TIME animals

Gigantic Whales Eat Huge Amounts Thanks to ‘Bungee-Cord’ Nerves

Humpback whale breaches 3 miles off of Rockaway Beach on August 31, 2014 in New York City
Artie Raslich—Getty Images Humpback whale breaches 3 miles off of Rockaway Beach on August 31, 2014 in New York City

The discovery was an accident

Rorqual whales (blue, fin, humpback among others) are not only the world’s largest animals but when they eat they open their mouths to such an extent that they are capable of ingesting a volume of water larger than their own bodies. On Monday, scientists from the University of British Columbia explained how they do this — stretchy nerves.

“These large nerves actually stretch and recoil like bungee cords,” A. Wayne Vogl, an author of the study to be published in May in the journal Current Biology, said in a press release.

Normally, a firm collagen wall surrounds nerves and if stretched they become damaged. For example, humans can suffer from “nerve stretch injury.”

In rorqual whales, the nerves are packed into a centralized core surrounded by limber “elastin fibers.” When the whale opens its mouth the design enables the nerve fibers to unfold. The feeding whale will then gulp-up floating prey before the nerve snaps back and the sea water is filtered through baleen plates in its mouth, leaving behind a massive quantity of small prey.

What’s more, the discovery was an accident. A team member picked up what he believed to have been a blood vessel and stretched it. But upon closer examination the researchers realized that the blood vessel was in actuality a nerve.

The scientists plan to keep studying the whales in the hopes to better understand the folding and unfolding process.

TIME A Year In Space

The Great Space Twins Study Begins

Astronaut twins Mark and Scott Kelly
Marco Grob for TIME Astronaut twins Mark and Scott Kelly

Scott and Mark Kelly—one in space, one on Earth—go under the microscope for science

When serendipity hands scientists the perfect experiment, they don’t hesitate to jump on it. That’s surely the case with NASA’s improbable study of Scott Kelly, who has just completed the first month of a one-year stay aboard the International Space Station, and his identical twin brother Mark, who will spend the same year on Earth.

Zero-gravity messes with the human body in all manner of ways but it’s not always easy to determine which problems are actually caused by the weightlessness and which would have happened anyway. The puzzle gets a lot easier if you just happen to have a second subject with exactly the same genes, the same lifestyle and the same level of fitness. Observe any differences in their health over the year, subtract the matching genetics and what’s left over on the other side of the equal sign is likely the work of weightlessness. Much of the research that will investigate these differences in the Kellys is already underway, both in space and on the ground.

One of the most important studies involves what are known as telomeres, the cuffs that protect the tips of chromosomes in much the way a plastic aglet protects the tips of shoelaces. The longer we live, the shorter our telomeres get, and the unraveling of the chromosomes that results drives the infirmities that come with age.

“One of the things that comes up almost all the time in the interviews with Mark and Scott is this idea of the twin paradox,” says Susan Bailey, of Colorado State University, who is coordinating the telomere research. “Is the space twin going to come back younger than the Earth twin?” That kind of time dilation happens in movies like Interstellar, but only when someone is moving at close to light speed. The year Scott will spend orbiting Earth at 17,500 mph (28,000 k/h), may indeed slow his body clock, but by barely a few milliseconds. His telomeres, however, will more than make up for that, and he’ll likely come home physically older than Mark.

“A whole variety of life stresses have been associated with accelerated telomere loss as we age,” says Bailey. “You can imagine strapping yourself to a rocket and living in space for a year is a very stressful event.”

Chromosomal samples from both Kelly twins were taken and banked before Scott left to provide a telomere baseline, and more samples will be collected over the year. Mark’s are easy enough to get ahold of, but Scott will have to draw his own blood in space, spin it down and freeze it, then send it home aboard returning ships carrying cargo or astronauts. Both twins will also be followed for two years after Scott comes back to determine if any space-related telomere loss slows and if the brothers move closer to synchrony again.

