I have a fuzzy recollection of going to the Smithsonian Air & Space Museum when I was a kid in the late 1980s. There was an exhibit about whether or not Mars hosted life. On display was a clear plastic tube, filled halfway with dirt. There was a shallow layer of water and the surface was bubbling. To my kid brain, this was dirt from Mars and the fact that the water was bubbling clearly indicated life – not some pump hidden behind the display. I wasn’t really into space or science fiction or aliens, but this stuck with me. I was very willing to be deceived if it meant that life existed on Mars.
As it turns out, I was in good company. The other day, the opening lines of a New York Times article titled “Life On Mars? Maybe Not” caught my eye:
In findings that are as scientifically significant as they are crushing to the popular imagination, NASA reported Thursday that its Mars rover, Curiosity, has deflated hopes that life could be thriving on Mars today.
If you are thinking, “Didn’t we already know this,” you are right…some of the time. The search for life on Mars has been a parabolic endeavor, with each robotic mission setting out to do just that and ultimately coming up discouragingly short of its ultimate goal. Before each Mars mission, there is a build up of excitement before the data comes back negative and a new life finding strategy must be devised. These ups and downs are well recorded in the coverage of the search for life on Mars in the popular press, as I’ll show below. Since 2009, I have circulated amongst planetary scientists as an anthropologist. Though none of my informants claim that Marvin the Martian is going to pop up in front of a rover, there is a simmering hope that a rover, after scraping back the top layer of soil, might find a Martian microbe. I suspect the new findings from Curiosity will do little to dissuade many of these scientists from their pursuit to find life on Mars.
In 1976, the Viking lander (the first successful robot to land on Mars) began beaming data back to eager NASA scientists. As reported in the first year of the mission, the tests were conflicting. Half pointed to evidence of life, the other half suggested just the opposite. A NASA sponsored conference in 1977 prompted The New York Times to report “Mars Probe Showed No Sure Sign of Life.” This same article outlined future missions, first rovers and then a sample return. Perhaps Viking failed because the landers were on poorly chosen, dead terrain. Mobile vehicles might be the key to life detection. This article announced a rover mission to be launched no earlier than 1986, perhaps followed by a sample return in 1990.
It wasn’t until 1997 that a rover successfully landed on Mars: NASA’s Mars Pathfinder and its roving companion Sojourner. Not designed as a life-finding mission, Pathfinder and Sojourner offered evidence that there was once water on Mars. And where there was water, there might have been life. This offered scientists trying to get over the disappointing Viking findings a way back into the question of life. In 2000, when NASA announced plans for what would be called Spirit and Opportunity, newspaper headlines described the missions as a search for life on Mars. Sure enough, the mid-2000s rewarded scientists with even more evidence from the rovers of a wetter and warmer Martian past.
Still, though, these missions lacked hard evidence of life, past or present. The London Times, reporting on the eve of the Phoenix mission – a NASA polar lander – stated that, “Many scientists and astronomers are happy to admit to believing that there is – or, at least, that there has been – life on Mars, even if the proof has yet to be found.” Phoenix failed to detect microbes and now, NASA’s latest life seeking rover, has reported a lack of methane, a gas produced by life as we know it. The New York Times article from last week, that I quote above, laments the scientific implications, but the article is also a funeral song for Mars and Martians as cultural icons.
Despite this new finding from Curiosity, there are many scientists still holding on to hope that Mars is or was once a living planet. What should we make of this willful neglect of the evidence coming from the past decades of robotic exploration? An op-ed written by Carl Sagan for The New York Times in 1976 suggests that we are eager to find life on Mars because the landscape seems so much like our own. Writing to keep the public from being discouraged by the lack of Martians, Sagan offers,
“The scene [from the Viking cameras] has a kind of haunting familiarity. Some of the rocks are shaped rather peculiarly and the sky is pink, even at noon; even so, the landscape has a recognizably terrestrial aspect. The possibility of life, even large forms of life, is by no means out of the question.”
Giving up on believing in life on Mars is letting go of a kinship that has long drawn our interest to the Red Planet. When I saw the tube of dirt – Earth dirt – at the Air and Space museum, I was drawn into a relationship with Mars born out of similarity. What does it mean to take this resonance away and mark Mars as ultimately, fundamentally different? I imagine the answer to this question will yet again be deferred as scientists once more reframe the search for life and hatch ideas for the “killer app” of Mars missions that will allow the Maritan microbe, at long last, to reveal itself.
 Kenneth Chang, “Life on Mars? Well, Maybe Not,” New York Times, September 19, 2013. http://www.nytimes.com/2013/09/20/science/space/mars-rover-comes-up-empty-in-search-for-methane.html?_r=0