https://www.nasa.gov/press-release/nasa-finds-ancient-organic-material-mysterious-methane-on-mars
Very cool news! To be clear, they didn’t find life – organic material, in this case, refers to compounds containing the element carbon, which can be produced by life or by natural chemical processes. But it’s a good sign for life or past life, possibly, on Mars.
Well, they didn’t find life because NASA has never included tools that could directly image single cell life forms of microfossils. It’s almost like they’re trying hard not to.
Perhaps someday they will do this, but they don’t seem to have any plans to.
It isn’t like it would be easy to do.
False alarm: It was all just Matt Damon’s farts.
Ewwww, potato farts!
Nifty! Incredible news! I love this kind of stuff.
“It might only be a particle of preanimate matter.”
Not really. Although the general public associates the term “organic” with “alive” or “natural”, from a geochemical standpoint it just means compounds with a carbon base and other elements (often hydrogen, oxygen, and nitrogen). That such compounds form by natural non-alive processes is entirely expected because carbon is the third most abundant chemical element by mass in the universe and readily forms single and double bonds with itself and most other chemically reactive elements. Virtually any environment with a dense collection of elements that has enough energy and at a temperature at which chemical bonds can form will produce a wide variety of organic chemical species. We even find complex species such as aromatic hydrocarbons and amino acids are found in the interplanetary medium and from response spectra in planetary nebulae, indicating that they occur spontaneously even in the harshest environments that chemisty can occur in.
There are all manner of mechanisms that might produce methane on Mars that have nothing to do with life, although the fact that complex organic molecules are pervasive and the lack of any special chemistry or unique properties for life on Earth would seem to suggest the potential for abiogenesis to occur spontaneously with great frequency in any environment meeting some energy threshold. Although Mars is the most “Earth-like” of all other planets in the solar system, its surface environment is incredibly harsh to any form of life we would recognize; between the ultraviolet radiation, the lack of a protective magnetosphere, the near-vacuum condition, caustic perchlorate salts in the soil and the “liquid” slurries of infrequent surface water (recurring slope lineae), and lack of bioavailable nitrogeneous compounds, nothing on Earth could inhabit Mars for long enough to reproduce. This doesn’t mean that Mars could not host life, but it would likely be very simple, almost certainly subsurface, and would have to have as-yet unknown energy cycle that is not based upon photosynthetic organisms. Since Mars has no geothermal activity, this would almost certainly have to be some kind of chemisyntheic mechanism which converts chemical compounds created non-organically by sunlight into an energy chain, none of which has been observed or even credibly hypothesized.
This complaint hews close to the popular conspiracy theory that NASA is trying to cover up the existence of extraterrestrial life for some reason. In fact, it could not be further from the truth. Although the Mars Science Laboratory (MSL or “Curiosity”) does not have an instrument for scanning electron microscopy, the reason for that is practical rather than conspiratorial, and it simply boils down to the fact that Curiosity is jammed as full of instruments and handling devices as the engineering team could make and provide energy for. An additional device to not only use a compact SEM but also handle and prepare samples would put the scientific package way over budget (both weight and power), and while looking for signs of life, past or present, is one of the objective of the MSL mission, it is far from the only one. The primary goal of the mission is to learn more about the planetary environment and geology, which is what the scientific instrumentation package is designed toward.
The likelihood of finding of any fossils on the surface is pretty remote (notwithstanding the difficulty in preparing samples for examination) especially given the planetary-wide dust storms that tend to move and abrade surface structures. Mars is tectonically inert and has not experienced active volcanism for tens or perhaps even hundreds of millions of years (although there are speculations of more recent volcanism), and the landing locations of Mars landers or rovers look for relatively safe planar geographies which will ensure mission success, so being able to look at samples from layers billions of years ago when Mars may have had an environment more amenible to life as we would recognize it is not realistic for the MSL, and in fact would require either drilling tens or hundreds of meters or a very risky precision landing in a rift valley or deep crater. And it isn’t clear that we would even recognize any kind of “microfossil” evidence of non-terrestrial life if we saw it as it may look vastly different from life on Earth. Looking for the chemical traces of life, which CheMin and SAM can do, gives a greater chance of finding something novel than just looking through random surface samples of dust or rock.
For anyone who wants to learn about the actual engineering and capability trade studies on Curiosity, I highly recommend reading the recent The Design and Engineering of Curiosity: How the Mars Rover Performs Its Job by The Planetary Society Senior Editor and “Planetary Evangelist” Emily Lakdawalla. She covers the various trades on mission capabilities and budget restrictions (including a near decapitating descope after CDR) in Chapter 1, an extensive discussion of the Sample Acquisition, Processing, and Handling (SA/SPaH) system in Chapter 5, and a detailed description of the capabilities of each of Curiosity’s chemistry instruments (Chemcam, APXS, CheMin, and SAM) in Chapter 9, as well as a summary of what has been discovered by the MSL mission.
Stranger