The revival of the auto industry is perfectly fine, but the hottest car around is a decidedly limited-edition one: the Opportunity rover, now celebrating its tenth year working and roving on the Red Planet. Like any old car, Opportunity has its flaws: one of its six wheels is shot, not all of its instruments are working as they once did and its robotic arm has dust in its joints. But the golf-car-sized vehicle, which came with just a three-month warranty (admittedly a low-ball figure that NASA engineers suspected it would easily beat) has lasted far longer than even the most optimistic mission planners predicted—and fours years longer than its sister rover, Spirit, which arrived on Mars at around the same time and winked out in 2010. In that decade, Opportunity has put more than 23 mi. (37 km).on its odometer and is still on the move. Opportunity went to Mars to do science, and it’s delivered splendidly on that score—with data streaming back about the chemistry and geology of Mars both today and in its distant past, and tantalizing hints to its biological potential. But humans are visual creatures, and it’s the pictures from the rovers—a small collection of which follow—that will always thrill us most. Happy birthday, Opportunity—and keep rolling.
Scientists fear California's long-ago era of mega-droughts could be back
As he gave his State of the State speech yesterday, California Gov. Jerry Brown had reason to feel pretty good. The 75-year-old governor has helped rescue the state from fiscal insolvency and presided over the addition of 1 million new jobs since 2010. But as he spoke, Brown hit a darker note. Last week, amid the driest year for the state since record-keeping began in the 1840s, Brown declared a drought emergency for California, and in his speech he warned of harder times ahead:
Among all our uncertainties, weather is one of the most basic. We can’t control it. We can only live with it, and now we have to live with a very serious drought of uncertain duration…We do not know how much our current problem derives from the build-up of heat-trapping gasses, but we can take this drought as a stark warning of things to come.
(MORE: Can GM Crops Bust the Drought?)
Californians need to be ready, because if some scientists are right, this drought could be worse than anything the state has experienced in centuries. B. Lynn Ingram, a paleoclimatologist at the University of California, Berkeley, has looked at rings of old trees in the state, which helps scientists gauge precipitation levels going back hundreds of years. (Wide tree rings indicate years of substantial growth and therefore healthy rainfall, while narrow rings indicate years of little growth and very dry weather.) She believes that California hasn’t been this dry since 1580, around the time the English privateer Sir Francis Drake first visited the state’s coast:
If you go back thousands of years, you see that droughts can go on for years if not decades, and there were some dry periods that lasted over a century, like during the Medieval period and the middle Holocene [the current geological epoch, which began about 11,000 years ago]. The 20th century was unusually mild here, in the sense that the droughts weren’t as severe as in the past. It was a wetter century, and a lot of our development has been based on that.
Ingram is referring to paleoclimatic evidence that California, and much of the American Southwest, has a history of mega-droughts that could last for decades and even centuries. Scientists like Richard Seager of Columbia University’s Lamont-Dohery Earth Observatory have used tree-ring data to show that the Plains and the Southwest experienced multi-decadal droughts between 800 A.D. and 1500 A.D. Today dead tree stumps—carbon-dated to the Medieval period—can be seen in river valley bottoms in the Sierra Nevada mountains, and underwater in places like California’s Mono Lake, signs that these bodies of water were once completely dry. Other researchers have looked at the remains of bison bones found in archaeological sites, and have deduced that a millennium ago, the bison were far less numerous than they were several centuries later, when they blanketed the Plains—another sign of how arid the West once was. The indigenous Anasazi people of the Southwest built great cliff cities that can still be seen in places like Mesa Verde—yet their civilization collapsed, quite possibly because they couldn’t endure the mega-droughts.
In fact, those droughts lasted so long that it might be better to say that the Medieval West had a different climate than it has had during most of American history, one that was fundamentally more arid. And there’s no reason to assume that drought as we know it is the aberration. Ingram notes that the late 1930s to early 1950s—a time when much of the great water infrastructure of the West was built, including the Hoover Dam—may turn out to have been unusually wet and mild on a geologic time scale:
I think there’s an assumption that we’ll go back to that, and that’s not necessarily the case. We might be heading into a drier period now. It’s hard for us to predict, but that’s a possibility, especially with global warming. When the climate’s warmer, it tends to be drier in the West. The storms tend to hit further into the Pacific Northwest, like they are this year, and we don’t experience as many storms in the winter season. We get only about seven a year, and it can take the deficit of just a few to create a drought.
