The article below explains in a simple manner how circadian rhythms were detected in Viking data 25 years after these data were gathered. The evidence presented here is just one of many other evidence that there is life on Mars.
The article also reminds that Viking data have not been seriously treated.
By Leonard David
Senior Space Writer
19 may 2000
WASHINGTON - Where there's rhythm, can there be martian life? A scientist believes he sees tell-tale signs of microbes on Mars hiding in experiment results gathered nearly 25 years ago.
That prospect has kick-started a NASA restoration plan for data gleaned by two Viking Mars landers that touched down on the red planet in 1976. The planet snooping duo were specially equipped to search for martian biology.
This is all good news for Joseph Miller, a specialist in circadian rhythms. Working in the Dept. of Pharmacology at Texas Tech Univ. Health Sciences Center in Lubbock, Texas, he contends that data from a Viking biological experiment shows periodicity - a circadian rhythm that only life produces.
"This may be the strongest evidence for biology on Mars. It was completely missed by everybody," Miller told SPACE.com.
The rhythm of various metabolic activities of plants and animals is controlled by an intrinsic mechanism called a biological clock. Virtually all species of plants and animals on Earth run on a 24-hour, day-night cycle called circadian rhythm.
An expert in circadian biology, Miller has taken special interest in one of three Viking biology investigations conducted on Mars. Called the Labeled Release experiment, a sample of martian soil was mixed with a nutrient "soup" containing radioactive carbon-14.
If living organisms were in the soil sample, they would digest the radioactively-labeled nutrients, then give off gases indicating the presence of life metabolizing the nutrient. On Mars, the Viking assay detected a surge in the radioactivity of released gases.
"Every organism that we know of on Earth has a circadian rhythm. It's reasonable to think this holds true for any microbes on Mars."
Joseph Miller, specialist in circadian rhythms
Those results remain not only puzzling, but controversial as well.
The investigator behind the experiment, Gilbert Levin, President of Biospherics Inc., Beltsville, Md., has long held that the gas releases mean living microorganisms were found. Other experts counter that a nonbiological response was seen.
But in pouring over published results from that Viking experiment, Miller did a double-take. He saw evidence of martian life in a different way.
"There's a rhythm in the release of radioactive-labeled gas in that experiment," Miller said.
"There might have been an organism producing methane or carbon dioxide. But the real kicker is the existence of a circadian rhythm in that data. Every organism that we know of on Earth has a circadian rhythm. It's reasonable to think this holds true for any microbes on Mars," he said.
To help shore up his case, Miller began a campaign earlier this year to find out where old Viking data may be stored.
However, that's when his search down-shifted into a technological time-warp.
It turns out that the policy for maintaining Viking data, specifically in making the bulk of that information electronically usable and accessible, has not been consistently enforced.
"In general, Viking data and data from other missions of that era are very hard to use now. And some are unusable," said Guenter Riegler, Director of NASA's Research Program Management Division.
For example, the data of interest to Miller is archived at the National Space Science Data Center (NSSDC) at NASA's Goddard Space Flight Center in Greenbelt, Maryland. It is captured on some 20 spools of microfiche - strips of film bearing tiny images of raw Viking data.
"There is a certain amount of effort that NASA is going to have to undertake to get these data in shape to be usable," explained Joe King, head of the NSSDC. "To my knowledge, this is the first expression of interest in these particular data," he said.
Riegler said that he has made a decision within the week to move out on rejuvenation of the Viking biology data. "We will proceed to put the Viking lander data from the three biology-related experiments into an electronically usable form," he said.
Microfiche roles of Viking test results, and perhaps old printouts of data sitting in warehouses, are to be digitized. The goal for completing the project is 3 months, Riegler said, costing in the ballpark of $100,000.
There's another reason to dig back into the past for signs of martian life. Given last year's back to-back NASA flops at Mars, old data is as good as it gets.
"We're re-looking at the whole Mars program and may take a somewhat slower approach. Revisiting old, perhaps biology-relevant data is more important now than it might have been a year ago," Riegler said. "We'll provide whatever documentation we can eke out of the archives. Anybody that wants to look at the data is then welcomed," he said.
Viking Labeled Release experimenter, Gilbert Levin, said that Miller's idea about circadian rhythm in martian microbes is an interesting theory. "What's there to lose? We've got time on our hands. We haven't mined those data by a darn sight," Levin said.
Former Viking project scientist, Gerald Soffen, said that while Miller's search for circadian rhythms in the Mars data is a new approach, it will also be a daunting task.
"It is novel, so I can't say it's dumb. But I wouldn't personally want to spend any time on it," Soffen said. It is possible that what Miller views as circadian rhythm may prove to be little more than the effect of temperature swings on the spacecraft and equipment onboard due to Mars' day and night cycles," he said.
Miller remains steadfast in his quest.
"There's only one way to tell. That is to get the data and do the analysis. It wouldn't take much... a month or so. I could tell right away whether there is anything going on or not," Miller said.
