Mammoths Died Out Because of Sudden Climate Change

The mighty megafauna of the last ice age, including the wooly mammoths, short-faced bears and cave lions, largely went extinct because of rapid climate-warming events, a new study finds.

During the unstable climate of the Late Pleistocene, about 60,000 to 12,000 years ago, abrupt climate spikes, called interstadials, increased temperatures between 7 and 29 degrees Fahrenheit (4 and 16 degrees Celsius) in a matter of decades. Large animals likely found it difficult to survive in these hot conditions, possibly because of the effects it had on their habitats and prey, the researchers said.

Interstadials “are known to have caused dramatic shifts in global rainfall and vegetation patterns,” the study’s first author Alan Cooper, director for the Australian Center for Ancient DNA at the University of Adelaide in Australia, said in a statement emailed to Live Science.

Temperature drops during the Late Pleistocene showed no association with animal extinctions, Cooper said. Instead, only the hot interstadial periods were associated with the large die-offs that hit populations (local events) and entire species of animals (global events), he said.

Ancient humans also played a role in the megafaunal extinction, albeit a smaller one, he said. By disrupting the animals’ environments, human societies and hunting parties likely made it harder for megafauna to migrate to new areas and to refill areas once populated by animals that had gone extinct, he said.

Extinction analysis

The study is the latest in a long string of research examining what caused megafauna, or animals weighing more than 99 pounds (45 kilograms), to die off during the Late Pleistocene.

George Cuvier, the French paleontologist who first recognized the mammoth and the giant ground sloth, started the speculation in 1796 when he suggested that giant biblical floods were to blame for the animals’ demise. The extinctions also baffled Charles Darwin after he encountered megafaunal remains in South America.

Since then, various studies have placed the bulk of responsibility on ice age humans, temperature swings and a perfect storm of events.

However, advances in examining ancient DNA and ancient climate allowed Cooper and his colleagues to get to the bottom of the issue.

They examined DNA from dozens of megafaunal species that lived during the Late Pleistocene, combing through more than 50,000 years of DNA records for extinction events. The ancient DNA not only told them about global extinction events, but also local population turnovers, which occur when a group of animals dies and another population of animals moves in to replace them.

They then compared the data on megafauna extinction with detailed records of severe climate events, which they gathered from Greenland ice cores and the sedimentary record of the Cariaco Basin off Venezuela.

“By combining these two records, we can place the climate and radiocarbon dating data on the same timescale, thereby allowing us to precisely align the dated fossils against climate,” Cooper said. “The high-resolution view we gained through this approach clearly showed a strong relationship between warming events and megafaunal extinctions.”

The findings also show that extinction events were staggered over time and space, likely because the interstadial warming events had different effects on different regions, Cooper said.

Modern connections

Earth’s climate is much more stable today than it was during the Late Pleistocene, making the world’s current warming trends a “major concern,” the researchers said.

“In many ways, the rise of atmospheric carbon dioxide levels and resulting warming effects are expected to have a similar rate of change to the onset of past interstadials, heralding another major phase of large mammal extinctions,” Cooper said.

In addition, humans have disrupted the habitats and surrounding areas of many wild animals, making it challenging for species to migrate or shift ranges to places where they would be better adapted to deal with climate change, he said.

Other researchers called the new study an important one.

It shows “that the extinction and population turnover of many megafauna was associated with rapid warming periods, rather than the last glacial maximum [when the ice sheets reached their maximum during the last glacial period] or Younger Dryas [a sudden, cold spell that happened when the Earth was starting to warm] as has previously been suggested,” said Eline Lorenzen, an assistant professor of paleogenetics at the University of Copenhagen in Denmark.

Read more at Discovery News

Hazy Atmosphere Reveals Pluto's Red Secret

NASA’s New Horizons spacecraft has given scientists their first hint about why Pluto has a reddish hue.

Looking back at Pluto seven hours after its historic July 14 flyby, New Horizons captured a striking view of the distant world backlit by the sun. Aesthetics aside, the image, which was released Friday, shows a surprisingly diffuse and structured layer of haze in Pluto’s atmosphere rising more than 100 miles off the surface -- five times higher than predicted by computer models.