The twins’ blood samples will also be used to look for the state of their epigenomes, the chemical on-off switches that sit atop the genome and regulate which genes are expressed and which are silenced. Environment is a huge driver in epigenetic changes, especially in space, as cells adjust to the unfamiliar state of weightlessness. “We can kind of build these molecular maps of what’s happening in the different cells…as they’re challenged by this low gravity condition,” says geneticist Chris Mason of Weill Cornell Medical Center in New York City, who is leading this part of the work.

Also due for a good close look are Scott’s and Mark’s microbiomes. The number of cells that make up your body are actually outnumbered 10 to one by the bacteria, viruses, yeasts and molds that live in your body. It’s only the fact that most of them are also much smaller than human cells that prevents them from outweighing you 10 to one as well. Still, if you could extract them all and hold them in your hand they’d make a hot bolus of alien organisms weighing up to 5 pounds.

This is actually a good thing, since we need this interior ecosystem to keep our bodies—especially our digestive tract—running smoothly. Like so much else for Scott, that will change in space. “A significant part of what’s present normally in the gastrointestinal tract doesn’t actually colonize,” says research professor Martha Vitaterna of Northwestern University, co-investigator on the microbiome work. “These are things that are constantly being reintroduced with fresh fruits and vegetables, and that’s missing from Scott’s diet.”

Genes can also make a difference to the microbiome, since any individual’s genetic make-up may determine which microorganisms thrive in the gut and which don’t. Scott’s and Mark’s microbiomes will be compared throughout the year, principally through stool samples—ensuring some unglamorous if scientifically essential shipments coming down from space.

Other studies will involve the way body fluids shift in zero-g, drifting upwards to the head and elsewhere since there is no gravity pulling them down. This can damage vision as a result of pressure on the eyeballs and optic nerve. It can also lead to damage to the cardiovascular system, with astronauts returning to Earth at increased risk of atherosclerosis.

Some of these changes can be tracked by blood studies, which will look for proteins that regulate water excretion. Ultrasound scans can also look for vascular damage. Before leaving Earth, Scott had a few small dots tattooed on his upper body to indicate the exact points at which he has to position the ultrasound probe—easier than taking precise measurements to find the proper spots every time he’s due for a scan.

Multiple other studies will be conducted on the twins as well, looking at their immune systems, sleep cycles, psychological states and more. For years, space planners have been talking a good game about going to Mars one day, but those trips will last more than two years. We know the hardware can survive the trip; what we don’t know is if the human cargo can. A year from now—thanks to the Kellys—we’ll be a lot smarter.

TIME is covering Kelly’s mission in the new series, A Year In Space. Watch the trailer here.

TIME Biology

Here’s Why You Have a Chin

Gorgeous—and pretty much useless
Chev Wilkinson; Getty Images Gorgeous—and pretty much useless

Hint: You could do perfectly well without it

Nature is nothing if not parsimonious, especially when it comes to the human body. There’s a reason we don’t have webbed feet or nut-cracking beaks like other species, and that’s because we don’t need them. The system isn’t perfect, of course. If you ever wind up having painful abdominal surgery, odds are pretty fair that it will be your good-for-nothing appendix that’s to blame. And wisdom teeth seem a lot less wise when you consider how often they fall down on the job and need to get yanked.

As it turns out, the same why-bother pointlessness is true of what you might consider one of your loveliest features: your chin.

Researchers have long wondered what the adaptive purpose of the chin could possibly be. Sexual selection seems like an obvious answer, since an attractive chin increases your chances of mating. But a feature needs a function before it can appear in the first place. Only then can it be assigned some aesthetic value.

The other, better answer is all about chewing. The jaw exerts enormous forces when it bites and chews—up to 70 lbs. per sq. in. (32 kg per 6.5 sq. cm) for the molars. Conscious clenching increases the figure, and people who grind their teeth in their sleep may exceed the average force 10-fold. What’s more, the jaw moves in more than just one axis, both chewing up and down and grinding side to side.

That, so the thinking went, might increase bone mass in the same way physical exercise builds muscle mass. And bone mass, in turn, may produce the chin. The problem with the theory, however, is that it doesn’t account for Neanderthals and other primates—including the great apes—which lack prominent chins but in many cases have far more powerful bites than we do.

