While the demand continues to bring bits and pieces of Mars back to Earth for extensive studies, scientists are also devising tools and technologies that can be sent to the Red Planet for field investigations of life. Could these low-cost methods usurp the early need for samples taken directly from Mars?
This choice brings to mind the comment of Marcel Proust, the French novelist, literary critic, and essayist who wrote the novel. In search of lost time“The true voyage of discovery is not to seek new landscapes, but to have new eyes.” In order to discover past life on Mars, a sample return program would be best, but if we want to discover current life on the Red Planet, doing so with instruments on Mars is the way to go.
This is the view of Dirk Schulz-Makuch, professor of astrobiology and planetary habitability at the Technical University of Berlin in Germany. In addition, it is believed that currently available methodologies are suitable and advanced enough to determine whether there was life on Mars.
“However, in order to get unambiguous results, we have to put a combination of these methodologies together,” Schulz-Makuch told Space.com.
Related: NASA's turbulent Mars sample return mission has scientists seeing red
Mysterious chemical activity
Schulze-Makuch points to NASA's twin Viking landing missions in the 1970s. It was a great time to try to answer a provocative question: Is Mars home to life?
While biology experiments have revealed unexpected and mysterious chemical activity in Martian soil, the majority of Viking Mars investigators have leaned on the lack of clear and conclusive evidence of microorganisms in the soil near the landing sites.
It could be said that the Vikings landed the Twins an act Respond to the Life on Mars question by replying: Can you repeat the question?
“In principle the Vikings' approach was correct,” Schulze-Makuch said. “The problem at that time, almost 50 years ago, was that our methods were not yet sophisticated. We did not have a good understanding of Martian environments. We had made great progress in both respects,” the astrobiologist said.
It's hard to explain
It is true that with the return of the Mars sample, scientists can apply more of our most advanced methods, including those that are not yet available for a space mission, Schulz-Makuch said.
But given the long period of time it takes to sample a soil — both on the surface of Mars and during the long distance from Mars to Earth — “we are likely to find only organic remains of possible life, which will be difficult to explain.” “This approach will work well for past life on Mars, but if our goal is to find existing life, an in situ mission is the way to go,” Schulze-Makuch said.
“There is an inevitable tension in returning a Mars sample and searching for life,” said Chris McKay, a space scientist at NASA's Ames Research Center in Silicon Valley, California.
“Clearly the best research on life will be done on samples in laboratories on Earth,” McKay told Space.com. “But the prospect of bringing back a sample that might contain Martian life gives a lot of people pause, and it's already been banned, and some would say banned, before.” [United Nations] Outer Space Treaty.”
Can we assume based on Viking's findings that there is no life on Mars?
“My answer to that is yes and no,” McKay replied. Mars Researcher highlights data collected by Viking in 1976, NASA's Phoenix lander's discovery of perchlorate in 2007, as well as analysis by the still-functioning Mars rover Curiosity that showed low levels of organic matter since landing in 2012.
“Most Mars scientists confirm that the reaction seen in Martian soil is a chemical reaction and there is no surface biology now. So yes,” McKay said. “But no. This opinion is not unanimous,” he said, citing the state of life on Mars and the possibility of discovering it through the launch experiment called “Viking.”
McKay said NASA and the Committee on Space Research (COSPAR), an interdisciplinary scientific body, consider any sample returned from Mars a potential biohazard.
MacKay said he argued in publications that “the standard of evidence for achieving scientific consensus is clearly lower than the standard that should apply to precautionary protection of Earth. Life may not be the scientifically preferred explanation for this problem.” [Viking Labeled Release] The results, however, cannot be ruled out yet.”
Public opinion or legal action likely “will not support the assumption of no life on Mars for the purposes of a sample or an astronaut's return to Earth without further analyzes on Mars, regardless of scientific consensus,” MacKay concluded.
One potential NASA mission that has received support is the Mars Life Explorer (MLE). This deep-drilling lander will focus on searching for signs of life currently existing on the Red Planet.
The MLE received a strong endorsement from the latest Planetary Science Decadal Survey, a report by the US National Academies of Sciences, Engineering, and Medicine released in April 2022.
The toolkit at MLE is designed to be “machine agnostic,” said astrobiologist and MLE “science champion” Amy Williams, an assistant professor in the Department of Geological Sciences at the University of Florida in Gainesville.
“There are combinations of instruments that already exist that could fly with the proposed MLE, or new instruments and technologies that are currently maturing and could be replaced,” Williams told Space.com. “There are very real opportunities for alternative and new tools to join the mission.”
In the meantime, research teams are taking a pioneering role in the SOLID project (“Signs of Life Detector”), work carried out by the Spanish Center for Astrobiology. There's also a microfluidic life analyzer, or MILA, developed at NASA's Jet Propulsion Laboratory.
Or how about building a tool for use during robotic ice mining missions, a high-tech device to search for today's thriving Martian life?
This approach is being implemented by Steven Benner, founder of the Applied Molecular Evolution Foundation and Firebird Biomolecular Sciences LLC.
In fact, the Agnostic Life Finder Association (ALFA) was created, with both Benner and Jan Spachek, inventor of the Agnostic Life Finder (ALF), as leading members.
“The only way to achieve the ALFA Mars goal is to screen for life on Mars before the first humans land there.” Association website Announce.
So, in the end, it seems that the predictions of “whether life exists on Mars or not” remain hazy with patches of uncertainty.
Revisiting Carl Sagan's famous words that “extraordinary claims need extraordinary evidence,” astrobiologist Schulz-McCoch's view is that “based on our current understanding of Mars, I believe that… Unusual claim It is that Mars has no life and never had any. We should finally go and find out!”
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