WILLIAMSBURG – Fifty years ago this summer, NASA’s Viking 1 and Viking 2 became the first spacecraft to successfully land on Mars — touching down July 20 and Sept. 3, 1976, respectively — marking a milestone in the search for life beyond Earth. Scientists hoped the missions would find signs of life, but the results appeared to rule out that possibility. Findings from NASA’s Phoenix probe, a 2010 scientific paper and a journal article published in February renewed questions about the possibility of life on Mars.
On Friday, Sept. 18, William & Mary’s Sadler Center will host a symposium honoring the 50th anniversary of the Mars Viking landings, with talks from NASA scientists, a look at historical photographs and discussion of the future of Mars exploration.
“[We] will have an opportunity to hear the exciting results that there may be life outside the Earth,” said Joel Levine, a former NASA scientist who worked on the Viking mission, now a research professor at William & Mary. “It has implications for applied science, biology, chemistry, physics, geology.”
The Viking landers performed scientific experiments, including three life-detection experiments. The experiments worked by feeding nutrients into the soil and looking for metabolic products produced as a result.
“If there are living microorganisms in the soil … the one thing we know is that they would eat nutrients, if you supply nutrients,” Levine said.
At the time, only one of the three experiments yielded results that indicated possible life on Mars, while the other two showed no organic molecules present in the soil.
However, NASA’s 2008 Phoenix probe called this into question, with findings that when the Mars soil is heated up, it releases chlorate gas.
“In all the Viking experiments, we had to heat up the sample,” Levine said. “We didn’t know that in 1976, by heating up the sample of soil, we are releasing this very chemically active chlorine oxygen compound, called chlorate. And that chlorate is so chemically active, it would destroy any organic molecules that were there.”
In 2010, chemist Steven Benner wrote a paper stating the reason organics weren’t found in 1976 was that the testing method had unintentionally destroyed them. Benner came across the findings while at the Lunar and Planetary Institute in Houston, which led him to believe the original Viking findings were incorrect.
In February, Benner published an article in the scientific journal Astrobiology about Viking’s legacy and findings. He has also written a 416-page book called “Meet the Neighbors: Life on Mars and How to Find It.” While the book isn’t available in the U.S., the college intends to have imported copies on Friday for him to sign.
“This is the first public discussion of the fact that there is evidence, according to Steven Benner, that there’s life on Mars,” Levine said.
Benner’s talk will be one of six, including Under Secretary for Science and Research at the Smithsonian Institution, Ellen Stofan. Levine will be moderating the symposium and giving the final talk on future Mars exploration.
Levine said the symposium was originally set for NASA Langley Research Center in Hampton on July 20 — the 50th anniversary of the Viking 1 landing. But new security protocols implemented last September meant only those with security clearances could attend if the event stayed at Langley. That wasn’t what Levine and co-planner Tom Young — who was Viking’s mission director and former director of NASA’s Goddard Space Flight Center in Maryland — had in mind. So, he went to W&M’s Applied Science department chair, Eric Bradley.
“I said, ‘We have this great cast of speakers and we can’t do it there at NASA because of new security protocols, so let’s do it at William & Mary,'” Levine said.
Each panel will include a question-and-answer portion for audience members. The event will also be livestreamed, with talks posted on the school’s YouTube page afterward. The symposium will be held in the Commonwealth Auditorium from noon to 5 p.m. The symposium is free and open to the public.
“For the first time, we have evidence that suggests there may be present-day life elsewhere,” Levine said. “Not extinct life, but active life, so that affects everything from science to religion to business.”
