Detecting Martian Life: How Can We Find Evidence of Slow Life on the Red Planet?

[Frabjous]

https://bigthink.com/hard-science/accidentally-killed-life-mars/

Interesting article about a type of life that might exist on Mars. It brings up questions on how do we test for the existence of life.

 

[Astronuc]

It brings up questions on how do we test for the existence of life.

To get a detailed profile of rock textures, contours, and composition, PIXL’s maps of the chemicals throughout a rock can be combined with mineral maps produced by the SHERLOC instrument and its partner, WATSON. SHERLOC – short for Scanning Habitable Environments with Raman & Luminescence for Organics & Chemicals – uses an ultraviolet laser to identify some of the minerals in the rock, while WATSON takes closeup images that scientists can use to determine grain size, roundness, and texture, all of which can help determine how the rock was formed.

https://www.jpl.nasa.gov/news/signs-of-life-on-mars-nasas-perseverance-rover-begins-the-hunt
https://mars.nasa.gov/news/8678/the-detective-aboard-nasas-perseverance-rover/

Apparently instruments look for signatures of organic compounds. Ostensibly amino acids, or perhaps constituents.

https://mars.nasa.gov/news/8678/the-detective-aboard-nasas-perseverance-rover/

The team will also be looking for astrobiology clues in the form of organic molecules, which among other things, serve as potential biosignatures, demonstrating the presence life in Mars' ancient past.

https://mars.nasa.gov/news/8863/searching-for-life-in-nasas-perseverance-mars-samples/https://www.nasa.gov/feature/goddard/2022/dig-deep-for-evidence-of-martian-life

https://www.jpl.nasa.gov/news/how-n...ade-first-detection-of-organic-matter-on-mars

The organic molecules found by the team also have chlorine atoms, and include chlorobenzene and several dichloroalkanes, such as dichloroethane, dichloropropane and dichlorobutane. Chlorobenzene is the most abundant with concentrations between 150 and 300 parts-per-billion. Chlorobenzene is not a naturally occurring compound on Earth.

The articles are frustratingly unclear on what 'organic compounds' the systems are detecting, other than the last article. The articles mentions organic, e.g., "Organic molecules are the building blocks of all known forms of terrestrial life, and consist of a wide variety of molecules made primarily of carbon, hydrogen, and oxygen atoms." I would look for nitrogen (amino acids).

https://mars.nasa.gov/news/1767/nasa-rover-finds-active-and-ancient-organic-chemistry-on-mars/

 

[russ_watters]

Thread reopened. Musta been a bug on the windshield. It's been cleaned off.

 

[tech99]

I recall James Lovelock, creator of the Gaia hypothesis, saying that he attended a meeting about the search for life on Mars at NASA in the early days of space exploration, and biologists were expecting to find an animal like a camel! He suggested right from the start that the technique should be to sniff the atmosphere for respiration products.

 

[russ_watters]

I recall James Lovelock, creator of the Gaia hypothesis, saying that he attended a meeting about the search for life on Mars at NASA in the early days of space exploration, and biologists were expecting to find an animal like a camel! He suggested right from the start that the technique should be to sniff the atmosphere for respiration products.

People (even experts) can head off in weird directions when given a problem way outside their comfort zone. I'm reading Michael Collins's book and he has a lot of not so nice things to say about flight surgeons/doctors with regard to their extreme concerns about astronaut health in the early days of the space program. The astronauts on the other hand, seemed not to. It may be because as fighter/test pilots they were used to spending time at very wrong g's and correctly figured that extended time at 0 g wouldn't be a big deal.

 

[DaveC426913]

The astronauts on the other hand, seemed not to. It may be because as fighter/test pilots they were used to spending time at very wrong g's and correctly figured that extended time at 0 g wouldn't be a big deal.

I wonder if it has more to do with the disparity in goals and measures of success.

A test pilot knows he is at risk, and likely figures "Every time I didn't die was a success"; whereas a doctor's philosophy is "They can't die even once or my career is toast".

A pilot measures the past; a doctor measures the future.

Who was it whose launch got delayed and they hadn't counted on his bladder? So he soiled himself and did the suborbital flight sitting in his own effluent.
Pilot and doctor would have very different ideas of success.

 

[PeroK]

People (even experts) can head off in weird directions when given a problem way outside their comfort zone. I'm reading Michael Collins's book and he has a lot of not so nice things to say about flight surgeons/doctors with regard to their extreme concerns about astronaut health in the early days of the space program. The astronauts on the other hand, seemed not to. It may be because as fighter/test pilots they were used to spending time at very wrong g's and correctly figured that extended time at 0 g wouldn't be a big deal.

That reminds me of the case of the first two climbers to summit Everest without supplementary oxygen: Reinhold Messner and Peter Habbler. I believe a lot of medical opinion was that it would be impossible, or result in permanent brain damage. They did it despite the warnings.

 

[russ_watters]

Who was it whose launch got delayed and they hadn't counted on his bladder? So he soiled himself and did the suborbital flight sitting in his own effluent.

The first one.

 

[berkeman]

Who was it whose launch got delayed and they hadn't counted on his bladder? So he soiled himself and did the suborbital flight sitting in his own effluent.

Technically he "wetted" himself, not "soiled". Jeeze. And he had permission...

https://clip.cafe/the-right-stuff-1983/request-permission-relieve-bladder/

 

[TeethWhitener]

It brings up questions on how do we test for the existence of life.

Isotope analysis is generally the way to go. Living things process different isotopes of common elements in ways that lead them away from equilibrium values. Carbon-12 is generally enriched in living things because it makes bonds that are ever so slightly weaker than carbon-13, and so it’s a little easier energetically for life to build up and break apart complicated molecules. Same thing for N-14/N-15 and O-16/O-18, all of which can be measured to extremely high precision.

Incidentally, about a year and a half ago at a conference I stumbled into a fascinating talk on “slow life,” microbes that had been brought up from kilometers beneath the ocean floor. Their metabolism had slowed by orders of magnitude over the eons of their evolution, to the point where enzymatic turnover frequency was measured in weeks rather than fractions of a second. It brought to the forefront of my mind just how challenging the search for extraterrestrial life might end up being. The life in these microbes on earth is barely detectable and we know what we’re looking for here. Imagine how difficult it will be to detect life in the much harsher conditions on Mars where their metabolic reactions might be measured in years instead of weeks.