple geological processes as well as by microbes and other living organisms, so the new methane spike doesn't definitively prove that life exists or once existed on Mars.

"While increased methane levels measured by @MarsCuriosity are exciting, as possible indicators for life, it’s important to remember this is an early science result," Thomas Zurbuchen, associate administrator for the science mission directorate at NASA headquarters in Washington, said in a tweet on Saturday.

NASA said Curiosity scientists needed more time to analyze the new findings and to conduct additional methane observations. A spokesperson for the agency declined a request for more information.

"It's interesting, but we should wait a bit to be sure the data are confirmed," Dorothy Oehler, a senior scientist with the Planetary Science Institute in Tucson, Arizona, said of the methane spike in an email to NBC News MACH. Methane seeps from certain types of rocks on Earth and the same types exist on Mars, she said, "so while we cannot exclude a microbial origin for the methane peaks on Mars, that would not be necessary to explain the detections to date."

Curiosity has detected methane many times since its arrival on Mars in 2012, but this is the most the rover has ever detected: 21 parts per billion by volume. That's three times higher than the previous record, Nature reported, though far below atmospheric methane levels on Earth.

Major sources of methane on Earth include the production and distribution of fossil fuels; cattle and other domestic livestock, which produce methane during the digestive process; and the decomposition of waste in landfills and wastewater treatment plants.

The rover's laser spectrometer device detected the methane while the car-size rover was parked at the Teal Ridge site within Gale Crater, a 96-mile-wide dry lake bed that was created millions of years ago by an asteroid impact. Curiosity was sent to the crater in part because its watery past makes it a likely spot to find evidence of past life on Mars.

Previously, Curiosity detected carbon-containing molecules in ancient sediments on Mars as well as seasonal shifts in the levels of atmospheric methane. In a commentary published last June in the journal Nature, Inge Loes ten kate, an astrobiologist at Utrecht University in the Netherlands, called those discoveries "breakthroughs in astrobiology."
• Apollo moon rocks may unlock more secrets about our solar system

SIGN UP FOR THE MACH NEWSLETTER AND FOLLOW NBC NEWS MACH ON TWITTER, FACEBOOK, AND INSTAGRAM. </s> NASA’s Curiosity rover has been exploring the red planet for almost seven years, spending most of its time analyzing the geology and taking selfies. However, it also has some instruments that can detect possible signs of life on Mars. The agency reports that Curiosity just detected an unusually high concentration of methane, a gas that we associate with biological processes.

Curiosity has an instrument called the Sample Analysis at Mars (SAM), a tunable laser spectrometer capable of measuring atmospheric composition. Data from last week showed a methane concentration of 21 parts per billion units by volume (ppbv). That’s more than double what NASA might expect to find on a typical Martian day.

The SAM cannot, however, tell us about the origin of that methane. On Earth, many living organisms release methane, including microbial life. That’s why the presence of methane is considered a potential indicator of life. That’s not the only way to produce methane, though. There are geological processes involving water and certain minerals that can also produce methane. Still, the detection was high enough that the Curiosity team has put other experiments on hold to gather additional data.

Data from Mars shows that methane concentrations cycle seasonally, which may suggest pockets of methane exist below the surface. These reservoirs may be ancient, reflecting past conditions on Mars. Spikes in methane concentration are also common, but the Curiosity team knows very little about what causes them. NASA is currently running more tests to see how the methane concentration changes over time. Whatever Curiosity finds will help us better understand the atmosphere of Mars — a lack of methane could be just as interesting as another high reading. Meanwhile, the ExoMars orbiter has detected almost no methane in the atmosphere during a current test.

While Curiosity can provide us some useful data on methane concentrations, the upcoming Mars 2020 rover will take this work and run (roll) with it. This robot uses the same overall design as Curiosity but will focus more on astrobiology with a suite of instruments keyed to detect biosignatures. It also has more durable wheels that should carry it even farther than Curiosity. This rover could help us determine if life ever existed on Mars or if it still does. Mars 2020 will launch next summer, arriving on Mars in early 2021.
• ExoMars Detects Almost No Methane on Mars in Surprise Result </s> Recent readings on Mars have detected a gas that could be a sign of microbes living on the planet today.

In a measurement taken on Wednesday, NASA's Curiosity rover discovered high amounts of methane, a gas that on Earth is usually produced by living things, in the Martian air. The data arrived back on Earth on Thursday, and by Friday, scientists working on the mission were discussing the news, which has not yet been announced by NASA.

"Given this surprising result, we've reorganized the weekend to run a follow-up experiment," Ashwin Vasavada, the project scientist for the mission, wrote to the science team in an email that was obtained by The New York Times.

The mission's controllers sent new instructions to Curiosity on Friday to follow up on the readings, bumping the rover's scheduled tests. The results of these observations are expected back on Earth Monday.

People have long been fascinated by the possibility of life on Mars. But NASA's Viking landers in the 1970s photographed a desolate landscape. Two decades later, planetary scientists thought Mars might have been warmer, wetter and more habitable in its youth some 4 billion years ago. Now, they are entertaining the notion that if life ever did arise on Mars, its microbial descendants could have migrated underground and persisted.

Sunlight and chemical reactions would break apart methane molecules in Mars' atmosphere within a few centuries, suggesting that methane detected by Curiosity was released recently.

On Earth, microbes known as methanogens thrive in places lacking oxygen, such as rocks deep underground and the digestive tracts of animals, and they release methane as waste. However, geothermal reactions devoid of biology can also generate methane.

It is also possible that the methane is ancient, trapped inside Mars for millions of years but escaping intermittently through cracks.

Scientists first detected methane on Mars a decade and a half ago using measurements from Mars Express, an orbiting spacecraft built by the European Space Agency, as well as from telescopes on Earth. However, those findings were at the edge of the detection power of these tools, and many researchers thought the methane might just be a mirage of mistaken data.

When Curiosity arrived on Mars in 2012, it looked for methane and found less than 1 part per billion in the atmosphere. In 2013, it detected a sudden spike, up to 7 parts per billion, that lasted several months.

The measurement last week found 21 parts per billion of methane, or three times the 2013 spike.

Even before this discovery, the mystery of methane has been deepening.

Curiosity scientists developed a technique that enabled the rover to detect even tinier amounts of methane with its existing tools. The gas seems to rise and fall with the red planet's seasons. A new analysis of old Mars Express readings confirmed Curiosity's 2013 findings. One day after Curiosity reported a spike of methane, the orbiter, passing over Curiosity's location, also measured a spike.

But the Trace Gas Orbiter, a newer European spacecraft launched in 2016 with more sensitive instruments, did not detect any methane at all in its first batch of scientific observations last year.

Marco Giuranna, a scientist at the National Institute for Astrophysics in Italy, who leads the Mars Express orbiter's methane measurements, said scientists on the Curiosity, Mars Express and Trace Gas Orbiter missions had been discussing the latest findings. He confirmed he had been told of the reading of 21 parts per billion but added that the finding was preliminary.
NASA announces that its Curiosity rover has detected the largest ever measurement of methane on Mars.