Scientists believe methane in the atmosphere is being chemically processed by solar ultraviolet radiation, leading to the production of reddish colored hydrocarbons known as tholins that end up on Pluto’s surface.

“We think that is how Pluto’s surface got its reddish hue,” New Horizons scientist Michael Summers, with George Mason University in Fairfax, Va., told reporters during a teleconferenced press briefing.

Scientists don’t understand why Pluto’s skies are hazy and why the particles extend so far from the surface of the frozen world.

“It’s a mystery,” Summers said.

New Horizons also looked for an atmosphere on Charon, Pluto’s primary moon, but found none, a preliminary assessment shows.

“Charon has much less atmosphere than Pluto, if any. We don’t yet have the full spectral data set. We won’t have that until September,” said New Horizons lead scientist Alan Stern, with the Southwest Research Institute in Boulder, Colo.

Using radio waves blasted from NASA’s Deep Space Network, New Horizons was able to measure Pluto’s atmospheric pressure. At the surface, atmosphere pressure, which is a measure of the overall weight or mass of the atmosphere, turned out to be far less than it was just two years ago.

Pluto reached the closest point to the sun in its 248-year long orbit in 1989. Scientists suspect the atmosphere could be freezing out as Pluto careens back out into the Kuiper Belt beyond Neptune.

Newly released close-ups of Pluto’s surface showed additional signs of geologically recent activity, including nitrogen ice flows.

“You can actually see the ice going around what look to be barrier islands,” said New Horizons scientist William McKinnon, with Washington University in St. Louis.

In the northern region of Pluto’s Sputnik Planum, swirl-shaped patterns of light and dark suggest that a surface layer of exotic ices has flowed around obstacles and into depressions, much like glaciers on Earth.

The ice flows are located in a Texas-sized piece of real estate, known as Sputnik Planum and located in the western side of Pluto’s heart-shaped bright region.

“We’ve only seen surfaces like this on active worlds like Earth and Mars,” John Spencer, with the Southwest Research Institute, added in a statement.

Initial analysis of materials on the surface of Sputnik Planum show it is flush with nitrogen, carbon monoxide and methane ices.

Read more at Discovery News

Assembly of galaxies in the early universe witnessed for the first time

When the first galaxies started to form a few hundred million years after the Big Bang, the Universe was full of a fog of hydrogen gas. But as more and more brilliant sources -- both stars and quasars powered by huge black holes -- started to shine they cleared away the mist and made the Universe transparent to ultraviolet light [1]. Astronomers call this the epoch of reionisation, but little is known about these first galaxies, and up to now they have just been seen as very faint blobs. But now new observations using the power of ALMA are starting to change this.

A team of astronomers led by Roberto Maiolino (Cavendish Laboratory and Kavli Institute for Cosmology, University of Cambridge , United Kingdom) trained ALMA on galaxies that were known to be seen only about 800 million years after the Big Bang [2]. The astronomers were not looking for the light from stars, but instead for the faint glow of ionised carbon [3] coming from the clouds of gas from which the stars were forming. They wanted to study the interaction between a young generation of stars and the cold clumps that were assembling into these first galaxies.

They were also not looking for the extremely brilliant rare objects -- such as quasars and galaxies with very high rates of star formation -- that had been seen up to now. Instead they concentrated on rather less dramatic, but much more common, galaxies that reionised the Universe and went on to turn into the bulk of the galaxies that we see around us now.

From one of the galaxies -- given the label BDF 3299 -- ALMA could pick up a faint but clear signal from the glowing carbon. However, this glow wasn't coming from the centre of the galaxy, but rather from one side.

Co-author Andrea Ferrara (Scuola Normale Superiore, Pisa, Italy) explains the significance of the new findings: "This is the most distant detection ever of this kind of emission from a 'normal' galaxy, seen less than one billion years after the Big Bang. It gives us the opportunity to watch the build-up of the first galaxies. For the first time we are seeing early galaxies not merely as tiny blobs, but as objects with internal structure!"

The astronomers think that the off-centre location of the glow is because the central clouds are being disrupted by the harsh environment created by the newly formed stars -- both their intense radiation and the effects of supernova explosions -- while the carbon glow is tracing fresh cold gas that is being accreted from the intergalactic medium.

