How Living Inside Biosphere 2 Changed These Scientists' Lives

© CDO courtesy of the University of Arizona
© CDO courtesy of the University of Arizona

Taber MacCallum and Jane Poynter witnessed the most affecting solar eclipse of their lives in 1992. That's because as they watched the Sun disappear behind the Moon’s shadow, they were also watching their oxygen supplies slipping away.

At the time, they and their six teammates were sealed inside Biosphere 2, a 91-foot-tall, 3.14-acre experimental complex outside Tucson, Arizona. “We were all just glued to the monitors,” MacCallum recalls, “because you can see when the Sun was hidden away by the Moon, for that half hour period, the CO2 started going up. The oxygen started going down. You could see the actual, palpable effect.”

Without the Sun, the plants around them had stopped photosynthesizing and producing oxygen. Earth’s atmosphere is so huge that half an hour of this during a solar eclipse doesn’t have a noticeable effect. But inside an atmosphere 19 trillion times smaller than Earth’s, MacCallum and Poynter noticed.

“It's very hard on the Earth to get that tight a visceral connection between your behavior and the environment,” MacCallum says.

Today, the imposing white dome of Biosphere 2 still rises above the Arizona desert like a cross between a greenhouse and the Taj Mahal. Now, it’s a research station maintained by the University of Arizona where researchers study Earth processes, global environmental change, weathering, landscape evolution, and the effect of drought on rainforests, among many projects. Because of its systems and size, scientists can do controlled experimentation at an unprecedented scale in Biosphere 2.

Another view of Biosphere 2. Image credit: © CDO courtesy of the University of Arizona

 
MacCallum and Poynter returned to Biosphere 2 in May 2016 for the One Young World Environmental Summit to speak to young environmental leaders from around the world. But in the early 1990s, they and six others were sealed inside it for two years and 20 minutes, from September 26, 1991 to September 26, 1993, in a life-changing experiment that was equal parts humility and hubris—both shortsighted and ahead of its time.

“The big questions of the two-year mission,” says MacCallum, were, “Can we build artificial biospheres? Can these be objects of science? Can we learn from them?”

We could and did. As a result of their voluntary containment, we learned how to seal a giant building so that it loses less air than the International Space Station, manage damaged coral reefs, feed eight people on a half-acre of land, and recycle water and human waste in a closed system, among other things.

The structure itself, built from 1987 to 1991, is a technological marvel even today. The idea was to build a miniaturized biosphere completely separated from Earth, see if humans could live inside it, and see how they affected the animals and plants around them and vice versa. (Why call it Biosphere 2? Because Earth is Biosphere 1.) It’s roughly as tightly sealed as the space station and separated from the soil around it by a 500-ton steel liner.

In the early '90s, when the mission started, the ideas that humans were causing climate change or even that Earth was a biosphere at all were much less accepted than they are today. “When we started this project, I was spelling the word ‘biosphere’ down the phone,” says MacCallum.

Much the way a botanical garden's conservatory is, Biosphere 2’s glass-walled domes and pyramids were filled with different biomes: rainforest, ocean (with a coral reef), savannah, desert, mangrove swamp, and agricultural fields in which the team grew all their crops. They ate so many sweet potatoes that Poynter turned orange, but their world also included domestic animals: goats (their only dairy source), chickens, pigs, and tilapia. They had only enough coffee plants to make one cup of coffee per person every few weeks.

The desert biome in Biosphere 2. Image credit: © CDO courtesy of the University of Arizona

 
Problems quickly developed. The coral reef became overgrown with algae. Most of the pollinating insects died. A bush baby in the rainforest biome got into the wiring and was electrocuted. Each of the crew members had a primary job: Poynter was in charge of the farm and farm equipment, and MacCallum was in charge of the analytical chemistry lab inside Biosphere 2. The crew had to do all their research, farming, and experiments while hungry because they weren’t getting enough calories.

