Biomarkers

What makes this biomarker significant in the search for life?

We all know that water is essential for life as we know it. It acts as a critical solvent catalyzing biochemical reactions, which could indicate previous or present habitable conditions on Mars.

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What is the most likely source of this biomarker on Mars?

Water has been found on Mars at the polar ice caps, and there is probably more in ancient reservoirs and aquifers under the surface. Dr. Pascal Lee also mentioned that once you reach about 2-5 km below Mars’ surface, you could potentially find liquid water.

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What missions and technologies (past, present, or future) investigate these biomarkers?

There have been several missions concerned with finding water on Mars.NASA’s Phoenix lander found water ice at the Martian poles. The Mars Odyssey also detected hydrogen signatures indicating the possibility of subsurface ice deposits. Furthermore, the Mars Reconnaissance Orbits used radar to identify subsurface lakes.

What makes this biomarker significant in the search for life?

Silicone is an interesting biomarker as it can technically replace carbon in structural frameworks in life forms under very specific conditions - however the Martian landscape might actually be conducive for this.

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What is the most likely source of this biomarker on Mars?

Silicone is one of the most abundant elements on Mars. It likely arises from geochemical reactions between silicates, water, and other elements on the surface of Mars.

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What missions and technologies (past, present, or future) investigate these biomarkers?

The Curiosity rover ended up studying silica-rich minerals, and with future proposed Mars Sample missions, the use of advanced spectrometry could be used to better identify the potential role of silicone on Mars.

What makes this biomarker significant in the search for life?

Methane is an interesting potential biomarker as it is a byproduct of living organisms. It’s also a byproduct of geochemical processes, so research needs to be done to determine whether the presence of methane on Mars is biotic or abiotic. However, the amount of methane on Mars fluctuates indicating some form of active replenishment.

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What is the most likely source of this biomarker on Mars?

If not biologically produced, the source for methane on Mars likely are forms of subsurface reservoirs or geochemical reactions between water and certain rock types, however we’re not sure.

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What missions and technologies (past, present, or future) investigate these biomarkers?

The Mars Express orbiter first detected methane in the Martian atmosphere in 2004. Later, the curiosity rover measured spikes and declines in methane with a tunable laser spectrometer. ExoMars is to map the distribution of methane and isotopic composition to hopefully be able to differentiate between biotic and abiotic sources.

What makes this biomarker significant in the search for life?

Amino acids are the building blocks of proteins. If we were to find amino acids, that could be an indication for biological processes possible on Mars. Furthermore, if we were to find new amino acids, that would be an indication of alien life.

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What is the most likely source of this biomarker on Mars?

Amino acids could result from abiotic processes involving reactions of molecules with water, likely subsurface. It is speculated that perhaps amino acids could also have arisen from meteorites or comets.

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What missions and technologies (past, present, or future) investigate these biomarkers?

The Mars Organic Analyzer (MOA) would use a microchip capillary electrophoresis system with the ability to detect amino acids. Perseverance is currently searching for samples with potential amino acids, and ExoMars would be equipped with instruments to explore for subsurface samples containing amino acids.

What makes this biomarker significant in the search for life?

Made up entirely of fused rings of hydrogen and carbon, these stable molecules can be formed either via biotic or abiotic processes - if the latter being the case on Mars, PAHs could prove to be an indication of some ancient life on Mars as they are precursors to organic compounds like amino acids and nucleic acids.

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What is the most likely source of this biomarker on Mars?

PAHs are found all throughout the universe, and also on Earth in the burning of fossil fuels and heavy industry processing. They can also be detected in organic matter resulting from volcanic explosions and forest fires. PAHs were detected on Martian meteorite ALH84001, and while later determined that any PAHs were more likely the result of earthly contamination, it sparked the search for further biotic PAHs on Mars.

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What missions and technologies (past, present, or future) investigate these biomarkers?

Martian Meteorite ALH84001 used laser desorption/ionization mass spectrometry (LDMS) to detect PAHs. Missions like Curiosity have also explored organic molecules using chromatography-mass spectroscopy. Future missions like the ExoMars rover plan to use drilling to search for these compounds sub-surface.

What makes this biomarker significant in the search for life?

Nitrogen is a key component of amino acids and nucleotides, both essential for life as we know it. Nitrogen found on Mars could potentially serve as an indication for ancient microbial life.

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What is the most likely source of this biomarker on Mars?

Nitrogen was probably not formed via biological processes on Mars, but rather detected nitrates on Mars probably came from lightning storms or meteorite impacts.

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What missions and technologies (past, present, or future) investigate these biomarkers?

The Curiosity rover detected nitrates on Mars using SAM (Sample Analysis Mars) instruments such as mass spectrometers and gas chromatography. Missions such as Perseverance and future mission ExoMars plan to continue exploring the nitrogen compounds underneath Mars’ surface.