By combining the new ALMA observations with computer simulations, it has been possible to understand in detail key processes occurring within the first galaxies. The effects of the radiation from stars, the survival of molecular clouds, the escape of ionising radiation and the complex structure of the interstellar medium can now be calculated and compared with observation. BDF 3299 is likely to be a typical example of the galaxies responsible for reionisation.

"We have been trying to understand the interstellar medium and the formation of the reionisation sources for many years. Finally to be able to test predictions and hypotheses on real data from ALMA is an exciting moment and opens up a new set of questions.This type of observation will clarify many of the thorny problems we have with the formation of the first stars and galaxies in the Universe," adds Andrea Ferrara.

Read more at Science Daily

Why Can't We Forecast Night Thunderstorms Better?

If you live in the middle of the country, you've probably woken to booming thunder and flashing lightning at least once this summer. If it seems like thunderstorms happen more at night, it's because they do.

What scientists are just beginning to figure out, though, is why. This summer, a major government-sponsored field project called PECAN (Plains Elevated Convection At Night) has gathered data that researchers say will lead to breakthroughs in understanding nighttime storms.

"We already know we have the data we need. We're going to be able to analyze the data and map windfields and temperature and moisture, which will allow us to understand it to give forecasters a much better idea," said Conrad Ziegler, a research meteorologist at the National Severe Storms Laboratory (NSSL) and the study's principal scientist.

Forecasters can more accurately predict what storms will do in the daytime, largely because the air near the earth's surface in the daytime is fairly representative of what's above it, allowing surface-based measurements such as radar to predict when a storm's going to stir up.

"When the sun goes down it gets interesting," Ziegler said.

During the day, the sun heats the ground and the warm air rises and mixes with the air above it. But when the sun goes down, all bets are off. As the surface air cools, it doesn't mix much, if at all, with the air above it, rendering surface measurements unreliable at predicting what's going on in the atmosphere.

For decades, mobile radar, ground-based weather stations, and weather balloons (deployed at a rate of once an hour at the most) have been used to observe storm systems. But in order to fully understand how the environment might affect the storm after sundown, more frequent readings are needed at higher points in the lower atmosphere.

At the moment, forecasters can see systems developing, but "the challenge is knowing when they're going to become severe with hail or strong winds or a tornado," said NSSL scientist Dave Turner, who was in charge of deploying the equipment used in PECAN. "We don't understand nighttime storms well enough, so computers don't model it. I don't think we have the right instrumentation."

For the PECAN study, scientists and graduate students spent six weeks this summer using state-of-the-art equipment in order to capture as much data from as many storms as possible, focusing on large systems of nighttime storms called Mesoscale Convective Systems that often produce severe weather. Turner set up 10 Infrared and microwave devices that provided temperature, humidity, and wind profiles about every five minutes, including four that could be moved around.

"We certainly saw many examples of a rapidly evolving atmosphere," he said, noting that they went on over 30 storm-tracking missions.

In many cases, the storms followed the pattern the scientists and students predicted, but in some cases what happened "wasn't anywhere close" to what they had expected, Turner said.

Read more at Discovery News

Rotting Fungus Creates Beautiful, Glistening 'Hair Ice'

A century-long puzzle over how delicate strands of glistening ice burst through rotting tree branches, like heads of hair, is closer to being solved.

The strands, called “hair ice,” exist only when cold-tolerant fungi are present, and scientists now understand how the fungi can stimulate ice growth.

Alfred Wegener, famous for his continental drift theory, first identified and studied hair ice in 1918. At the time, he suspected the ice formation was linked to the presence of mycelium — the roots of a fungus that live on rotting wood and absorb nutrients, forming a pale, white, cobweb-like coating. However, it wasn’t until about 90 years later that researchers found evidence that the fungal roots were vital precursors to hair ice. After treating mycelium-covered wood with a fungicide or dipping it in scalding water, hair ice didn’t grow, they found.

“The same amount of ice is produced on wood with or without fungal activity, but without this activity, the ice forms a crustlike structure,” Christian Mätzler, a co-author of the study and professor emeritus at the Institute of Applied Physics at the University of Bern in Switzerland, said in a statement.