More dangerous was the decline in oxygen. That night in 1992, their oxygen levels dipped temporarily, but overall their oxygen levels declined from 20.9 percent to 14.5 percent. (Any environment below 19.5 percent oxygen is defined as oxygen-deficient by the Occupational Safety and Health Administration, or OSHA.) The low oxygen made them lethargic. For months they couldn’t sleep properly because it gave them sleep apnea. Scientists were monitoring them and communicating with them from the outside, and finally in August 1993, just a month before the crew left Biosphere 2, they decided to start pumping in oxygen.

Taber MacCallum tests air conditions in Biosphere 2. Image credit: © CDO courtesy of the University of Arizona

 
Later, scientists figured out that the culprits were microbes proliferating in the Biosphere’s compost-rich soil, combined with the building’s concrete. The microbes themselves were not harmful, but they converted oxygen into carbon dioxide, which then reacted with the building’s concrete to form calcium carbonate and irreversibly remove oxygen molecules from the Biosphere's atmosphere.

Still, looking back more than two decades years later, MacCallum and Poynter view the experiment as a success. Its initial science findings have been developed on in the years since—the University of Arizona has owned the facility since 2007—and its research focus remains as big picture as it ever was: global environmental change.

Beyond the science, even just seeing Biosphere 2 could change people’s perspectives. Poynter recalls getting an email while she was inside Biosphere 2 from a man who walked around the perimeter of the structure as part of the monitoring effort, who said, “'I get it now, because I walked around Biosphere 2, this miniature version of planet Earth, and it smacked me in the face: you guys only have what you have in there, and you have nothing else.'”

“That is fundamentally the message: that it's finite,” Poynter says. “And also very resilient.”

When after two years they finally emerged, Poynter had lost virtually all the enzymes to digest meat from eating so little of it. Nevertheless, she says, “Physically, we were in pretty decent shape. I had spent every day farming, so I was pretty strong.”

Jane Poynter checks on the goats in Biosphere 2. Image credit: © CDO courtesy of the University of Arizona

 
Still, it was a huge change. “The experience of coming out of Biosphere 2 was amazing in that it was like being reborn into this world and seeing it with fresh eyes,” she recalls. That night they had a big party with friends they hadn’t seen in two years. “And then the next morning there was this giant pile of garbage. It was this stark reminder of this consumable world that we live in.”

Poynter and MacCallum, who were dating when they entered Biosphere 2, married nine months after leaving it. Together with three others, they formed Paragon Space Development Corporation. Over the years, they developed a range of aerospace technology, including temperature control and life support systems for NASA and SpaceX that could be used to support people on the Moon or on Mars.

Their current company, World View Enterprises, spun out of Paragon in 2013. Key staff include chief scientist Alan Stern, head of the New Horizons mission to Pluto, and astronaut Mark Kelly (twin brother of astronaut Scott Kelly), who is the director of flight crew operations. World View sends uncrewed vehicles high up in the near-space stratosphere to research weather and other phenomena, and aims to one day bring people up to where the sky is black, the Earth looks curved, and it’s visibly clear that Earth is the home we share.

The curvature of the Earth as captured by a World View craft. Image credit: World View

 
It's that big-picture view that Poynter and MacCallum want to share with others. After talking with astronauts, they think that the “overview effect” astronauts feel when seeing the Earth from space is not unlike what they felt in Biosphere 2. Like Poynter and MacCallum, astronauts describe feeling deeply moved by the experience to do something to help Earth and its people.

Poynter says the company’s technology is proprietary and has to do with buoyancy control. “The basis of it is our ability to do very accurate altitude control,” she says, which allows their vehicles to take advantage of prevailing winds at different altitudes to travel exactly where they want.

World View Enterprises is particularly interested in taking leaders and influencers up to the stratosphere. Because you can’t just lock world leaders inside a biosphere in the desert for two years to give them the insight that Poynter and MacCallum know so deeply: We, as humans, are fully connected to and dependent on our environment.

“In the biosphere," Poynter says, "I really fell in love with the Earth."