These mega-droughts aren’t predictions. They’re history, albeit from a time well before California was the land of Hollywood and Silicon Valley. And the thought that California and the rest of the modern West might have developed during what could turn out to be an unusually wet period is sobering. In 1930, a year before construction began on the Hoover Dam, just 5.6 million people lived in California. Today more than 38.2 million live in the largest state in the U.S., all of whom need water. California’s 80,500 farms and ranches produced crops and livestock worth $44.7 billion in 2012, but dry farming districts like the Central and Imperial Valleys would wither without irrigation. (Altogether, agriculture uses around 80% of the stare’s developed water supply.) More people and more crops have their straws in California’s water supply. Even in normal years, the state would be in trouble. If we see a return to the bone-dry climate of the Medieval period, it’s hard to see how the state could survive as it is now. And that’s not even taking the effects of climate change into account—the most recent Intergovernmental Panel on Climate Change (IPCC) report found that it was likely that warming would lead to even drier conditions in the American Southwest.
In his speech, Brown told Californians “it is imperative that we do everything possible to mitigate the effects of the drought.” The good news is that the sheer amount of water we waste—in farms, in industry, even in our homes—means there’s plenty of room for conservation. The bad news is that if California lives up to its climatological history, there may not be much water left to conserve.
A new study finds that a plant pathogen could play a role in honeybee colony collapse disorder
Honeybees are dying. In the winter of 2012-2013, one-third of U.S. honeybee colonies died or disappeared, a 42 percent increase from the year before and well above the 10-15 percent losses beekeepers once thought was normal. Many of them have been hit by colony collapse disorder (CCD), a mysterious and still unexplained malady that wipes out honeybee hives. Given that honeybees pollinate about one in every three mouthfuls of food you eat—adding some $15 billion worth of value to crops each year—this is a big deal. And we don’t know why they’re dying.
As I wrote in a cover story for TIME last summer, there’s no shortage of possible causes. Agricultural pesticides, Varroa destructor mites, the Israeli paralytic virus (IASV), the loss of open wilderness—each and every factor could play some role in the death of the bees. But there’s been no single smoking gun—which has made it that much tougher to save the bees.
(MORE: The Plight of the Honeybee)
A new study, though, may shed more light on the beepocalypse. Researchers at the USDA’s Agriculture Research Laboratory, as well as academics in the U.S. and China, have found evidence of a rapidly mutating plant pathogen—the tobacco ringspot virus (TRSV)—that seems to have jumped into honeybees, via the pollen bees collect as they fly from flower to flower. The study, published in the journal mBio, found that the virus spread systematically through infected bees and hives, reaching every part of their bodies except the eyes.
While it’s not yet clear how TRSV spreads among honeybees, or what it may do to the infected—though researchers theorize it attacks the nervous system—the study found that the presence of TRSV, along with other bee viruses like IASV, was correlated with lower rates of honeybee colony survival over winters.
Part of what makes TRSV so worrying is that it’s an RNA virus, like HIV and the influenza virus in humans, which allows it to rapidly mutate and evade its hosts’ immune defenses. As a plant virus that has found a way to jump the species barrier, TRSV could be especially tricky. Cross-species pathogens are so new that hosts generally have no defense against them.
Still, this virus isn’t acting alone. The researchers found that the virus was present in Varroa mites, blood-sucking parasites that have killed millions of bees in the U.S. since being introduced in the late 1980s. It’s possible that the mites could help spread the virus from bee to bee and colony to colony, or could weaken the honeybees enough to make them more susceptible to new pathogens like TRSV. The more we learn about CCD, the more it seems as if bees are suffering from a host of ills—pathogens and pesticides and nutritional problems—all interacting in ways we haven’t yet untangled. TRSV is far from a smoking gun, but it could be a very big bullet.