The fungus helps the ice grow into thin hairs with diameters of just 0.01 millimeters (0.0004 inches), and helps to keep the strands in this shape over several hours at temperatures close to 32 degrees Fahrenheit (0 degrees Celsius), he added.

Researchers blamed the century-long delayed explanation for how hair ice grows on its ephemeral nature and northern range — the glimmering threads grow predominately at latitudes between 45 and 55 degrees north through countries including Canada, France, Germany, India, Ireland, the Netherlands, Russia, Scotland, Slovenia, Sweden, Switzerland, the United States and Wales.

“Hair ice grows mostly during the night and melts again when the sun rises,” said Gisela Preuß, a biologist at the Wiedtal-Gymnasium in Neustadt, Germany, who captured some of the hair-ice photos for the new study. “It’s invisible in the snow and inconspicuous in hoarfrost.”

Hunting for hair ice

“When we saw hair ice for the first time on a forest walk, we were surprised by its beauty,” Mätzler said. Although the hair ice typically melts the same day it forms, if the temperature stays below the freezing point and the air is humid, “it can last longer, but then it fades away,” Preuß told Live Science in an email.

In the new study, Preuß examined samples of dead wood that bore hair ice from the winters of 2012, 2013 and 2014 in forests near Brachbach in western Germany. She looked at the wood pieces under a microscope and found 11 different species of fungi. One species — Exidiopsis effuse — appeared in every sample.

“Similar ice formations are known from soil and dead stalks of some plants, but up to now, there is no hint the presence of a fungus in these cases,” Preuß said.

From rotting wood to hair ice

The researchers also analyzed the melted hair ice and found fragments of the organic compounds lignin and tannin. Lignin, which is found in vascular plants including land plants like mosses and conifers, makes up about 20 to 30 percent of dry wood and helps give wood its hardness and resistance to rotting.Tannin also occurs widely in vascular plants, and protect plants from herbivories, who dislike its astringent taste.

However, certain fungi and bacteria can secrete the enzyme lignase and break down the lignin, causing rot with moist, soft and spongy bark that looks white or yellow. White rot can enhance the fungi’s effects — the brightness of hair ice on wood increases as the wood decomposes, the researchers found, because the decomposed wood is brighter.

Fungus also acts as a hairspray by shaping the fragile ice hairs and keeping the strands in place, while lignin likely prevents recrystallization, which is the conversion of small ice crystals to bigger ones.

The hair ice is also influenced by the structure of the wood from which it radiates, the new study revealed. Tufts can grow outward from a branch, forming a center part much like human hair and can extend straight or curl back toward the branch. The latter radial growth pattern is more common and seems to be an extension of the natural rays that radiate in wood. All the strands grow 10,000 times longer than they are thick.

The researchers also found that the root of the hair ice — called a crystallization nucleus — is likely composed of lignin and tannin. When the air temperature drops sufficiently, water freezes into crystallization nuclei on the wood. Then, the nuclei create a passage for water to seep out of the pores of the wood and extend into ice hairs.

Read more at Discovery News

The Barnacle That Invades Crabs in a Not OK Way

The most miserable rainbow on Earth. That's a hermit crab with a rhizocephalan parasite, which comes in a lovely shade of yellow.

Crabs get a bad rap. After all, people who are into cheerfulness call me “crabby” all the time. But let’s cut them some slack (the crabs, not the cheerful people—forget them), because a lot of these critters could be going through some stuff. And by stuff I mean what has to be one of the most disturbing and wildly complex parasitizations in the animal kingdom.

So the rhizocephalans are these species of barnacle, and unlike most barnacles, they aren’t content living life stuck to rocks. Indeed, they look nothing like barnacles. Well, they start out as regular barnacle-ish larvae, shaped like an oval, but that’s where the similarities end. Instead of developing into your classical shelled variety, they invade the bodies of various crab species. And not as mere tiny hitchhikers: After penetrating a crab’s shell, a rhizocephalan grows as meandering roots throughout its victim’s flesh, sometimes reaching nearly every part of its body.

And then things start getting weird.

That mass on the lower bit of the crab’s abdomen is a parasitic barnacle. The other bits are its legs and claws, but you probably already knew that.