Could Gigantic Coconut Crabs Have Played a Part in Amelia Earhart’s Mysterious Disappearance? At Least One Scientist Thinks So

Getty Images
Getty Images

Amelia Earhart's disappearance during her attempt to fly around the world has captivated historians and conspiracy theorists for more than 80 years. One organization is now suggesting that her fate may have been sealed by giant crabs.

The International Group for Historic Aircraft Recovery (TIGHAR) believes that Amelia Earhart and navigator Fred Noonan may have landed their plane on Nikumaroro Island when they couldn't find their target, Howland Island, and that Nikumaroro's endemic crustaceans may have played a part in the ensuing mystery.

According to National Geographic, there are several clues supporting TIGHAR's theory. The large reef that hugs Nikumaroro’s coast makes it conducive to emergency aircraft landings. In 1940—just three years after Earhart’s disappearance—British colonists found 13 human bones beneath a ren tree on the island and shipped them to Fiji, where they were lost. The colony's administrator, Gerald Gallagher, sent a telegram back to England positing that it was Earhart’s skeleton. Then, in 2001, researchers uncovered U.S.-made artifacts around the ren tree including a jackknife, a woman’s compact, a zipper, and glass jars. The plot thickened even further in 2017, when four forensic bone-sniffing dogs all indicated that a human had indeed died at the site, though excavators failed to dig up any more evidence.

If those 13 bones beneath the ren tree did belong to the unfortunate castaway, where are the rest of her remains? Tom King, TIGHAR’s former chief archaeologist, thinks that coconut crabs can answer that question.

Nikumaroro is home to thousands of the colossal creatures, which can grow to a terrifying 3 feet across and weigh 9 pounds. They’re sometimes called robber crabs because of their penchant for absconding with objects that smell like food, and they’ll eat practically anything—coconuts, fruit, birds, rodents, other crabs, their own discarded body parts, and carrion.

It’s not unreasonable, then, to think that coconut crabs may have feasted on Earhart’s corpse and then taken her bones home with them. In one experiment to test the theory, TIGHAR researchers deposited a pig carcass on the island and filmed the aftermath. With the help of small strawberry hermit crabs, coconut crabs stripped the pig down to the bone in two weeks. After a year, some of the bones had been dragged 60 feet from the carcass’s original location, and some were never recovered at all.

King believes Earhart’s missing 193 bones could be hidden in the burrows of various coconut crabs. As in the pig experiment, crabs may have scattered some of Earhart’s bones dozens of feet away, but maybe not all of them—after all, the forensic dogs smelled bones near the ren tree that haven’t yet been located. Right now, TIGHAR is working with the Canine Forensics Foundation to further explore the area.

While we wait for more answers, dive into these other theories about Earhart’s disappearance.

[h/t National Geographic]

10 Juicy Facts About Leeches

Ian Cook
Ian Cook

Leeches get a bad rap, but they’re actually pretty cool once you get to know them—and we're finding out more about them, even today. Recently, a team led by Anna Phillips, curator of parasitic worms at the Smithsonian National Museum of Natural History, discovered a new species of medicinal leech (pictured above) in a Maryland swamp. We asked parasite expert and curator at the American Museum of Natural History Mark E. Siddall to share some surprising facts about the worms we love to hate. 

1. Not all leeches suck blood.

Hematophagous, or blood-feeding, species are only one type of leech. “The vast majority of species are [hematophagous],” Siddall tells Mental Floss, “but it depends on the environment. In North America, there are probably more freshwater leeches that don’t feed on blood than there are blood-feeders.” And even among the hematophagous species, there are not too many who are after you. “Very few of them are interested in feeding on human blood,” Siddall says. “Certainly they’ll do it, if they’re given the opportunity, but they’re not what they’re spending most of their time feeding on.” 

2. Leeches are everywhere.

Japanese leech on a log
Pieria, Wikimedia Commons // Public Domain

“Every continent on the planet has leeches, with the exception of Antarctica,” Siddall says. “And even then there are marine leeches in Antarctic waters.” Humans have co-existed with leeches for so long, according to Siddall, that just about every language has a word for leech. 