(PHOTO: The Bee, Magnified)
The philanthropist explains why a reduction in child mortality hasn't led to an increase in population growth
It’s easy to get fed up when you’re trying to save the world. Progress can be slow, setbacks are constant and few people appreciate exactly what you’re doing. Bill Gates understands that better than most. Having spent the past 13 years battling poverty, hunger and disease around the world through the Bill & Melinda Gates Foundation, he has a right good record of success to point to, but public misconceptions persist.
In their 2014 annual letter, both Bill and Melinda Gates take on what they call the three great global-aid myths: that poor countries will always be poor; that foreign aid is a waste, with money inevitably vanishing into the pockets of corrupt officials or being misspent by inept bureaucracies; and that saving lives in the developing world will only lead to overpopulation.
The myths persist despite the fact that Africa is experiencing something of a boom time. Demographers document a paradoxical reduction in population in countries where child mortality goes down. As families can be more confident their babies will survive, they will have fewer of them. And as for corruption: yes, it exists, but the incidence has plummeted — thanks in part to the results-based way the Gates Foundation and others administer their programs — and try to name a country in the world that doesn’t have at least a few corrupt officials.
“Four of the past seven governors of Illinois have gone to prison for corruption,” Bill Gates wrote in his letter, “and to my knowledge, no one has demanded that Illinois schools be shut down or its highways be closed.”
Gates elaborated on these and other ideas in a conversation with TIME this morning. As his answers show, he remains both optimist and realist.
You seem hopeful about our ability to lift nations out of poverty permanently. That’s an awfully bold position given how intractable the problem has always been. What evidence do you have that we’re winning the war?
Look at the numbers. If you go back to 1800, everybody was poor. I mean everybody. The Industrial Revolution kicked in and a lot of countries benefited, but by no means everyone. Even in the 1950s and 1960s, most countries were very poor. India, China, Africa, everyone but the West was living on less than $2 a day per capita. But the curve is shifting and incomes are rising and now most of those countries have $5- to $10-a-day-type incomes. That doesn’t sound like much, but it’s per person not per family and the key thing is purchasing power, which can be quite high on $10 per day in a country in which things cost much less. Living on $6 a day means you have a refrigerator, a TV, a cell phone, your children can go to school. That’s not possible on $1 a day.
How does the kind of global aid the Gates Foundation often provides — vaccine development and delivery, say — help countries get richer?
When you invent the vaccines that make kids healthy, you remove a burden from the countries’ health care and social systems. Aid creates health and nutrition, and health and nutrition creates wealth. Healthy children can go to school and work and contribute to their country’s economy. Yes, it’s hard to see the benefits right away and that often misleads people. Health improvements pay off a generation down the line.
What about the dependency issue? Don’t recipient countries come to rely on aid?
Mexico was once a recipient country. So was Brazil and so was China and now they’re all donor countries. The key is the kind of aid you provide. When you invent seeds that produce heartier crops in diverse climates, you help farmers become more productive, for example, and that has perhaps the biggest impact on a developing country. Clearly, having stability, having a capitalist economy helps too. China adopted a capitalist system in the 1980s, and they went from a 60% poverty rate to 10%.
No one ever advocated simply letting countries with high infant-mortality rates suffer, but most did believe that reducing deaths would mean exacerbating overpopulation. Now we’re finding the opposite is true. How did that happen?
Actually demographers were seeing drops in population rates as kids stopped dying some time ago. The people who did population projections went year after year tracking this, and by the 1990s this idea was pretty well-known but only in certain circles. It was only recently, as we started working with contraception, that I understood it myself. Families in wealthier, healthier countries have fewer children because the odds are better that the ones they have will survive infancy. Vietnam and Costa Rica really got their act together in this regard and built primary-health-care systems, which reduced mortality. More recently, Ethiopia and Rwanda have been doing the same. The Rwandan Health Minister put together 15,000 health centers staffed by two women each. Ghana, relative to its income, runs a pretty good health system, while Nigeria runs a poor one relative to its wealth. There’s quite a bit of variance in Africa.
Still, you say you’re optimistic about Africa overall.