Like a Tree, Only It Grows Inside You and Instead of Drinking Water It Drinks Your Bodily Fluids

Life for a rhizo begins as an aforementioned larva, which is tasked with the seemingly impossible mission of not only finding the right species of crab (they tend to be able to infect just one type—that is, they’re highly “host-specific”), but somehow landing on it in the vastness of the sea. Rhizo babies appear in huge numbers, though, so by pure chance a few are bound to find their target. The rest—well, points for trying.

When one lands on a crab, it makes its way to one of the host’s many sensory hairs, known as setae, where the carapace is the weakest. Here the rhizo secretes a cement to anchor itself, just as a typical barnacle would. Next “it forms a so-called stylet, which is a hollow structure,” says Henrik Glenner of Norway’s University of Bergen. “It’s almost arrow-shaped, and with this it penetrates the cuticle of the host.”

A rhizo larva in its days of relative innocence. Ah, to be young again and not torturing crabs.

With this syringe, the rhizo injects cells of itself into the crab’s hemolymph, the invertebrate equivalent of blood. And you know how bad a sinus infection feels? Well, the rhizo ends up in the hemolymph sinuses, much to the chagrin of the crab. It’s here where it starts to grow as roots, which have a covering that somehow protects them from a potential immune response as they work their way through the host. They’ll soak up massive amounts of nutrients from the crab, and the roots can end up pretty much anywhere, even in the claws.

All the while, the crab is still miraculously growing, periodically shedding its exoskeleton. But eventually it stops, likely because the rhizo is appropriating too much of its nutrients. It’s at this point that the parasite enters its next stage: sexy time.

The Merits of Being Pretty Much Just a Testicle

Because the crab is no longer molting its exoskeleton away, the rhizo can now extend itself out of the host, forming a mass on the crab’s abdomen. “The funny thing about this is that this sac-like structure, the externa, is situated exactly where an adult female crab would have its egg mass,” says Glenner. “And we don’t know what the mechanism is, but the host considers the parasite as a part of itself.” The crab even takes care to groom and ventilate the sac, full of the rhizo’s eggs. (If the rhizo has infected a male crab, the host will actually start transforming morphologically, widening its abdomen to more closely resemble a female. This serves as better protection for the sac: If it grows on a wider abdomen, it won’t overflow past the edge of the carapace.)

All the more incredible, the rhizo is pulling this all off without a brain of its own and only the remnants of a nervous system. And the commandeering doesn’t end at the crab caring for the parasite. Somehow, the rhizo directs the crab away from the general crustacean population into deeper waters, thus avoiding feeding competition with healthy crabs. Non-parasitized gravid (that is, preggers) females do this with them, since they’ll find better protection from their enemies in the depths.

Another parasitized crab. It too has “legs.”

Now, it’s only female rhizos that infect crabs. Dwarf males look much like the larval form, and must somehow find not only a specific species of crab, but a specific species of crab that’s been invaded by a female. And that female has to be a virgin. The search, as you might expect, can be rather frustrating.

But should a male find a virgin female, he inserts himself into receptacles in her sac-like structure. “There the male changes form completely and becomes just a mass of cells,” says Glenner. “And actually it becomes a functional testicle, nothing more, and it’s nursed by the female. Then they are united for life.” Again and again, the male produces sperm to fertilize her eggs.

The eggs will hatch right inside the female, and when she’s ready to release the larvae, she gets an assist from her host. Your regular unparasitized female crabs will raise themselves up and shake their abdomens to disperse their eggs, and so too do infected crabs shimmy as the rhizo pumps out its larvae, boosting them into the water column. And off they go to infect still more crabs.

As a final insult, during all of this the crab itself cannot reproduce, for the rhizo has sterilized it. A lot of parasites do this—energy that the host isn’t putting toward reproduction can instead go to the parasite. The rhizo may pull this off with some kind of chemical, or it may just be a matter of exhaustion for the crab. Remember that all this time the parasite has been sapping it of nutrients, so it could be that the crab has gone into dire survival mode, and reproduction is the first thing that goes.

Read more at Wired Science

Climate Change, Human Hunger Erased Ice Age Animals

Woolly mammoths, saber-tooth tigers, giant sloths and other large animals from the last Ice Age became extinct due to rapid climate change and human-related causes, finds new research.

The abrupt climate warming that had such a negative impact on these animals is similar to the rapid man-made climate change that’s occurring today, according to the study, published in the journal Science.

