Even if life doesn’t exist there now, it could someday. Part of making Mars a more hospitable place to live might require some monumental efforts to change the atmosphere there by a process known as terraforming: deliberately modifying features of the planet to be more like Earth. We could take a lesson from our own global warming problems and start releasing CO2 into the atmosphere of Mars. Melting Martian polar caps would be a good start. That would liberate CO2 and possibly methane, both greenhouse gases locked up in the permafrost. The liberated CO2 would thicken the atmosphere and, like pulling on a blanket, would warm the place up nicely.
Zubrin has several ways to get this blanket growing. One is to establish factories on Mars to produce artificial greenhouse gases. Raising the temperature of the Martian south pole by 7 degrees Fahrenheit (4 degrees Celsius) this way could initiate a runaway greenhouse effect, which could trap even more heat. One promising and long-lasting greenhouse gas fit for the job would be halocarbons such as chlorofluorocarbons (CFCs), the kind formerly used as coolants in refrigerators and as propellants in some aerosol cans. However, we would have to choose our halocarbons carefully, picking only those without chlorine.
“Using CF gases [as opposed to CFCs] will allow the ozone to persist, while the CF gas adds to the greenhouse effect,” says Zubrin. Fluorocarbons, such as CF4 (Tetrafluoromethane), could be used instead of CFC gases to create a greenhouse effect without destroying the ozone layer.
Martian explorers might use large orbital mirrors to concentrate sunlight on the poles. A space-based mirror with a radius of 77 miles (125 kilometers) reflecting light back on the Martian south pole could do the trick. An aluminized mirror about four microns (four-thousandths of a millimeter) would weigh about 220,000 US tons (200,000 metric tons), which would be impossible to haul from Earth. But the space-based manufacture of the mirror could be accomplished on a Martian moon or an asteroid.
There is a political aspect to this as well. If America wants to pick up the race to Mars again, the nation would have to time it right. The US window of opportunity, according to Zubrin, is eight years. That’s the maximum length of an American presidential administration. In 1961, President Kennedy set a goal of reaching the moon by 1970. By 1968, administrations had changed, and even as the Apollo astronauts were landing on the moon, President Nixon was putting the brakes on future projects.
With the shuttle flights terminated, the US human space flight program appears to be in limbo, and space travel may have to be an international effort. In 2012, a Russian-Chinese effort called Fobos-Grunt (“Phobos-Ground”) was set for an ambitious sample return mission to Mars’s largest natural satellite, Phobos. However, Fobos-Grunt failed to perform an orbit-raising maneuver two and a half hours into its flight, and it never left Earth’s orbit. The aim of taking soil samples on planetary moons remains a respectable one, but it may be one for the future. Remember, there were multiple failures in both the US and Soviet space programs before there were successes.
Carl Sagan, a popular American astronomer, cosmologist, and prolific author, was a strong advocate for a combined American-Soviet effort. He saw it as a way of bringing together former rivals and building trust, but both sides were reluctant to share missile technology, which could be used to send warheads. The shuttle-Mir program provided a taste of the benefits of cooperation. Between 1994 and 1998, space shuttles made a total of eleven flights to Mir, the Russian space station. American and Russian scientists also conducted experiments to determine how animals, plants, and humans would endure in space. With the demise of the US shuttle program, cooperation has diminished.
Zubrin thinks that the best choice is for the US, perhaps in conjunction with Russia, the European Union, and China, to offer a prize of, say, $20 billion for the first private organization to land a crew on Mars and to return them to Earth. This path could bring down the costs of space travel substantially. Zubrin believes that space travel under bureaucratic control is a recipe for high prices, and he thinks the private sector is often vastly more efficient because it does not require consensus to try something new. You need only one innovator and one investor.
