Moments before the first spacecraft to touch Martian soil landed on the red planet in 1976, you could hear a pin drop in the Jet Propulsion Laboratory in Pasadena, California.
One of the people in the room waiting for the Viking lander to touch down was Patricia Ann Straat Ph.D., who now resides in Sykesville. The biochemist in 1970 joined the team that would successfully land the first spacecraft on Mars. She was co-experimenter of the Labeled Release life detection experiment and a member of the biology flight team.
Straat in January self-published a book, “To Mars With Love,” about her experience. In it, she details the six years leading up to the Viking landing. Although the results of the life detection experiment have been published many times, Straat said her book is the first to tell the story of the trials and tribulations that got them there.
“It was 5:12 a.m. on July 20, 1976, and we all stood in stunned silence staring at the now still screen,” Straat writes in the first chapter. “I felt sick in the pit of my stomach. Surely the lander had come in too fast for a soft landing. It must have crashed.”
Straat became a part of the Viking Biology Team after interviewing with Gil Levin, then-president of Biospherics Inc. He had been awarded a contract from NASA to send a life detection experiment to Mars, she said.
When Straat took the job, she wasn’t confident the lander would even hit Martian soil, let alone find evidence of life. Some of her colleagues at Johns Hopkins University, where she worked prior to joining the Viking team, advised her against the career change.
“Well, I decided, you know, it sounded like an awful lot of fun,” Straat said. “I was confident that if it was a total bust, that somehow I'd land on my feet.”
To determine whether there was life on Mars, Straat and the biology team designed an experiment to test Martian soil.
“Living creatures on Earth, including soil microorganisms, consume organic material and exhale carbon dioxide, a gas,” Straat said. “If the organic compounds are ‘labeled’ with radioactive carbon, the resulting carbon dioxide will also be radioactive.”
On Mars, once the Viking landers collected Martian soil and radioactive organic compounds were added, the landers monitored the head space above the soil for the evolution of radioactive gas, according to Straat.
It was a success.
But they could not yet say they found life on Mars. They had to run another test to prove the radioactive gas was caused by biology, and not a reaction caused by chemical factors in the Martian soil, Straat said.
The biology team did this by taking a second sample of the same soil and heating it to 160 degrees centigrade to sterilize it, then running the same experiment, she said. Heating the soil should destroy microorganisms living in it, according to Straat. Therefore, if no radioactive gas evolved in the pre-heated soil, that indicated the reaction in the first test was biological, Straat said — and that’s exactly what occurred.
They publicized the results, but their findings were met with skepticism.
Other scientists offered alternative, non-biological explanations for the results, according to Straat.
“I was pretty skeptical myself,” she said. “Saying that there’s life on Mars is a pretty big statement. And you want to be careful.”
So they ran another experiment on Mars. This time, they pre-heated the soil to 50 degrees centigrade and ran the test again.
“There aren’t too many chemicals that are destroyed by 50 degrees centigrade, but we would expect Martian organisms to be affected by 50 degrees centigrade because Mars is much, much colder than Earth,” Straat said. For comparison, the human body is 37 degrees centigrade, she said.
The 50-degree sterilization temperature reduced the positive response by about 70 percent, which the biology team said was “very strong evidence” for biology, according to Straat.
Many scientists have tried to replicate these results using various chemical agents, but none have succeeded, Straat said. The results of the mission indicated a detection of microbial life on Mars, though the results are considered controversial to this day, according to Straat.
On NASA’s website, the Viking Project is described as the first U.S.-led mission to land a spacecraft on Mars and transmit images back to Earth. Of the biology experiments, it states, “Conducted 3 biology experiments to look for possible signs of life and discovered chemical activity in the Martian soil.”
Seventeen years would pass before NASA sent another vessel to Mars.
Straat noted that while NASA has sent spacecraft to Mars to search for signs of conditions that would support life, Viking was the last mission sent to search for life itself.
‘It had to be told’
Straat invites readers to come to their own conclusions about the Viking Project by reading her book.
She worked off and on for about 40 years writing the book, then pushed herself to complete most of it in six months after she was diagnosed with a serious illness.
“It is such an exciting story," Straat said. "It had to be told. I would have been very angry with myself if I died before I wrote the story.”
The book can be purchased at www.tomarswithlove.com. The story also includes memories from Straat’s life outside of Viking. When she wasn’t working 15 hours a day, Straat spent time with horses in Maryland or explored the beachside communities of California.
The 83-year-old has accomplished much in her life. She majored in psychology during her undergraduate studies at Oberlin College in Ohio, then took her first chemistry course in her senior year and fell in love with it. Straat also enjoyed biology, so she put the two together and pursued a Ph.D. in biochemistry.
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“I went to Johns Hopkins and talked to the head of the biochemistry department and talked my way in as a graduate student. You could do things like that back then," Straat said with a chuckle.
After getting her doctorate, she went to Hopkins Medical Complex, now the Johns Hopkins Bloomberg School of Public Health, and spent four postdoctoral years in the department of radiological sciences. Straat served as an assistant professor for two years in that department before going to work for Levin.
After Viking, she went on to work for the National Institutes of Health, from which she retired in 2001. Straat held many positions there, including science administrator and chief of the referral system.
Since retiring, marketing the book has been like a full-time job for Straat, she said.
“It’s such an important experiment, even if it didn’t discover life on Mars," Straat said. "It’s how it got there. Nobody else has told anything about how it got there. They just talk about the results. And how it got there is a really interesting story … and it needs to be preserved.”
Straat’s home is full of memorabilia from the Viking days, some of which is featured in her book. She has albums full of photos and stacks of data. The data, of course, is meaningless to anyone without Straat’s knowledge. Columns of numbers fill the pages.
When Straat passes away, these pieces of space exploration history will go to Johns Hopkins, she said, “And not a day before.”