To answer the riddle, Nathan Holton, a post-doctoral researcher who specializes in craniofacial structure in the University of Iowa school of orthodontics, selected 37 of the many subjects whose facial measurements have been taken regularly from age 3 to young adulthood, as past of the longstanding Iowa Facial Growth Study (yes, there is such a thing).

With the help of basic physics, it’s possible to determine how much force any one jaw exerts without the subjects’ ever having to be tested directly with a bite gauge. Measuring the geometry of what orthodontic researchers call the mandibular symphysis and what everyone else just calls the chin region, and comparing that to what is known as the bending moment arm—or the distance between where a force is initially applied (in this case the muscles in the jaw) and where that force is eventually felt (the chin)—yields a pretty good measure of force exerted.

“Think about removing the lug nuts from a wheel on your car,” Holton wrote in an e-mail to TIME. “The longer the wrench, the easier it is because the longer wrench increases the moment arm, allowing you to create more force.”

And more force, in this case, should mean more bone mass in the chin—but that’s not what the results of the new research showed. Not only did the two turn out to be unrelated in the 37 subjects studied, but Holton and his colleagues even found that as the face matures, the chin is less adept at resisting mechanical forces, which is the whole reason it was assumed to grow more pronounced in the first place.

So why did we grow chins at all? The answer is, we didn’t. Holton and his collaborator, University of Iowa anthropologist Robert Franciscus, instead suspect that the face shrank away from behind the chin as primitive and pre-humans became modern humans, making it appear larger relative to everything else. The reason, as with so many things in the human species, has to do with male behavior—specifically violent male behavior.

As humans migrated from Africa 20,000 years ago and settled down into societies, males had to become less competitive and more cooperative—giving an advantage to those with lower testosterone levels. And reduced testosterone softens and shrinks the craniofacial structure.

“What we are arguing is that modern humans had an advantage at some point to have a well-connected social network,” Franciscus said in a statement accompanying the study. “And for that to happen, males had to tolerate each other. There had to be more curiosity and inquisitiveness than aggression, and the evidence of that lies in facial architecture.”

It wasn’t until we had our chins that we set about assigning value to them—strong ones, weak ones, angular, round, cleft or dimpled, depending on your tastes. Those tastes—and the mating choices that arise from them—ensure that the chin will stay. It might be biomechanically useless, but you’d look awfully silly without one.

Read next: Can Plastic Surgery Make You More Likeable? A Close Look at a New Study

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TIME space

Maybe We Really Are Alone In the Universe

Jeffrey Kluger is Editor at Large for TIME.

As a new TIME book explains, a cosmos with trillions of planets does not guarantee more than one with life

You may as well get a lot friendlier with life on Earth—every microbe and mammal, every bird and bug, and especially every human being. Because when it comes to biology, our planet may be the whole show.

Forget the overwhelming math—those trillions upon trillions of planets that are likely out there, at least some of which should be inhabited. Snuff out the one match head that is life on Earth, and the whole universe goes biologically black. We can search for biology all we want, send up all the here-we-are signal flares we can invent, but the fact is, no one will answer—ever—because no one is there.

That, like it or not, may be the truth, and it’s not just the picnic skunks who say so. Some very credible researchers have crunched the numbers and run the odds and taken a good hard look at them without the little frisson of hope even many of the most serious scientists bring to their work—and they come up empty. That’s not easy to accept because for a long time other, equally credible scientists have made a strong case for alien life.

Perhaps the most influential of the life-is-out-there advocates, astronomer and SETI Institute founder Frank Drake, made his bones in the extraterrestrial game with his eponymous equation, a satisfying—if coldly arithmetical—case for the likelihood not only of life in space but of intelligent life. According to Drake, the n in his equation—the number of civilizations in the Milky Way alone capable of producing detectable radio signals—equals the rate of the formation of sunlike stars in our galaxy, times the proportion of stars that are orbited by planets, times the proportion of those planets that would offer life-supporting conditions, times the fraction of those on which life does exist, times the fraction of life-forms that are intelligent, times the fraction of intelligent life-forms capable of transmitting signals, times the length of time such a civilization actually sends those signals before either perishing or going silent for any other reason.