Over the past half-decade, 7 out of the world’s 10 fastest-growing economies are in Africa. By the 1990s, life span had doubled in Africa and child mortality has dropped by a third compared to just a few years ago. Globalization has made copper and other minerals more valuable, and Ghana and Kenya have recently discovered mineral resources. The question is, Does the wealth that’s generated get used the right way to fund infrastructure and schools? African nations are still poorer than us, yes. But improvements in the human condition have laid the foundation for improvements in their entire societies.
Amid a polar winter in much of the U.S., a new report reinforces the long-term trend of global warming—and sets the stage for an even hotter 2014
As I write this, I can see snow falling heavier and heavier outside my office window in midtown Manhattan. Up to 14 inches (36 cm) are projected to accumulate by Wednesday morning, part of major winter storm that’s spreading from South Carolina to Maine. Temperatures are predicted to stay well below normal for the rest of the week, as we all remember what winter used to be like. In short, it’s going to be cold, snowy and brutal, and Americans might feel as if warm weather will never return.
But don’t worry—on a global climatic scale, the heat is still on. That’s the takeaway from the National Oceanic and Atmospheric Administration’s (NOAA) annual analysis of global climate data, which was released Tuesday. The red-hot numbers:
- 2013 ties with 2003 as the fourth-warmest year globally since records began in 1880.
- The annual global combined land and ocean surface temperatures was 58.12 degrees Fahrenheit (14.52 degrees Celsius), 1.12 degrees Fahrenheit above the 20th century average (the warmest year on record is 2010, which was 1.19 degrees Fahrenheit (0.66 Celsius) above the average.
- 2013 was the 37th consecutive year that the annual global temperature was above the average, which means that if you were born any year after 1976, you’ve never experienced a year when the global climate was average, let along cooler.
- Including 2013, 9 of the 10 warmest years on record have occurred in the 21st century, and just one year in the 20th century—1998—was warmer than 2013.
The NOAA report, coming out in the middle of a major snowstorm and during a U.S. winter that’s been marked by the polar vortex, is a reminder that climate isn’t about the day-to-day changes in the weather (Note: NASA came out with its own report on 2013, using a different calculating method than NOAA, and found 2013 to be slightly cooler, but still the seventh-warmest year on record). It’s about the very long-term, as Gavin Schmidt, the deputy director of NASA’s Goddard Institute for Space Studies in New York, said on a conference call with reporters Tuesday afternoon:
The long-term trends in climate are extremely robust. There is year-to-year variability. There is season-to-season variability. There are times such as today when we can have snow even in a globally warmed world but the long-term trends are very clear. They’re not going to disappear.
Not only is climate change a long-term phenomenon, it’s also a global one, though it’s easy to get lost in our weather. Case in point: the average temperature in the continental U.S. in December was 30.9 F (-0.6 C). That’s 2.0 F (1.1 C) below the 20th century average. That’s the 21st coldest winter on record for the U.S. You weren’t just a wimp—December really was chilly for much of the U.S.
But the globally the picture was very different. The worldwide average temperature in December was 55.15 F (12.84 C), which is 1.15 F (0.64 C) above the 20th century average. While the U.S. was shivering, on a global scale December 2013 was the third warmest December on record. That’s global warming.
And 2014, despite the snowy and chilly start in the U.S., could be even hotter. Scientists now say that an El Nino seems likely to develop later this year, which is likely to push temperatures up in 2014 and 2015, since El Nino years tend to be warmer. So enjoy the snow while you can—it will likely be a faint memory by time Americans are sweating in July.
Production has been booming for awhile, but last year American demand for the black stuff grew by 390,000 barrels a day
The oil production boom in the United States is old news, something we covered in a special section just a few months ago. Improved hydraulic fracturing and directional drilling has helped unlock vast new tight oil supplies, mostly in Texas and North Dakota. But I don’t think everyone has realized just how much boom is in this boom.
New numbers from the International Energy Agency (IEA) might change that. Crude oil production in the U.S. rose by 990,000 barrels a day (bbd) last year, a increase of 15% from the year before. That’s the fastest such absolute annual growth of any country in 20 years. And it’s not just production: The IEA reports that in 2013, U.S. demand for oil grew by 390,000 bbd, or about 2%, after years of decline. For the first time since 1999, U.S. demand for oil grew faster than China’s demand, which rose by 295,000 bbd, the weakest increase in six years. So not only is the U.S. producing a gusher of oil, but it’s also consuming more crude.
