The scientific, cultural, and political implications of the possible discovery of past life on Mars were discussed at a symposium at George Washington University in Washington, DC, November 22.
A full house of several hundred people, mostly members of the general public, attended the day-long event to learn more about how the August announcement of evidence of life in a Martian meteorite might effect our understanding and perception of Mars, and what it might do to future plans to explore the Red Planet.
The symposium was organized by George Washington University's Space Policy Institute and was sponsored by the National Space Society and the Planetary Society.
The Science Behind the Discovery
Kathy Thomas-Keprta, one of the members of the team that found evidence of past life in meteorite ALH 84001, gave a presentation outlining the evidence for life found in the meteorite. Nicknaming the meteorite as the "Green Bay Packer meteorite" for the greenish pyroxene body and golden carbonate inclusions, she pointed out cracks in the rock where water flowed in billions of years ago, creating the carbonate inclusions. The inclusions, she claimed, were deposited with the aid of bacteria.
Samples of the rock had organic molecules known as polycyclic aromatic hydrocarbons (PAHs) embedded in them. Although PAHs are found in other meteorites, the samples found here are not similar to other meteorites but more similar to the products produced during the decay or biological organisms. The distribution of PAHs, with little near the surface and more in deeper layers, indicate that the PAHs came from Mars and are not terrestrial contamination.
Viewing the inclusions with a transmission electron microscope that magnified samples by up to a factor of a million, the team could find samples of minerals like magnetite and greigite. The size and shape of the crystals, as well as their distribution in layers in the carbonates, suggest that they were created by bacteria, just as such minerals are created by terrestrial bacteria.
Using a scanning electron microscope on the surface of the inclusions found the tubular, ovoid structures identified as possible microfossils. However, at only 1 micron (1 millionth of a meter, or about 40 millionths of an inch) long, they are up to 100 times smaller than similar terrestrial microfossils, casting doubt on their claims.
However, Thomas-Keprta pointed out, nannobacteria found in samples of the Columbia Rover Basalt at a depth of 1 to 2 kilometers are superficially similar to the Martian microfossils, including being about the same size.
In addition to the summary of the work the team had previously done, Thomas-Keprta provided an update on current results and work. She and others will be examining the nannobacteria samples found in the Columbia Rover Basalt to look for cell walls and other features of organisms, then look for similar features in the Martian microfossils. A team at Stanford University will be using their mass spectrometer, which found the PAHs, to look for any amino acids in the meteorite. More work is also being done to study the concentration of various elements in the carbonate globules to compare them with terrestrial samples.
While the results of the work by Thomas-Keprta and others have come under criticism in some quarters, their work is "not at all similar to cold fusion," reassured John Grotzinger, a professor at MIT's department of earth, atmospheric, and planetary sciences.
Grotzinger pointed out there may be many parallels in the development of life on the early Earth and Mars, with evidence of primitive life nearly 4 billion years ago now seen on both planets
One sign of life found on the early Earth which may exist on Mars, Grotzinger said, is stromatolites, common sedimentary structures from the seafloor of the early Earth which may have been created by life. Such stromatolites would be easier to find than microfossils.
However, stromatolites can also be formed by inorganic processes, which makes finding a way to determine the origin of these features an important step before they can be used to identify past life.
Culture Shock, or Lack Thereof
One would expect that the discovery of past or possibly even present life on Mars would create quite a shakeup in our understanding of the universe and our place in it. However, such an event might have far less of a impact than one might expect, as our popular culture has conditioned us to expect extraterrestrial life and our religions are willing to accept it.
Kim Stanley Robinson, author of the trilogy "Red Mars", "Green Mars", and "Blue Mars", discussed the role of science fiction in our acceptance of extraterrestrial life. Robinson gave a history of Martians in science fiction, from H. G. Wells' "War of the Worlds" (an allegory of the British imperial movement) to the present, noting how Martians evolved -- usually downwards -- as we learned more about the Red Planet and found intelligent life there to be less and less likely.
This treatment of Martians in culture has made it far easier for people to accept the possibility of past life on the planet. He noted that the general reaction in the U. S. to the August announcement was, "Well, of course."
Still, he acknowledged that, "I don't know if I could have written the same book [about Mars] after the discovery."
Steven Dick, an astronomer and historian of science at the U. S. Naval Observatory, noted that the discovery of past life on Mars is just another step in the process that started with Copernicus moving the Earth out of the center of the universe. No longer are we, or our Sun, or our galaxy, in the center of the universe, and no longer is life something special for the Earth alone.
The discovery of past life on Mars may upset religious foundations far less than what some might expect. The Rev. John Minogue, president of DePaul University, phrased the discovery in the light of several questions, such as ethics versus religion, a unique savior versus a cosmic force, and a shrinking God versus a growing universe.
In a presentation that referenced in equal parts the Bible and Gary Larson's "The Far Side" cartoon, Minogue admitted that religion was much less flexible than science when dealing with data that requires a new interpretation, but said that it was "fundamental to the human race that we are pursuing unanswered questions" like life on Mars.
Abdul-Monem Al-Mashat, the counselor director of the Egyptian Cultural and Educational Bureau in Washington, provided an Islamic perspective on the discovery. Al-Mashat noted that there are references to a "heaven inhabited by wise, human-like beings" in 35 places in the Koran, which he interpreted to mean extraterrestrial life.
Al-Mashat said the August discovery "shouldn't be a surprise to Muslims" and more discoveries should be expected.