According to Zubrin, the real cost of such a mission, pared down and under private control, would be closer to $4 to $6 billion. In this scenario a $20 billion prize would be a nice incentive. Offering a range of prizes could get things going: Let’s say $500 million for a successful Mars orbiter imaging mission. Perhaps $1 billion for the first system that uses propellants of Martian origin to lift a 4.5-US-ton (4-metric-ton) payload from the surface of Mars to its orbit. And a $20 billion grand prize to someone or some organization to send at least three crew members to the Martian surface, remain there for one hundred days, take three overland trips of at least thirty-one miles (fifty kilometers), and return the crew safely to Earth.
J. Craig Venter, through his companies Synthetic Genomics and J. Craig Venter Institute, based in Maryland and California, is trying to develop a DNA sequencing machine that could be landed on the surface of Mars, look for life in the soil, sequence it, and beam it back to Earth—the benefit being that the task could be accomplished without having to return the machine to Earth. Jonathan Rothberg, founder of Ion Torrent, in Connecticut, a DNA-sequencing company, is working on a similar effort.
Mars One, a Dutch nonprofit foundation, wants to set up a permanent space colony on Mars. The company thinks that the sale of broadcasting rights of a Mars reality show would be enough to finance an actual mission sometime in 2023. The company would start with televised episodes covering the selection of astronauts, trip preparations, and the flight to Mars. After landing, the company would then start streaming operations continuously from the surface of the Red Planet.
The Mars One plan is to launch 2.75 US tons (2.5 metric tons) of supplies in 2016, a Rover in 2018, and about six landers with living pods, supplies, and support systems in 2020. The first four astronauts wouldn’t arrive until 2023. A second human group would join them in 2025. The catch, however, is that the trip would essentially be one-way: there are no planned return flights. You would live your life out on Mars, and your remains would be cremated. The company says that the Martian community would decide what to do with your ashes.
Still, the company says they’ve had more than 100,000 applications from would-be astronauts eager to make the trip. Mars One will offer “to everyone who dreams the way the ancient explorers dreamed” the opportunity to apply for a position in a Mars One mission.
Lots to offer here, just no welcome-home party.
The greeting was more forthcoming when I pulled up to Biosphere 2 in the high desert near Tucson, Arizona. Pristine desert grasslands speckled with mesquite trees as well as prickly pear, cholla, and saguaro cacti surround the facility at the foot of the Santa Catalina Mountains. John Adams, the assistant director of the facility, took me inside to a real-time mini world with a tropical forest, a million-gallon ocean, a small savanna grassland, a fog desert, and mangrove wetlands. Biosphere 2 is a large futuristic structure of glass atriums covering an area equivalent to 2.5 football fields. The facility was one of the first to experiment with what life might be like on another planet, though its purposes today are a bit different.
“Biosphere 2 offers a way to study the effects of climate change on these different ecosystems but in a controlled environment. Scientists here are essentially performing carefully monitored laboratory-type experiments, but on a much grander scale,” says Adams.
Biosphere 2 began its own evolution as a different experiment. Its original purpose was to test the ability of man to survive in a closed, self-contained system—one completely shut off from the outside world, such as the one the explorers might encounter on Mars. The “Landscape Evolution Area” of the modern facility, now used to study soil formation, was formerly the “Agricultural System.” Space Biospheres Ventures, the original developers of Biosphere 2, had hoped that food grown in it would satisfy the nutritional needs of the first eight pioneers who entered the facility
in 1991.
That team was dependent on the facility’s different biomes and infrastructure for the food they ate and the air they breathed—which turned out to be the things that gave project directors the most trouble. The experiment lasted two years. The first year was rough for the gourmets in the group. The crew lost an average of 16 percent of their pre-entry body weights. However, Roy Walford, a professor of medicine at the University of California, Los Angeles, and the medical doctor for the first Biosphere 2 experiment, was then promoting a low-calorie, nutrient-dense diet as a way to increase longevity. So even though the team claimed “continual hunger” in their first year of isolation, Walford happily reported that the group’s cholesterol and blood pressure both went down.
But the researchers here suffered from more than loose pants; they also needed to adjust to the levels of CO2, which fluctuated wildly. Most of the pollinating insects died, though insect pests like cockroaches boomed. Morning glories overgrew the rain forest, blocking out other plants. The worst was that oxygen inside the facility, which began at 20 percent, fell gradually over sixteen months to 14.5 percent. The project began pumping oxygen into the system to make up for the failure, but the press caught them and cried foul.