Simple, right? Honestly, it kind of is. Filling in all of the x’s in the Drake equation—which, admittedly, is itself an act of conjecture, albeit highly informed conjecture—typically yields an estimate of thousands of civilizations. Drake himself put it at 10,000. The late cosmological popularizer Carl Sagan estimated the figure at an astounding 1 million. Even if they were off by a factor of 10 or 100 or 1,000, it is clear we are not remotely alone.

Unless we are.

Paul Davies, a cosmologist at Arizona State University and the author of the book Eerie Silence—which takes exactly the dim view of our ever encountering an alien intelligence that its title suggests—finds almost no part of the intelligent-life argument persuasive. The biggest hole he finds in the Drake equation is the one involving the subset of planets that could support life that actually do. The fact is, we have absolutely no empirical data that allows us to put a value on that variable in a responsible way. We know of precisely one world on which life has existed, and the rest is largely guesswork. Fill in that one Drake blank with a zero, and the entire equation collapses to zero too.

Davies, though, goes well beyond the flaws of the equation, arguing that there is a perfectly credible case to be made for the presence of life on Earth as a result of a succession of flukes, each more improbable than the one before it, which, together, could occur only a single time in a trillion trillion tries. A chimp randomly pounding a typewriter might indeed come up with Hamlet. Once. It wouldn’t matter if there were 40 billion other chimps hammering away, just as, as Davies has written, it doesn’t matter if there are 40 billion planets in the Milky Way capable of sustaining life. Only a single one will.

Furthermore, he believes that in the improbable event an intelligent civilization exists, it is surpassingly unlikely it would send any messages our way. The popular notion is that because we’ve been transmitting radio and TV signals for more than a century—and because those signals are spreading into space at the speed of light—surely a sophisticated species would have gotten wind of us. Problem is, in a universe that stretches for 13.8 billion light-years in all directions, the 100 light-years our signals have traveled so far make them a decidedly local broadcast.

Most discouraging is that in all the years we’ve been looking for an extraterrestrial sign (and no, crop circles don’t count), there has been, well, only an eerie silence. SETI’s antennas have been pointed skyward for half a century, listening for a repeating signal that would suggest an intelligent sender; so far, nothing. There was one thrilling moment—on Aug. 15, 1977—when SETI scientist Jerry Ehman, working with Ohio State University’s radio telescope, picked up a signal a full 30 times as strong as the background noise of deep space. It was tracked for 72 seconds and had a frequency similar to that of the spectral line for hydrogen. (That’s relevant because SETI scientists have long believed that since hydrogen is the most common element in the universe, it might be chosen as a sort of universal sending frequency.)

On the printout that the radio telescope produced of the signal, Ehman wrote one word: “Wow!” Forevermore, what he heard that night has been known as the Wow! signal. It was never heard again, though, and today it is assumed to have been an atmospheric anomaly, a reflection from space debris or of earthly origin. What it almost certainly was not was an alien semaphore.

Of course, it’s much too early to consider any of this proof of a negative. The universe is huge and ancient, and a 50-year exploration isn’t even a single pixel in the sweeping mural of time. Science does make hard, sudden turns: one day there was no Copernicus saying the Earth isn’t the center of the universe, and then there was—and nothing was ever the same again. Ditto Einstein and his relativistic universe; ditto Leeuwenhoek and the previously unseen biosphere revealed by his microscope. And so it could still be with the discovery of alien life.

Until then, there may be something to be gained from thinking of the Earth as the universe’s only wilderness preserve. If life is indeed a cosmic one-off, it makes it all the more important that we act as this planet’s responsible caretakers. Snuff this biological light, and the descending darkness won’t just be our fault. It will be our crime.

Read next: Watch the Total Solar Eclipse in 5 Seconds

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TIME Ideas hosts the world's leading voices, providing commentary and expertise on the most compelling events in news, society, and culture. We welcome outside contributions. To submit a piece, email ideas@time.com.