The Political Battlefield
How does the announcement of past life on Mars, and the cultural acceptance of the discovery, translate into political will for more Mars missions, unmanned and manned? Several speakers gave differing thoughts on the hopes for future Mars exploration.
Bruce Murray, former director of JPL and current vice president of the Planetary Society, said that we "can't do everything people are proposing" and a "downsizing" of ideas needs to take place, developed around a shared long-term goal and a vision that can be articulated.
Murray pointed to three "tough issues" that need to be addressed in the formation of any long-term Mars policy. One was whether to focus on "open-ended adaptive exploration" leading to manned missions, or to focus on well-defined scientific objectives. The second was whether to look for evidence of life on Mars or try to understand the overall history of the planet. The final issue was whether to invest in long-term exploration versus an expedient approach with near-term objectives.
Murray suggested his own plan, which included an early sample return mission; a search from orbit for "oases" of high heat flow which might have harbored life, or may do so today; the development of long-range roving and rock analysis capabilities; and work on technologies for future robotic or human expeditions.
Murray said that with NASA's declining budget and the high priority given to the International Space Station, it may be difficult to fund future work. Cuts in other space science programs may be the only way to fund additional Mars research.
Roald Sagdeev, formerly with the Institute of Cosmic Research in the former Soviet Union, provided an international perspective on missions to Mars, with an emphasis on the failed Mars 96 mission.
Sagdeev said the current debate on the cause of the Mars 96 mission is between NPO Energia, the company that made the booster stage that was to send the spacecraft to Mars, and the company that made the "control block", the guidance system within the spacecraft. Sagdeev indirectly provided his opinion on the debate by noting that the Block D stage had worked fine in 17 previous launched dating back to 1973 and that the control block used in Mars 96 was made by the same company that made the control block for Phobos 2, which was also implicated in the loss of that spacecraft.
Sagdeev said the Mars 96 failure and other problems mean that it will "take a long time for the credibility of the [Russian] space community to be restored."
He urged the United States to take the lead in international cooperation on Mars missions, saying other countries were "begging" the U. S. to take the leadership role. However, he warned that it is a "very dangerous misconception" that the U. S. is the only country working on space science.
Robert Zubrin gave his presentation on his Mars Direct proposal for manned Mars missions. He said there should be do debate between robotic and human missions to Mars, but that there are many things humans can do on Mars which robots cannot. As one example, he noted that the robotic spacecraft planned for Mars would, if sent to explore the Earth instead, be unable to find evidence of dinosaur fossils, let alone microfossils.
Zubrin said a manned mission to Mars doesn't have to be expensive, and people only think it's expensive because of the 1989 NASA study which put a $450 billion price tag on a mission. "They don't have to fly to Mars in the Battlestar Galactica," Zubrin pointed out.
Zubrin finds the key problem to be a lack of focus, not money. He noted that the average budget for NASA between 1961 and 173, adjusted for inflation was $15.4 billion, or less than 20% more than the current budget.
An important part of any Mars program ,according to Zubrin, would be educational spinoffs. With 50 million Americans in pre-college studies now and an additional 50 million through 2008, an additional one million new scientists and engineers could be created if just one percent of the students are inspired by the mission.
NASA Administrator Dan Goldin rounded out the symposium with a talk where he suggested a manned mission to Mars might be ready as soon as 2012, provided several needed things are obtained and several challenges overcome.
Goldin said that NASA and the American people needed three things for a Mars program to succeed. One was a broad vision of a permanent presence on a planet other than the Earth, and as part of NASA's Origins Program to understand how the universe and life started. The second was the need to identify the challenges that must be overcome for any plan to succeed. The third was the need to recognize the cornucopia of benefits that would result from such a program.
Two of the challenges that must be overcome, according to Goldin, are cost and time delays. At the current cost of $10,000 per pound of payload to low earth orbit, a single Mars expedition might cost $12 billion dollars, and six such missions over a ten-year period would account for more than half of NASA's budget. Goldin said NASA is working to get launch prices down to $1,000 a pound, and then eventually to $200 a pound.
The second challenge, time delays, stems from the delays of up to 40 minutes for round-trip communications between the Earth and Mars. Such a delay could be dangerous or fatal to a crew, requiring the development of expert systems to aid future crews.
"Doing it the way we know how to do it is not how we want to do it," Goldin summarized.
If those problems can be overcome, Goldin suggested an international program for a manned Mars mission could begin as early as 2004, after the International Space Station is completed. Under such a program, a manned mission could take place as early as 2012.
"We are going to do it," Goldin said. "NASA is going to impact the future."
Students of George Washington University's Space Policy Institute released initial results on a survey seeking understand the public's opinions on Mars life and the future of Mars exploration. Of the 233 respondents via the Internet, over 60 percent thought the discovery of past life on Mars was one of the biggest discoveries ever. Other interesting statistics: 46% thought it was very important the United States took the lead in Mars exploration, 56% thought a manned mission should start as soon as it's technically and financially possible, and 83% thought there should be some kind of increase in NASA's budget. Full survey results will be released by GWU in the near future... Best quote from the conference: "PAHs [polycyclic aromatic hydrocarbons] make poor conversational companions." -- Peter Caws, professor of philosophy, GWU... If one wanted any further proof that the discovery of past life on Mars had a smaller impact than some might have thought, one only needed to hear Richard Berendzen. The physics professor from American University commented that he and Goldin had been invited to appear on Nightline that night to talk about Mars, only to have the offer apologetically withdrawn. The reason? Nightline wanted to cover something of apparently far greater significance: the testimony by O. J. Simpson that day in his civil trial.