The Viking Mars Missions May Have Discovered Life in 1976

Num7

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Since the Viking Mars probes traveled to the red planet back in 1976, NASA has sent several more probes, landers, and rovers to the Martian surface to study the planet’s geology and search for signs of microbial life. But the evidence for life may have been hidden in Viking’s data all along. A new analysis of the data collected by probes Viking 1 and Viking 2 suggest the missions found evidence of microbial life more than three decades ago.

The new analysis centers on one of the three experiments carried by the probe: the Labeled Release (LR) experiment. This instrument searched for signs of life by mixing samples of Martian soil with droplets of water containing nutrients and radioactive carbon. If the soil contained microbes, the reasoning went, they would metabolize these carbon atoms and nutrients and release either methane gas or radioactive carbon dioxide, either of which would tip off the probes that life existed in the soil.

That’s exactly what happened. But other experiments aboard Viking didn’t back up the LR, and NASA scientists had to dismiss the LR’s findings as anomalous.

But now an analysis by a University of Southern California neurobiologist (and former NASA space shuttle project director) and a mathematician from Italy’s University of Siena could reverse that thinking. They used a technique called cluster analysis, which clusters together similar-looking data sets, to see what would happen. They found the analysis created two clusters: one for the two active experiments on Viking and the other for five control experiments.

Further, when they compared Viking’s data to confirmed biological sources on Earth, like temperature readings from a lab rat, the analysis correctly clustered the biological readings with the active Viking experiment data, separate from the non-biological data in the control experiments. All that essentially means that the cluster analysis, when fed a good deal of data from both biological and non-biological sources, correctly separates the two types of data. And when it does so, it lumps the Viking data into the “biological” category.

That’s not concrete evidence for microbial life on Mars. It’s merely concrete evidence that there is a stark difference between Viking’s LR experiment data and the control experiment data. And it’s evidence that the Viking data tracks with biological rather than non-biological data. More study is necessary (isn’t it always?), but if the cluster analysis is to be believed then our first shot at detecting microbial life in the soils of Mars may have hit pay dirt--and we didn’t even realize it.

Read complete article:
The Viking Mars Missions May Have Discovered Life in 1976 | Popular Science
 

Peregrini

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This is very interesting info Numenorean7 but, two paragraphs bother me a little bit.
I didn't recall Cluster Analysis from college. I did tons of statistical work and if this was covered it must have been only in passing or perhaps I had a hangover that day so I looked it up and I did recognize parts of it. I got this from wiki;
Cluster analysis as such is not an automatic task, but an iterative process of knowledge discovery or interactive multi-objective optimization that involves trial and failure. It will often be necessary to modify preprocessing and parameters until the result achieves the desired properties.
Cluster analysis - Wikipedia, the free encyclopedia
I've highlighted the pertinent parts.

That statement bothers me in that it alludes to biasing your data toward a desired result. IMHO a big NO NO in statistical analysis. The phrase often attributed to Samuel Clemens aka Mark Twain...There are three types of lies. There's lies, damned lies, and statistics. The above lends credence to that statement.

The second from the article itself;
Further, when they compared Viking’s data to confirmed biological sources on Earth, like temperature readings from a lab rat, the analysis correctly clustered the biological readings with the active Viking experiment data, separate from the non-biological data in the control experiments. All that essentially means that the cluster analysis, when fed a good deal of data from both biological and non-biological sources, correctly separates the two types of data. And when it does so, it lumps the Viking data into the “biological” category.
The Viking Mars Missions May Have Discovered Life in 1976 | Popular Science

The word "correctly" again indicates a bias toward a specific outcome. That is not the case in true statistical analysis. I'm not saying there is no bias in statistical analysis but that it should be minimalized. Only the result should be debated. The data should not be adjusted for a desired result. Again IMHO.

But, as far as life on Mars, why not? I believe life can exist in many less than optimal conditions. The term "life as we know it" should be scraped from the language. The extreemophiles already discovered lend proof to my belief. There could very well be some form of life living underground. Human, human like, or our ancestors? Maybe someday we will know for sure. There are several other places that life is now believed to possibly exist.
Jupiter's Moon, Io --Could Extreme Life Thrive There?
Ice cavern 'could support life' on Jupiter's moon Europa - Telegraph
 


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