TIME Innovation

Five Best Ideas of the Day: March 5

The Aspen Institute is an educational and policy studies organization based in Washington, D.C.

1. 2.7 million American children have a parent in prison. We can learn from South Africa’s belief in a “right to childhood.”

By Lauren Lee White at the USC Center on Public Diplomacy

2. Imagine handling an ancient artifact or typing on a virtual keyboard. Holograms you can feel are here.

By Anthony Cuthbertson in International Business Times

3. One school district is bringing down the silos between art, computer science and technology education to give kids skills for the future.

By Todd Keruskin in EdSurge

4. They cost less and give patients a better experience. It’s time to drop the barriers on nurse practitioners.

By Matthew Yglesias in Vox

5. To keep their labs supplied with cheap labor, universities are churning out PhDs. But there’s no work for them after graduation.

By Brenda Iasevoli in The Hechinger Report

The Aspen Institute is an educational and policy studies organization based in Washington, D.C.

TIME Ideas hosts the world's leading voices, providing commentary and expertise on the most compelling events in news, society, and culture. We welcome outside contributions. To submit a piece, email ideas@time.com.

TIME Research

A Rough Childhood Can Literally Age You Says a New Study

458909847
Getty Images

Researchers say childhood adversity and psychiatric disorders may be linked to cellular changes that cause aging

Childhood trauma and psychiatric conditions may cause individuals to experience accelerated aging, according to research published last week.

In a study featured in Biological Psychiatry, scientists say they may have found evidence to suggest there is a link between aging at the cellular level and trauma or stress disorders.

To complete the study, researchers recruited 299 adults and separated them into different groups based on their experiences with childhood adversity, depression, anxiety or substance abuse.

The participants then had their DNA analyzed to study the lengths of their telomeres and any alterations to mitochondrial DNA (mtDNA). Telomere shortening and higher mtDNA content can serve as a yardstick to measure cellular aging.

“Results of the study show childhood adversity and lifetime psychopathology were each associated with shorter telomeres and higher mtDNA content,” read the report.

These effects were seen particularly in adults who had battled with major depression and anxiety disorders, along with parental loss or childhood maltreatment.

“Identifying the changes that occur at a cellular level due to these psychosocial factors allows us to understand the causes of these poor health conditions and possibly the overall aging process,” said Audrey Tyrka, associate professor of psychiatry and human behavior at Brown University.

[Science Daily]

TIME space

Cousins of Earth Found Deep in Space

Don't blink: This has been Kepler's field of vision for most of its time aloft as it has searched for tiny flickers around candidate stars
NASA Don't blink: This has been Kepler's field of vision for most of its time aloft as it has searched for tiny flickers around candidate stars

A flock of planets in their suns' habitable zones boost the odds for extraterrestrial life

When NASA scientists declared the planet-hunting Kepler telescope hopelessly crippled in the fall of 2013, the mission’s founding father and principal investigator Bill Borucki pointed out that its useful life wasn’t necessarily over. For one thing, there was reason to believe Kepler could use some clever engineering tricks to keep finding new worlds—which it has. For another, the probe had collected such mountains of data since its 2009 launch that it would take months or even years to plow through it all. There could well be major discoveries to emerge as the backlog was gradually processed.

Turns out he was right. Speaking at the American Astronomical Society’s winter meeting in Seattle today, astronomers announced the discovery of eight planets orbiting in their stars’ “Goldilocks Zone”—the region where temperatures are just right for water to exist in liquid form, a requirement for life as we know it.

“We’re not claiming they’re inhabited,” emphasizes Guillermo Torres, of the Harvard-Smithsonian Center for Astrophysics, lead author of a paper that describes the newly identified worlds. But astronomers do know that if a planet has significant amounts of water on its surface, and if it has a heat-trapping atmosphere like Earth’s, it’s ticked off two very important items on the biology checklist.