Space Biospheres Ventures officially dissolved on June 1, 1994, after a second mission failed and federal marshals served a restraining order on the on-site management team regarding questions of authority. If Biosphere 2 had been on Mars, the occupants might have starved to death or succumbed to slow asphyxiation.
Biosphere 2 is an example of how long-term occupancy of a space station on a planet that is millions of miles from Earth could be extremely dangerous and fraught with perils that science may not yet know enough about.
On the positive side, if we can overcome these hazards, then a Mars station might offer a place where Homo sapiens can truly differentiate—becoming a new species. Carol Stoker, a planetary scientist at NASA’s Ames Research Center, envisions a permanent research base of closed environments on Mars as the next most logical place to live outside of Earth. Still, she claims a child who grew up on the Red Planet, with one-third the gravity of Earth, would never have the physical or skeletal structure to survive on our Blue Planet.
“It is likely that a second-generation Martian would be physically unfit to walk unaided on Earth, at least without intense weight and strength training,” says Stoker. “Just imagine if you suddenly weighed three times what you weigh now. Could you walk? Would your deconditioned heart be able to pump the blood volume needed? Whether we know it or not, we are constantly doing a lot of work against gravity.”
The European Space Agency, the National Space Biomedical Research Institute (in Houston, Texas), and the Russian Federal Space Agency recently completed a 520-day experiment locking six “marsonauts” in a simulated spaceship near Moscow. Five hundred and twenty days is about what it would take for a round-trip flight to Mars, with about thirty days to explore the surface. During the entire simulation, the crew went without sunlight, fresh air, or fresh food.
There were significant human problems to work through. With regard to rest, there were no external cues, such as sundown, to let the astronauts know when it was time to sleep. They had to rely on artificial cues like watches and other astronauts waking them up. Without gravity, the body had trouble telling what was up and what was down. In space, the natural orientation of the body is taken away, particularly for arms and legs. On Earth, vision, hearing, and touch combine to tell you where you are. You feel the floor under your feet, the chair that you sit upon. But weightlessness takes away those feelings, and the senses send confusing signals to the brain, which results in motion sickness.
The big thing, however, was the effect to bodily organs, particularly the cardiovascular system. While in space, the body no longer feels the downward pull of gravity that distributes the blood and body fluids to the lower extremities. Fluids start to accumulate in the upper body, away from the legs and feet. In space, astronauts actually start to look different as their faces puff out from the additional fluid in their upper bodies. They develop bird legs as the circumference of their legs shrinks due to decreased fluid in the lower body.
The heart has less work to do because it takes less energy to float around a spacecraft than it would to walk or run around planet Earth. Bones lose calcium, making them weaker, and the muscles atrophy because gravity is not providing the normal resistance to movement. Exercise machines aboard the flight can mitigate some of these effects, but that doesn’t eliminate all the aftereffects. Most Russian cosmonauts, after spending months in space, were carried away from the spacecraft on special stretchers. At their homecoming receptions, climbing the podium was often too challenging so soon after reentering Earth’s gravity.
Interplanetary travel would be a major evolutionary force for Earth-born settlers on Mars, and frequent travel between Earth and Mars would be unlikely because of the expense. Living on Mars could produce long-term biological changes that would make a return to Earth ultimately impossible. With isolation a natural part of the job, the gradual push of evolution toward becoming another species could happen in outer space just as well as here on Earth.
Gravity wouldn’t be the only selective force. Others would include breathing compressed air and adjusting to different loads of UV radiation. The need to eat, go to the bathroom, have sex, give birth—all these vital functions would be seriously altered by changes in gravity, air, and radiation.
But even though such a change would be an interesting step in the evolution of man, it doesn’t answer the primary question of life on Mars. Is it someplace where large portions of our population might escape if we mess things up down here?
