Will Drilling Find Extant Life on Mars? (Issue #21)

by: Nicole Willett

blog 21 family portraitI recently attended the online NASA/JPL Mars Exploration Program Analysis Group (MEPAG) meeting that was held on July 23, 2013. The meeting’s purpose was to discuss the Mars 2020 rover and many other Mars exploration issues. Many people wonder why NASA keeps sending rovers to Mars without stating that they will unequivocally search for extant life. The term extant means, still in existence.   We know that MSL Curiosity has the equipment to detect life and that Mars 2020 will have many of the same instruments. However, Jack Mustard, Brown University professor, who presented at the MEPAG meeting, stated, “To date, the evidence that we have from observations of Mars and Martian samples is that we don’t have the clear indication that life is at such an abundance on the planet that we could go there with a simple experiment like Viking [had] and detect that [life is] there.” Mustard went on to explain that it makes more sense financially and scientifically to search for past life instead of current life. He believes that we must continue studying the past geology of the planet in order to better understand whether past life existed on Mars.

As we anxiously await the analysis from Curiosity’s second drill sample, which was taken on May 20, 2013, we can discuss the search for present life on Mars. As indicated above the Mars 2020 rover will not search for extant life. Some people do not understand why we must wait seven years to launch a rover similar to MSL with a sample return cache that will sit on the planet for an unknown period of time with no plan as to how it will be returned to Earth. However, there are other missions planned for Mars which may search for and possibly find current life on Mars. Two such missions are ExoMars and the Icebreaker Life Mars mission.

blog 21 exomarsExoMars is collaboration between the European Space Agency and the Russian Federal Space agency. It is a mission that includes an orbiter and lander planned for 2016 and a rover with a drill that can reach two meters beneath the toxic surface, planned for 2018. The 2018 mission objective is to search for past or present life on Mars. During the MEPAG meeting, the question was asked, “What if ExoMars finds life, and how will that affect Mars 2020?” The answer was given by Jim Green, Director of NASA Planetary Science, who stated, “It would be a great problem to have.”  This also started a discussion about whether this would be a “Sputnik moment” and possibly encourage a new race for humans to Mars.

The Icebreaker Life mission could also be funded for a 2018 launch under the Discovery/New Frontier program, a separate funding scheme like the 2016 Insight mission. In a paper published in the journal Astrobiology on April 5, 2013, Dr. Chris McKay, Dr. Carol Stoker, and other leading scientists stated, “The search for evidence of life on Mars is the primary motivation for the exploration of that planet. The results from previous missions and the Phoenix mission in particular, indicate that the ice-cemented ground in the north polar plains is likely to be the most recently habitable place that is currently known on Mars.” The goals of the Icebreaker Life mission include:

“(1) Search for specific biomolecules that would be conclusive evidence of life.

(2) Perform a general search for organic molecules in the ground ice.

(3) Determine the processes of ground ice formation and the role of liquid water.

(4) Understand the mechanical properties of the Martian polar ice-cemented soil.

(5) Assess the recent habitability of the environment with respect to required elements to support life, energy sources, and possible toxic elements.

(6) Compare the elemental composition of the northern plains with midlatitude sites.”  [Source: http://online.liebertpub.com/doi/abs/10.1089/ast.2012.0878 – Journal Astrobiology 4/5/2013]

This mission is very similar to the Phoenix lander but will have more advanced scientific equipment, including a drill that will reach a meter below the surface, an instrument called the Signs of Life Detector (SOLID), an Alpha Particle X-ray Spectrometer, a Wet Chemistry Lab, and many other instruments. This combination of instruments may potentially alter how we view life in the universe. The SOLID instrument has the ability to detect compounds with a biological origin such as whole cells and complex organic molecules.  It has an advanced digital camera and what is known as a “lab on a chip” that can perform various chemistry tests using equipment the size of microchips. The technological advances being made are greatly improving the field of robotic exploration and experimentation in ways never thought possible in the past.

DCIM100GOPROThe Icebreaker Life mission will search for biomarkers in the same region near the north pole of Mars where the Phoenix Lander executed its mission in 2008. A biomarker is any molecule that indicates the presence of life, such as an enzyme.   These biological molecules carry organic biochemical information. The Icebreaker drill is capable of drilling one meter into the subsurface of the Red Planet in order to search for biomarkers. The ice shavings retrieved from the drill would be analyzed for molecules that are too complex to be present from a non-biological source. It is important to drill below the surface in order to retrieve samples that have not been exposed to the radiation and perchlorates (salts) that exist on the surface of Mars. The radiation and perchlorates could potentially destroy any biomarkers or biological material present, hence the importance of a subsurface mission.

Many opinions exist regarding the search for life on Mars, past or present. The sheer number of planned missions is a clear indicator of the widespread scientific interest. When asked about the search for life on the Red Planet, McKay stated, “Why search for a second genesis of life? The implication is that life is common in the universe.”

[Images: NASA, ExoMars, Astriobio.net]