That increase in domestic demand could a good sign for the economy, if not for the environment. Growth in oil demand was mostly steady in the U.S. from the early 1980s on, before plateauing a couple of years before the financial crisis of 2008. Since then it’s mostly dropped. Average consumption in the U.S. was 18.8 million bbd between 2009 and 2012, compared to 205 million bbd between 2005 and 2008. Economic growth and energy demand have historically gone together—more businesses using more energy, more workers driving to the office—so last year’s unexpected increase in oil demand could mean the U.S. is rebounding, as Antoine Heff, head of oil market research at the IEA, told the Financial Times:
It is clear that the US economy is rebounding very strongly thanks to its energy supplies. Sometimes oil is a lagging indicator, but sometimes it is the opposite and shows that an economy is growing faster than thought.
According to the IEA, much of that growth has been in the petrochemical industry, which has taken advantage of burgeoning domestic oil supply. U.S. exports overall hit a record high in November, cutting the trade deficit to its lowest level since 2009. And much of that export growth came not from manufactured goods but from diesel and gasoline, with the U.S. exporting $13.3 billion worth of petrochemical products in November. With oil companies forbidden from exporting crude from the U.S.—though they’ve been lobbying lately to get that changed—refineries have taken up the slack, benefiting from the fact that domestic oil is often sold at a discount (they’ve also benefited from low natural gas prices, thanks to shale drilling). It’s not for nothing, as Mitchell Schnurman noted in the Dallas Morning News, that the oil capital of Houston led the nation in exports in 2012, ahead of the New York area.
But even if the U.S. economy does rebound—and boom times in the petrochemical industry don’t necessarily translate to the rest of the country—don’t expect the U.S. to go all the way back to its gas guzzling days. There are other reasons besides a declining economy that explain why U.S. oil demand fell so much over the past several years. Cars are now more fuel-efficient than ever, thanks to tougher fuel economy standards and growing consumer preferences for lighter, smaller cars and hybrids. But we’re also driving less. An analysis by Michael Sivak at the University of Michigan Transportation Research Institute found that 9.2% of U.S. households in 2012 were without a vehicle, compared to 8.7% in 2007. Vehicle miles traveled has largely plateaued over the last several years, indicating the U.S.—like other developed countries—may have reached something like “peak car.”
That’s arguable—the drop in the percentage of households with cars could well have more to do with high unemployment and slugging economic growth than anything else. But while the boom in domestic oil production has helped stabilize gas prices—a gallon cost an average of $3.32 a gallon in 2013, just a little more than in 2012—the days of cheap gas are almost certainly over. The future of oil demand is going to be in the developing world—especially China, where consumers bought over 20 million cars in 2013, compared to 15.6 million in the U.S. 2013 will likely turn out to be a blip in that epochal shift.
Scientists analyzing images from the Mars Opportunity Rover are flummoxed after a rock mysteriously appeared in the rover's field of vision last week
Scientists analyzing images from the Mars Opportunity Rover are flummoxed after a rock mysteriously appeared in the rover’s field of vision last week.
“It was a total surprise,” NASA scientist Steve Squyres told Discovery News. “We were like ‘wait a second, that wasn’t there before, it can’t be right. Oh my god! It wasn’t there before!’ We were absolutely startled.”
Some hypothesize the rock may have landed there after being flung skyward by a meteor that landed nearby, but the leading theory blames the rover itself for overturning a nearby rock with a quick, jittery wheel maneuver.
“You think of Mars as being a very static place and I don’t think there’s a smoking hole nearby so it’s not a bit of crater ejecta, I think it’s something that we did,” Squyres said. “We flung it.”