That’s the case, at least, if the planet has a surface—and unlike many of the exoplanets discovered so far, at least four of these worlds almost certainly do: they’re small enough to be rocky like Earth, not mammoth gas blobs like Jupiter or Neptune. One of the planets, known as Kepler 182f, was already described by another group last year, so this is more of a rediscovery. At the time, 182f was by far the Earthiest planet ever found, given its size and likely temperature. But two of the brand-new ones, says co-author David Kipping, also of Harvard, known as Kepler 438 and 442, respectively, are even more tantalizing. Kepler 182f is technically in its star’s habitable zone, but is thought to be quite cold nonetheless, at the outer edge of what is considered a good candidate for life.

Kepler 438, however, is just 10 percent larger than Earth and gets about 40 percent more energy from its star than Earth itself does, while 442, which is 20 percent larger than Earth, gets about 30 percent less. Neither is a perfect match, but both are better than 182f.

The bad news is that like the vast majority of Kepler planets, these new ones are too far away to be examined directly for signs of life, even with the next generation of giant Earth and space-based telescopes currently on the drawing boards. They’re also too distant for their existence even to be confirmed with 100 percent certainty. Kepler does its work by looking for a slight dimming of a parent star as a planet passes in front of it. But since other effects can produce a similar dimming (a background star passing in front of another one, for example), the gold standard for confirmation is to measure the gravitational tug a planet exerts on the star it orbits. If the wobble is there, and if its rhythm matches that of the dimming, it’s a slam dunk.

That can’t be done in this case since Kepler was not designed to analyze wobble, but the astronomers were able to accomplish the next best thing: they used software known as “Blender” to simulate all of the ways a planet candidate might be fooling observers and rule them in or out. In this case, says Kipping, the new finds have “been validated with 99.73 percent confidence as true planets.”

There’s one more thing, aside from their slightly larger size and the somewhat different levels of energy they absorb that keeps these planets from being true twins of Earth: they orbit “orange dwarf” stars that are smaller and dimmer than the Sun. But in some ways, that actually makes them more promising. Back in the days of the first exoplanet discoveries in the 1990’s, nobody was thinking much about anything but planets around Sun-like stars as possible places life might exist.

The discovery that a different species of star can be home to at least a distant cousin of Earth only widens the category of worlds on which biology might have taken hold. At the moment, we are still—as far as we know—alone in the universe. But that’s a moment that could be coming to an end soon.

TIME animals

Newly Discovered Fanged-Frog Gives Birth to Live Tadpoles

A newly discovered frog from the island of Sulawesi in Indonesia is the only known frog to give direct birth to tadpoles.
Jim McGuire—UC Berkeley A newly discovered frog from the island of Sulawesi in Indonesia is the only known frog to give direct birth to tadpoles.

As opposed to eggs, like most frogs

Scientists have discovered a rare frog in Indonesia that gives birth to live tadpoles, researchers report in a journal article published this week.

Herpatologist Jim McGuire found proof this summer that the frog, one of a group of roughly 25 species in Indonesia that have two fangs used for fighting, lays not eggs or even live froglets but live tadpoles. It’s the only frog species in the world to do so.

McGuire found the frogs on the Indonesian island of Sulawesi. He named to the species Limnonectes larvaepartus.

Jim McGuire—UC BerkeleyTwo tadpoles, each about 10 millimeters long, shortly after birth.

[Eureka]

TIME Biology

Smartphone Use Makes Your Brain More Sensitive to Touch

Apple Launches iPhone 5s And 5c In China
Lintao Zhang—Getty A customer inspects the new iPhone at the Wangfujing flagship store on September 20, 2013 in Beijing, China.

New study finds that brain activity is enhanced the more we thumb our devices

Swiping fingers across a smartphone screen can make the brain more sensitive to the touch of the finger tips, a new study suggests.

The study, published in Current Biology this week, shows that brain response to thumb stimulation is partly explained by how often people use their smartphones, reports the Washington Post.

“I was really surprised by the scale of the changes introduced by the use of smartphones,” said Arko Ghosh, one of the study’s authors from the Institute of Neuroinformatics at the University of Zurich.

Researchers recorded brain activity when people touched their thumbs, index and middle fingers to a mechanical object. Smartphone users broadcasted increased activity compared to non-smartphone users, and the activity was boosted the more people used their devices.

