Controversy Grows Over whether Mars Samples Endanger Earth

C A U T I O N A R Y C O S T S
Such statements reflect a growing sense of urgency among U.S. 
planetary scientists about making MSR a reality. In April NASA 
received the latest Decadal Survey on planetary science and 
astrobiology, an influential report produced by the National 
Academies of Sciences, Engineering, and Medicine that las out near-
future priorities for the field. One of the report’s main 
recommendations calls for the agency to shore up its plans for 
handling MSR’s samples, with an emphasis on readying a Mars 
Sample Receiving Facility in time to receive material from the Red 
Planet by 2031. 
To meet that deadline, NASA must start designing—and building—
such a facility immediately, says Philip Christensen, a professor at 
Arizona State University and co-chair of the new Decadal Survey’s 
steering committee. 
“Our recommendation was to not go off and build a very fancy, very 
complicated, very instrument-rich receiving facility,” Christensen 
says. “Instead make it as simple as possible. The number-one job is to 
verify that the samples are safe, then let them go to labs around the 
world that already have very sophisticated instrumentation.” 
John Rummel, a now retired astrobiologist who previously helmed 
NASA’s “planetary protection” efforts for its interplanetary missions, 
agrees that simplicity can save time but at uncertain costs. “Nobody 
wants to spend all the money in the world on a ‘Taj Mahal’ for 
[sample-return] science,” he says. Building a bare-bones facility could 
backfire, however, by failing to allow scientists to properly investigate 
whether any returned samples harbor evidence of life. 
More fundamentally, Rummel says, it simply isn’t true that we know 
enough about Mars to quantify MSR’s risks of interplanetary 
contagion. “In the first place, we don’t know everything we want to 
know about Mars. That’s why we want the samples,” Rummel says. 
“We keep finding Earth organisms doing new things that are quite 
interesting from the standpoint of potential life elsewhere. So why 
don’t we think we need to be careful? The answer is that we do need 
to be careful, as repeatedly emphasized by the National 
[Academies].... People have to have some kind of respect for the 
unknown. If you have that respect, then you can do a credible job, 
and the public is well-served by your caution.” 

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