The Kepler Space telescope, which was recently given up for dead, will find a second life
When the Kepler space telescope malfunctioned last spring, it looked as though its incredibly successful planet-hunting mission might be over—and NASA made that sad fact official a few months later. To find planets around distant stars, Kepler needed to keep its gaze fixed unerringly on a single patch of sky, month after month, with no wavering. The breakdown of the second of its four reaction wheels, however, which had kept the satellite precisely aimed since it reached orbit in 2009, made it impossible to continue its work.
But while the original Kepler mission is kaput, engineers have found a way to return their spacecraft to the planet-hunting game—and to study such esoteric cosmic beasts as giant black holes, exploding stars and dark energy in the bargain. “The science,” says Kepler project scientist Steve Howell, “is much better than we thought possible last summer. We’re really, really excited.”
Kepler’s reincarnation, known as the K2 mission, still has to be approved by NASA headquarters, in a process known as Senior Review; the final decision probably won’t come until May. But if K2 doesn’t make the cut, it won’t be for lack of human ingenuity—at least on the part of the designers, who, the moment the spacecraft broke down, began thinking hard about what else it might be able to accomplish.
Maybe it could be used to search for asteroids, for example, or to look for stars exploding in the gigantic blasts known as supernovas. “We called for ideas from the scientific community,” says Kepler Deputy Project Manager Charlie Sobeck, “but also from the engineering community, asking how we could best point Kepler with just two reaction wheels.” They got scores of responses from both groups, and, says Sobeck, “came up with the most compelling mission we could.”
What the engineers realized was that they could improve Kepler’s stability by aligning it with the particles of solar wind that stream constantly from the Sun. “It’s like a rowboat pointing upstream,” says Sobeck. It’s not perfectly stable—the boat, or the spacecraft, will eventually swing around. But it takes only gentle adjustments to correct that drift, and the two remaining reaction wheels are powerful enough to make those tweaks.
Pointing upwind means Kepler can look only out in the direction of the ecliptic—the apparent path of the Sun through the sky during the year (it’s where the constellations of the Zodiac sit), though of course the telescope will always point directly away from the Sun. While the original Kepler field of view lies outside the ecliptic, there are plenty of stars, with plenty of planets to discover, in Kepler’s new, ever-changing field.
Not only that: most of Kepler’s earlier target stars were dim and distant; in the new field of view there will be plenty of bright, relatively nearby ones, which makes it easier to do followup studies of whatever planets the probe does find. That’s the rationale behind a newly approved mission known as the Transiting Exoplanet Survey Satellite, or TESS. But TESS won’t launch until 2017, so K2 could get a head start on that project.
K2 will also study the stars themselves—especially star clusters, important because they contain many stars of different types that are exactly the same age. That makes them perfect laboratories for understanding the stellar aging process. The Pleiades cluster, for example, familiar to even the most casual stargazer, will be smack in K2’s crosshairs.
At other times, Kepler will find itself pointing at fields of view containing tens of thousands of galaxies. Some of those galaxies will vary in brightness, as the black holes at their cores swallow meals of gas and belch out high-energy flashes of light; others will flare with the exploding stars known as supernovas. The latter are interesting all by themselves, but they’re also useful as signposts that gauge cosmic distances—signposts that first clued astronomers into the existence of the dark energy that pervades the universe.
(VIDEO: Phone Home: NASA’s Call Center)
In principle, K2 could track these supernovas from the first few hours after their initial explosion, which could help theorists figure out exactly how bright, and exactly how far away, they are. “The original Kepler mission actually saw some supernovas,” says Howell, and the observations were vastly better than anything ever seen from ground-based telescopes.
There’s no guarantee that K2 will pass NASA’s Senior Review, especially since the agency is also ruling on whether to continue funding projects involving the Hubble and Spitzer and other space observatories, so K2 has competition. Two years ago, however, Kepler was up for a mission extension against some of those other 800-lb. gorillas, and got the nod. “They could say no,” says Howell, “but we’re very hopeful.”
(SPACE PHOTOS: 45-Year-Old Footprints and More)
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Of all the questions surrounding a Jan. 9 chemical spill in West Virginia, this might be the most disturbing: How dangerous was the chemical? About 7,500 gal. (28,390 L) of 4-methylcyclohexane methanol (MCHM) seeped into the Elk River when a tank holding the coal-cleaning solvent ruptured. Three hundred thousand people were left without access to running water and were unable to use their faucets to drink, cook or bathe for five days.
