Organic Materials on Mars

Mars soil samples, courtesy NASA

Space.com reports that NASA's Curiosity Mars rover has detected organic materials on Mars' surface, that is, compounds containing carbon. What's interesting is the assumptions by which they interpret the discovery:

However, the science team can't yet be sure whether these compounds truly come from Mars, or arise from contamination transported to the Red Planet onboard Curiosity.

Notice the only two sources currently being considered for the organic material:

1. It grew on Mars, and is evidence of life evolving independently on Mars
2. It was contamination brought by the Curiosity rover from Earth

 We see this clearly in the following:

"Even though [Mahaffy's] instrument detected organic compounds, first of all we have to determine whether they're indigenous to Mars," said John Grotzinger, Curiosity's project scientist.

Indigenous or contamination... But what about a third alternative? That the organic material came from Earth some time in the ancient past, say around 4,000 years ago? That would imply a catastrophic event, one that in the minds of many scientists is unthinkable. Read Chapter 7 of Beyond Earth and find out why.