“This abrupt warming had a profound impact on climate that caused marked shifts in global rainfall and vegetation patterns,” co-author Alan Cooper of the University of Adelaide and the Australian Center for Ancient DNA said in a press release.

He continued, “Even without the presence of humans we saw mass extinctions. When you add the modern addition of human pressures and fragmenting of the environment to the rapid changes brought by global warming, it raises serious concerns about the future of our environment.”

In short, many animals today could soon go the way of mammoths. That march to extinction already seems to be underway for many large mammals, such as the Javan rhino and the Cross River gorilla, which have experienced worrisome population drops over the past recent decades.

As for the prehistoric animals, which were the mega fauna of their time, the researchers compared data on these large animals’ DNA with radiocarbon measurements covering the past 56,000 years. Previously, when looking at the DNA information alone, the scientists detected a pattern. It showed that large species started to quickly bite the proverbial dust around 10,000–11,000 years ago.

At first they thought the extinctions were related to intense cold snaps. Two breakthroughs changed that view. First, the scientists were able to obtain more DNA from fossils in museum specimen collections. Second, carbon dating and understanding of temperature records have vastly improved over the years, permitting better resolution through time.

Read more at Discovery News

Mounting Threat to Galapagos From 'El Nino'

The Galapagos Islands, celebrated for their breathtaking biodiversity, could face a major threat from "El Nino," the weather system known to wreak havoc every few years.

The archipelago sustains a vast variety of plant and animal life, and has been recognized as a UNESCO World Heritage Site.

But the fragile Galapagos ecosystem may prove no match for the strong winds, heavy rains and warmer than usual ocean currents that accompany El Nino.

The dangers posed by those climatic changes are particularly acute for marine iguanas -- reptiles found only on the Galapagos -- which live on land but get their food from the ocean.

"Marine iguanas feed only on algae," Eduardo Espinoza, 46, director of marine research at Galapagos National Park, explained to AFP.

"During times of El Nino, these algae may be scarce and many begin to die," Espinoza said.

"El Nino" refers to the abnormal warming of surface waters in the tropical sections of the Pacific Ocean every three to five years.

Climatologists began observing the most recent ElNino several months ago, and fear that because of global warming, the phenomenon will hit the Galapagos with increasing frequency and greater destructive potential in coming years.

Read more at Discovery News

Kepler Discovers Earth's Older Sister

NASA’s Kepler space telescope has found the closest match yet to a world that is similarly sized to Earth and circling a sun-like star at the right distance for liquid surface water, a condition believed to be necessary for life, scientists said Thursday.

The newly found world, called Kepler-452b, is located about 1,400 light-years away in the constellation Cygnus.

“In my mind, this is the closet thing we have to another planet like the Earth,” Jon Jenkins, head of Kepler data analysis at NASA's Ames Research Center in Moffett Field, Calif., told reporters on a conference call Thursday.

Kepler-452b is about 60 percent wider than Earth and estimated to have five times the mass, making it most likely a rocky world. It circles a G-type star very much like the sun, but estimated to be closer to 6 billion years old, compared to the 4.6-billion-year age of the solar system.

“That’s a considerable opportunity for life to arise, should all the necessary ingredients and conditions for life exist on this planet,” Jenkins said.

“It’s simply awe-inspiring to consider that this planet has spent 6 billion years in the habitable zone of its star,” Jenkins said. “That’s considerable time and opportunity for life to arise somewhere on its surface, or in its oceans, should all the necessary ingredients and conditions for life exist on this planet.”

Kepler-452b orbits its parent star every 385 days, so it is located just about 5 percent farther away from the star than Earth circles the sun. The star’s age means it’s about 10 percent bigger and 20 percent brighter than the sun, Jenkins said.

If Kepler-452b is rocky, scientists expect it would be about five times more massive than Earth and twice Earth’s surface gravity. It would have a thicker, cloudier atmosphere and most likely active volcanoes, Jenkins added.

Read more at Discovery News

Adventure Science Enters the Space Age

Science is an intellectual adventure. Sometimes it is also a physical adventure.