No human health data exists on MCHM, just a single study on rats. That’s because MCHM is one of almost 62,000 chemicals that were grandfathered in when the Toxic Substances Control Act was passed in 1976.
How simple chemistry turned into biology has always been a mystery, but some smart people have some intriguing ideas
The odds that the universe is bursting with life seem to be getting better all the time. Astronomers recently announced that there could be an astonishing 20 billion Earthlike planets in the Milky Way—and that’s if you’re limiting the pool to planets orbiting stars like the Sun. If you add the small, reddish stars known as M-dwarfs, which also harbor planets, the number is even greater. Within our own Solar System, meanwhile, the evidence for a plausibly life-friendly ocean on Jupiter’s moon Europa is stronger than ever, and the Curiosity rover has confirmed that some kinds of bacteria could have thrived in Mars’s Gale Crater billions of years ago. On a more universal scale, scientists know for a fact that two of the essentials for life—water and carbon—can be found literally everywhere.
How abundant life actually is, however, hinges on one crucial factor: given the right conditions and the right raw materials, what is the mathematical likelihood that life will actually would arise? If it’s a 50-50 proposition, then given the vast amount of available real estate, biology would have to be popping up all over the place. But if it’s a one-in-a-trillion shot, we could indeed be all alone in the vastness of space. To date, despite more than a half-century of trying, nobody has managed to figure how life on Earth began. Without knowing the mechanism by which inanimate chemistry assembled and bestirred itself, admits Andrew Ellington, of the Center for Systems and Synthetic Biology at the University of Texas, Austin, “I can’t tell you what the probability is. It’s a chapter of the story that’s pretty much blank.”
Given that rather bleak-sounding assessment, it may be surprising to learn that Ellington is actually pretty upbeat. But that’s how he and two colleagues come across in a paper in the latest Science. The crucial step from nonliving stuff to a live cell is still a mystery, they acknowledge, but the number of pathways a mix of inanimate chemicals could have taken to reach the threshold of the living turns out to be many and varied. “It’s difficult to say exactly how things did occur,” says Ellington. “But there are many ways it could have occurred.
The first stab at answering the question came all the way back in the 1950s, when chemists Stanley Miller and Harold Urey passed an electrical spark through a beaker containing methane, ammonia, water vapor and hydrogen, thought at the time to represent Earth’s primordial atmosphere. When they looked inside, they found they’d created amino acids, the building blocks of proteins.
That experiment is now considered a dead end, since the atmosphere probably didn’t look like that after all, and also since the steps from amino acids to life turned out to be hellishly difficult to reproduce—so difficult that it’s never been done. But Ellington sees things differently. “It was a monster achievement,” he says, “and since then we’ve learned a truckload.”
Scientists have learned so much, in fact, that the number of places life might have begun has grown to include such disparate locations as the hydrothermal vents at the bottom of the ocean; beds of clay; the billowing clouds of gas emerging from volcanoes; and the spaces in between ice crystals.
The number of ideas about how the key step from organic chemicals to living organisms might have been taken has multiplied as well: there’s the “RNA world hypothesis” and the “lipid world hypothesis” and the “iron-sulfur world hypothesis” and more, all of them dependent on a particular set of chemical circumstances and a particular set of dynamics and all highly speculative.
Worse, however things played out, all evidence of the process has long since vanished: the very first cells have left no traces, and the environments that nurtured them have disappeared as well. The best scientists can hope to do is to create a proto-cell in the lab.
“Maybe when they do,” says Ellington, “we’ll all do a face-plant because it turns out to be so obvious in retrospect.” But even if they succeed, it will only prove that a manufactured cell could represent the earliest life forms, not that it actually does. “It will be a story about what we think might have happened, but it will still be a story.”
The story Ellington and his colleagues have been able to tell already, however, is a reason for optimism. We still don’t know the odds that life will arise under the right conditions. But the underlying biochemistry is abundantly, ubiquitously available—and it would take an awfully perverse universe to take things so far only to shut them down at the last moment.