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The big news is out. Today the eagerly awaited press conference at the American Geophysical Society meeting in San Francisco on the recent results from the Mars rover Curiosity was finally held. The announced results had been hyped like crazy when rumors began to spread a few weeks ago that Curiosity had discovered something truly spectacular.
Well, here are some of the headlines heralding the results.
- Nature: Mars rover finds carbon in its first soil sample analysis
- Washington Post: Mars rover Curiosity finds organic compounds, not life
- LA Times: Curiosity finds signs of chlorine in Mars’ soil; carbon iffy
- Sky & Telescope: Curiosity gets a whiff of organic matter
- Popular Mechanics: Curiosity finds simple organics, but big questions remain
- National Geographic: Mars rover detects simple organic compounds
Everyone one of these headlines touts the discovery of simple organic compounds as the big news. The trouble is, these organic compounds are not life, but merely simple molecules that include carbon in their molecular structure. Moreover, the scientists were not tremendously surprised by their detection. Their presence could simply be contamination on the rover from Earth, or a simple by-product of the chemistry of the Martian surface. To quote Kelly Beatty’s well written article for Sky & Telescope, despite the deceptive headline:
The instrument did identify some simple organic molecules, variations of methane (CH4) in which chlorine atoms have substituted for one or more hydrogen atoms. But there’s a huge caveat: it’s very unlikely that chlorinated methane actually exists on Mars. Instead, SAM’s tiny ovens probably caused perchlorate molecules (found commonly in martian dirt) to release lots of chlorine and oxygen as they broke down.
Perchlorate was found by the Phoenix lander, and was also theorized as the cause behind the chemical reactions detected by the Viking landers in 1976. Thus, even if the organic compounds are from Mars, they are likely nothing more than a by-product of ordinary Martian surface chemistry.
What is clear from all of these headlines is an effort by these news organizations to hype up the Curiosity results today in a way that really has nothing to do with today’s science results. Or to put it another way, it is an example of poor journalism. Rather than find out what the real story was, these journalists focused on an imaginary discovery that really didn’t happen: The possibility that Curiosity found evidence of life on Mars.
There were two significant facts however from today’s results, neither of which has anything to do with the discovery of life. One of these discoveries was also not covered by any of these articles, and would probably never be covered by most media outlets, merely because it is a discovery of basic science and not flashy.
First, the chemical data has confirmed that Martian water is five times more enriched with deuterium than water on Earth. Deuterium is a hydrogen isotope that is heavier because it carries a single neutron in its nucleus, unlike ordinary hydrogen which does not. This important discovery, the focus of this Cosmos Magazine article as well as mentioned in only one the above articles, from Sky & Telescope, is significant in that it confirms what scientists have long believed but hadn’t really proven until now, that Mars once had a much thicker atmosphere with far more water and hydrogen. Because of the planet’s weak gravity, however, that atmosphere has slowly leaked away, with the lighter hydrogen atoms flying into space and the heavier deuterium atoms remaining trapped on the planet. This new data confirms this fact, which also tells us a great deal about the evolution of this planet’s environment over time.
Second, there is this graphic, comparing the chemical analysis from Curiosity with that of the Spirit and Opportunity rovers.
What is remarkable about this data is how similar the results are from all three rovers. For the Martian surface at least, this data proves that the planet has some very basic components that are similar in widely different places. It is also gives scientists a solid baseline for further research. The goal now is to find significant deviations from this baseline, which Curiosity will hopefully do once it begins to climb Mount Sharp. Once it finds these deviations, scientists will finally be able to begin to map out the true geological make-up of the planet Mars.
And that will be the real news, because then we will finally begin to learn something fundamental and basic about the angry red planet.