The recent flyby of Pluto and its moon Charon by NASA’s New Horizons mission, for example, has reconnoitered new reaches of space for science, and it has expanded our knowledge of the outer solar system. The mission will continue through the Kuiper Belt, investigating a realm far from immediate human experience.

Yet when some adventurous soul does travel as far as Pluto, perhaps to set a record, or merely for bragging rights, it will be a day far more memorable -- and perhaps more scientifically valuable -- than New Horizon’s feat.

Sometimes adventures not intended as anything more than personal excitement or narrow competition have resulted in surprising discoveries. In earlier eras, adventure was often necessary to advance science. Robert Peary’s expedition to the North Pole in 1909 and Roald Amundsen’s expedition to the South Pole in 1911 exemplify the spirit of adventure science, but they had many predecessors.

Early modern mariners literally sailed off the map, and their stories are now an essential piece of human culture and history. Later, the French Geodesic Mission to the equator of 1735-1739 was recounted in the 1748 book Relación histórica del viaje a la América meridional by Jorge Juan and Antonio de Ulloa, which is as much about the adventure as about the science of the expedition.

The accounts of the French Geodesic Mission partly inspired Alexander von Humboldt’s 1799-1804 travels in South America. Humboldt himself became one of the most famous Europeans on the 19th century and inspired the academic field of biogeography. Darwin’s years on board the Beagle opened his eyes to the diversity of life, and continued to serve as an inspiration for decades after his return. We’re told his later theories even had some impact on the scientific community.

Now the Earth has been largely explored, and adventures in exploration become increasingly more contrived as the world is known in increasingly fine detail. The adventure science of Humboldt, Darwin, Peary, and Amundsen no longer holds its esteemed position either in popular imagination or in serious science.

Wealthy, idiosyncratic elites like James Cameron still spark occasional headlines, yet the era is gone in which adventurers could make a disproportionate contribution to science by going where no human being had previously set foot, or where no trained scientific observer had recorded their experiences. Researchers willing to sleep in the rough and forego the comforts of home still make discoveries in Earth’s jungles, deserts, deeps and tundras, yet their work remains bound to restrictive grants and professionalized disciplines.

Not only has the world been explored, but the conditions of science have changed. “Big” science now makes headlines. Scientific research papers in fields like particle physics and genetics might boast lists of up to three thousand co-authors or more. The scientific instruments necessary to conduct cutting edge experiments in particle physics, for instance, cost billions of dollars and take years or decades for construction. Once constructed, they must be maintained and updated at further expense.

Thomas Edison was among the first to demonstrate the power of this kind of systematic research, yet such expenses can only be borne by large, well-financed organizations. This kind of institutionalization comes with a battery of social as well as scientific constraints. In this context, the individual (to say nothing of the adventurer) experiences little scope for innovation or eureka moments.

The great age of adventure science has given way to an age of big science, but there may yet be a role for adventure science in the future. Adventure science is a considerable departure from “big science,” and the renewal of adventure science in our future will mean renewed opportunities for individuals to contribute to science in a way that individuals cannot contribute today.

Once the costs of human spaceflight are reduced to a point that spaceflight can become routine, the greater part of humanity will continue to prefer the comforts of Earth, but some individuals, drawn by a need to explore, will strike out into the cosmos. What they learn may accrue to us all. A single geologist walking the surface of Mars with a shovel and a rock hammer could make discoveries of great significance.

The space age of adventure science will not remake civilization. We will not, for example, go into space in order to transmit energy down to Earth. By the time we have a robust and routine presence in space we will already have solved our energy problems on Earth. The terrestrial power grid is already in the midst of being reconfigured for sustainability, and increasingly sophisticated technology will allow us to continue to live well while no longer fouling our own nest (one of the authors of the present article has argued this position in The Conversion of the Terrestrial Power Grid and The Human Future in Space).

And we will not go into space in order to relieve the population pressure on Earth. Buckminster Fuller once observed that, “The entire population of the earth could live compactly on a properly designed Haiti and comfortably on the British Isles.” We are not yet at the point of a global Hong Kong, yet urbanization continues along with improved efficiencies that allow greater densities to live in comfort. And increasing these population destinies will not continue indefinitely. If demographics is destiny, our destiny today is likely that of peak population at some time in the coming century, followed by demographic contraction.

Read more at Discovery News