November 20, 2024 – 7:29 a.mReading time: 2 min.
A German scientist claims a NASA mission may have destroyed evidence of life on Mars. What it’s all about.
The search for life in the universe fascinates not only astronomers, but also laypeople. Who hasn’t looked at the night sky and wondered if there was another species out there?
Even if it is almost impossible that there is life other than terrestrial life in our solar system, that does not mean that there never was any. One planet in particular has been the focus of research for a long time: Mars. People are constantly looking for traces of long-ago life on the “red planet”.
But as a German scientist now explains in a commentary in the journal Nature, a Mars mission could even have wiped out life on this planet. The thesis of Dirk Schulze-Makuch, head of the astrobiological research group at the TU Berlin and chairman of the board of the German Astrobiological Society, refers to a NASA mission in 1976.
The two space probes Viking 1 and 2 explored the surface of Mars and examined the planet for signs of organic life. Since very little was known about Mars and the conditions there at the time, experiments were carried out in the same way as they were carried out in laboratories on Earth, says Schulze-Makuch.
For example, soil samples were supplied with water and nutrients. They then looked for signs of metabolism or growth. The assumption was that microbes could be “activated” in this way. However, the experiments did not produce any results that indicated life.
But perhaps this was not because there was no life to be found, but rather because it was destroyed by too much water, as Schulze-Makuch suggests. The experiments involved working with temperatures and amounts of water that did not correspond to the conditions on Mars.
According to Schulze-Makuch, it is possible that microbial life on Mars does not rely on liquid water, but rather uses hygroscopic salts to extract moisture from Mars’ thin atmosphere. These salts are present in some regions of Mars and could support life specifically adapted to these extreme conditions.
The scientist draws a comparison with microorganisms in hyperarid, i.e. extremely dry, regions on earth – for example in the Atacama Desert in Chile. These are adapted to extreme drought and can even be damaged by sudden water supply. These creatures also use hygroscopic salts to obtain and store moisture.
If his assumptions are correct, it could be that people have been looking for life on Mars in the wrong place. Instead of just “following the water,” which has long been NASA’s strategy, one should also “follow salts to find microbial life.”
How has our understanding of Mars evolved since the Viking missions, and what modern techniques are being used to search for extraterrestrial life?
Interview: Time.news Editor and Dirk Schulze-Makuch
Editor: Good morning, Dirk. Thank you for joining us today. You’ve stirred quite a debate with your recent claims regarding the Viking missions. Can you sum up your thesis for our readers?
Dirk Schulze-Makuch: Good morning, and thank you for having me. Essentially, my thesis suggests that NASA’s Viking missions in the 1970s may have inadvertently destroyed evidence of potential life on Mars. The methods employed during those missions may have been flawed due to our limited understanding of the Martian environment at that time.
Editor: Interesting! You mention the Viking 1 and 2 probes which were the first to explore Mars’ surface. What specific experiments carried out could have led to this destruction of evidence?
Dirk Schulze-Makuch: The Vikings conducted experiments on soil samples by providing them with water and nutrients to look for signs of metabolism. The assumption was that Martian microbes—if they existed—would respond similarly to terrestrial life. However, the very act of introducing these elements could have altered or even obliterated any existing microbial life or indicators of such.
Editor: That’s fascinating and a bit concerning! When we consider today’s technological advancements, do you believe we could approach the search for life on Mars more effectively now?
Dirk Schulze-Makuch: Absolutely. We’ve learned tremendously from the Viking missions. Current missions now utilize more sophisticated methods, with a better understanding of Mars’ unique conditions. For instance, we can analyze subsurface materials and utilize equipment designed to detect traces of life more delicately, without the risk of contamination that earlier missions faced.
Editor: You indicated that even though the search for extraterrestrial life captivates many, it’s unlikely we’ll find it within our solar system. Why do you think that is?
Dirk Schulze-Makuch: Well, while Mars was once potentially habitable, the conditions today are far harsher than what is needed for life as we know it. Furthermore, environments like the icy moons of Jupiter and Saturn present more promising conditions for surviving life. The search is continuing, but the solar system presents limited venues where biological life could have flourished.
Editor: Would you say that we’re perhaps looking in the wrong places, or at least, we should expand our search beyond Mars?
Dirk Schulze-Makuch: I think it’s critical that we explore a variety of locations beyond Mars, such as Europa and Enceladus—both of which hold subsurface oceans that could harbor life. In fact, the pursuit of astrobiology shouldn’t be limited to just one planet; each celestial body offers unique insights and potential clues.
Editor: Moving on, in your commentary, you referred to the public’s fascination with the search for life in the universe. How important is public interest and engagement in such scientific endeavors?
Dirk Schulze-Makuch: Public interest is paramount! Science thrives when the public is engaged, as it brings attention and funding into these explorations. It ignites discussions not just among scientists but society as a whole, prompting a deeper appreciation for our own planet and its place in the cosmos.
Editor: Thank you, Dirk. Your insights provide a thought-provoking perspective not only on the Viking missions and Mars but on the broader implications for our quest for extraterrestrial life. Before we wrap up, what’s next for you in this field of research?
Dirk Schulze-Makuch: I’m currently involved in several projects that study extreme environments on Earth as analogs for extraterrestrial conditions, as well as participating in upcoming missions aimed at other celestial bodies. The future of astrobiology is bright, and I’m excited to be a part of it!
Editor: We look forward to hearing more from you in the future. Thank you for your time, Dirk!