3. Leeches have made a comeback in medicine.

Bloodletting for bloodletting’s sake has fallen out of favor with Western physicians, but that doesn’t mean medicinal leeches are enjoying a cushy retirement. Today, surgeons keep them on hand in the operating room and use them as mini-vacuums to clean up blood. “That is a perfectly sensible use of leeches,” Siddall says. Other uses, though, are less sensible: “The more naturopathic application of leeches in order to get rid of bad blood or to cure, I don’t know, whatever happens to ail you, is complete hooey,” he says. How on Earth would leeches take away bad blood and leave good blood? It’s silly.” 

4. Novelist Amy Tan has her own species of leeches.

Land-based leeches made an appearance in Tan’s 2005 book Saving Fish from Drowning, a fact that instantly put the author in leech researchers’ good graces. “There are not a lot of novels out there with terrestrial leeches in them,” Siddall says. So when he and his colleagues identified a new species of tiny terrestrial leeches, they gave the leech Tan’s name. The author loved it. “I am thrilled to be immortalized as Chtonobdella tanae,” Tan said in a press statement. “I am now planning my trip to Queensland, Australia, where I hope to take leisurely walks through the jungle, accompanied by a dozen or so of my namesake feeding on my ankles.”

5. Leeches can get pretty big.

The giant Amazon leech (Haementeria ghilianii) can grow up to 18 inches and live up to 20 years. And yes, this one’s a blood-feeder. Like all hematophagous species, H. ghilianii sticks its proboscis (which can be up to 6 inches long) into a host, drinks its fill, and falls off. Scientists thought the species was extinct until a zoologist found two specimens in the 1970s, one of whom he named Grandma Moses. We are not making this up.

6. Leeches make good bait.

Many walleye anglers swear by leeches. “A leech on any presentation moves more than other types of live bait," pro fisher Jerry Hein told Fishing League Worldwide. "I grew up fishing them, and I think they're the most effective live bait around no matter where you go." There’s an entire leech industry to provide fishers with their bait. One year, weather conditions kept the leeches from showing up in their typical habitats, which prevented their collection and sale. Speaking to CBS news, one tackle shop owner called the absence of leeches “the worst nightmare in the bait industry.”

7. Leech scientists use themselves as bait.

Siddall and his colleagues collect and study wild leeches. That means hours of trekking through leech territory, looking for specimens. “Whether we’re wandering in water or traipsing through a bamboo forest,” Siddall says, “we are relying on the fact that leeches are attracted to us.” Do the leeches feed on them? “Oh my god, yes. We try to get them before they feed on us … but sometimes, obviously, you can’t help it.”

8. Leech sex is mesmerizing.

Like many worms, leeches are all hermaphroditic. The specifics of mating vary by species, but most twine themselves together and trade sperm packets. (The two leeches in the video above are both named Norbert.)

9. Some leech species make surprisingly caring parents. 

“There’s a whole family of leeches that, when they lay their eggs, will cover them with their own bodies,” Siddall says. “They’ll lay the eggs, cover them with their bodies, and fan the eggs to prevent fungus or bacteria from getting on them, and then when the eggs hatch, they will attach to the parent. They’re not feeding on the parent, just hanging on, and then when the parent leech goes to its next blood meal it’s carrying its offspring to its next blood meal. That’s pretty profound parental care, especially for invertebrates.”

10. You might be the next to discover a new leech species. 

Despite living side-by-side with leeches for thousands of years, we’ve still got a lot to learn about them. Scientists are aware of about 700 different species, but they know there are many more out there. “I’ll tell you what I wish for,” Siddall says. “If you ever get fed on by a leech, rather than tearing off and burning it and throwing it in the trash, maybe observe it and see if you can see any color patterns. Understand that there’s a real possibility that it could be a new species. So watch them, let them finish. They’re not gonna take much blood. And who knows? It could be scientifically useful.”

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