There are so many things that could go wrong, one of which is that the reality TV show on Mars gets canceled due to lack of an audience and the venture runs out of cash. And there are other “little” things, like what happened with Biosphere 2’s oxygen, which wasn’t expected. Biosphere 2’s soil was rich in organic material that was taken up by microbes, which used up oxygen and created a lot of CO2. The plants in the facility should have been able to process the CO2 and produce more oxygen, but it was later determined that calcium hydroxide in the concrete was removing the CO2 and not releasing oxygen. No one would have imagined that the concrete in Biosphere 2 might eventually suffocate the residents.
After Mars, the next likely place for life in our solar system is the moons of Jupiter. That planet has four large moons and at least forty-six smaller ones. Io, for example, is the most volcanically active body orbiting Jupiter. Io’s surface is covered by sulfur in different colorful forms, and its volcanoes are driven by hot silicate magma. One could keep warm next to an Io volcano, but it would be hard to get insurance. Europa’s surface is mostly water ice. It may be covering an ocean of water or slushy ice beneath. This would create a “habitable zone” for microbes but it wouldn’t be a place where you would want to spend your vacation, let alone the rest of your life.
Scientists are currently looking for habitable planets like Earth around other stars in our solar system, and they’ve found numerous prospects. But the closest star in our solar system, Alpha Centauri B, is about 4.37 light-years away from our sun. One light-year is about 6 trillion miles (10 trillion kilometers), which means Alpha Centauri B is about 26 trillion miles (41.5 trillion kilometers) from our sun. NASA’s Kepler planet-finding spacecraft has found Earth-like planets around distant stars, only they’re 275 times more distant.
Interstellar travel could happen one day in the distant future, but it’s just as likely that mankind will have exhausted Earth’s natural resources and made the planet unlivable before then. Right now mankind seems uninterested in either goal. What’s the chance that evolution could provide the world with another species that could outcompete us and change the course of human history?
14
IS HUMAN EVOLUTION DEAD?
MANY SCIENTISTS hold the belief that natural evolution stopped for Homo sapiens
about forty thousand to fifty thousand years ago in Europe. That’s when man began to chart his own destiny apart from nature. Human inventions like sewing needles provided warm clothes to protect against the cold as opposed to natural selection providing more hair. Man began to think in symbols, which morphed into words, and this expanded into complex language. And language provided the key to elaborate cooperation.
This wasn’t just hoots and loud calls with others in a group for the purpose of bringing down an animal. Language was useful for establishing trade that could reach across vast distances, relaying experiences across large chunks of time, and learning where the best food was and how to get it.
Man began to utilize an ever more complex set of tools: spears, spear throwers, bows and arrows. He grew leaner. He didn’t need large muscles and thick bones to kill game at close range—he killed from a distance. The new weapons rewarded those with a better throwing arm and a better aim. The atlatl (spear thrower) and the bow allowed modern humans to kill large animals without having to have large muscles. Thus, humans could run faster, cover more ground, and not have to eat as much.
With the invention of nets, harpoons, and hooks, humans began to fish. It was less dangerous and required less physical effort. One could now eat meat, fish, and berries—a broad-based diet that gave man the advantage in a world that was then in the middle of an ice age. The use of fire and pottery for cooking made large teeth less vital and man’s jaw and teeth began to recede. Cultural innovation began to affect evolution.
Yet Stephen Jay Gould, the late Harvard paleontologist, looked at all this and hesitated to give it an evolutionary consequence. Gould thought that fifty thousand to one hundred thousand years was but the blink of an eye in evolutionary development and far too rapid to see any significant evolutionary changes. But Gregory Cochran and Henry Harpending, anthropologists at the University of Utah, in Salt Lake City, say there has actually been an increase in genetic change in modern man in the last ten thousand years. In their book The 10,000 Year Explosion: How Civilization Accelerated Human Evolution, they propose that not only has human evolution not stopped, it has accelerated. Their belief is that evolution is now happening about one hundred times faster than the long-term average of our species’ existence. Could that lead to a new species?
The Next Species: The Future of Evolution in the Aftermath of Man Page 24