[Washington Post]

TIME space

Odds For Life on Mars Tick Up—a Little

High-tide: layering in a Mars rock photographed by Curiosity suggests the movement of long-ago water
NASA/JPL High-tide: layering in a Mars rock photographed by Curiosity suggests the movement of long-ago water

New findings about both methane and water boost the chances for biology

September of 2013 was a bad time for those who hope there’s life on Mars. We’ve had evidence for decades that water flowed freely across the surface of the Red Planet billions of years ago, and that evidence has only gotten stronger and stronger the closer we look. Not only was there potentially life-giving water back then: Mars also had the right kind of geology to support mineral-eating microbes. And while all of that was in the distant past, the detection of methane in the Martian atmosphere by Earth-based telescopes and Mars orbiters raised hopes that bacteria might still be thriving below the surface—not unreasonable, both because all manner of Earthly critters do perfectly well below-ground and because the vast majority of methane in our own atmosphere results from biological activity. Mars’s methane might come from a similar source.

But when the Curiosity rover sniffed the Martian air directly last year, it smelled…nothing. At most, there were just three parts per billion (ppb) of methane wafting around, and possibly much less than that. “We kind of thought we’d closed that chapter,” says Christopher Webster of the Jet Propulsion Laboratory, lead scientist for the instrument that did the sniffing. “A lot of people were very disappointed.”

Not any more, though. Just weeks after that dismal reading, Curiosity’s Tunable Laser Spectrometer (TLS) picked up a whiff of methane at a concentration of 5.5 parts per billion. “It took us by surprise,” says Webster, and over the next two months, he says, “every time we looked there was methane. Indeed, the concentrations even rose, to an average of 7.2 ppb over that period, he and his colleagues report in a new paper in Science.

And then, six weeks later, the methane was gone, and hasn’t been sniffed since. “It’s a fascinating episodic increase,” Webster says.

What he and his colleagues can’t say is where the methane is coming from. Because it’s transient, they think it’s probably from a fairly local source. But whether it’s biological or geological in origin, they don’t know. It’s wise to be cautious, however, says Christopher Chyba, a professor of astrophysics and international affairs at Princeton. “Hopes for biology on Mars have had a way of disappearing once Martian chemistry has been better understood. But figuring out what’s responsible for the methane is clearly a key astrobiological objective—whatever the answer turns out to be.”

That’s not the only important Mars-related paper in Science this week, either. Another, also based on Curiosity observations, concerns Mars’s long-lost surface water, and one of the most important points is that there’s a lot more of it left than most people realize—”enough,” says Jet Propulsion Laboratory scientist Paul Mahaffy, lead author of the paper, “to cover the surface to a depth of 50 meters [about 165 ft].” That doesn’t mean it’s accessible: it’s nearly all locked up in ice at the planet’s poles, but some is also entrained in the clay Curiosity dug into when it was prowling the Yellowknife Bay area of Gale Crater.

Some of that water, says Mahaffy, is tightly chemically bound to the clay and is not a big player in Mars’s modern environment. Some is not quite so locked down and has been interacting with the tenuous Martian atmosphere for the past three billion years. The hydrogen in Martian water, as in Earthly water, may contain both a single proton and a single electron, or a proton and electron plus a neutron—so-called heavy hydrogen, or deuterium. As the Martian atmosphere has thinned over the eons, the ratio of hydrogen to deuterium in the water has gradually been dropping, as the lighter version escapes more easily into space. Since the modern water is twice as rich in deuterium as the water from billions of years ago, that suggests that there was about twice as much surface water in total at the earlier time, but its hydrogen residue has vanished.

“That’s a fair bit of water,” says Mahaffy, “but it’s a lower limit. There could be much more beneath the surface today that we haven’t seen. It was a really interesting time. There were a lot of aqueous processes going on, and a lot of flowing water.”

Where there is (or was) water, there could be (or could have been) life. For Mars enthusiasts, that’s why December of 2014 is a lot better than September of 2013.

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