Exploring Titan with Rotorcraft

[SelfSim]

Dragonfly mission to Titan announces big science goals

From the paper:

NASA's Dragonfly mission will send a rotorcraft lander to the surface of Titan in the mid-2030s. Dragonfly's science themes include investigation of Titan's prebiotic chemistry, habitability, and potential chemical biosignatures from both water-based "life as we know it" (as might occur in the interior mantle ocean, potential cryovolcanic flows, and/or impact melt deposits) and potential "life, but not as we know it" that might use liquid hydrocarbons as a solvent (within Titan's lakes, seas, and/or aquifers).

Science Goals:

Our science goals include determining how far prebiotic chemistry has progressed on Titan and what molecules and elements might be available for such chemistry.

This misssion seems destined to confuse Titan's chemistry (whatever it is), with what we call 'pre-biotic chemistry' here on Earth. After all, its not 'prebiotic', unless there's extant signs of life in that given environment, (which seems very much like putting the cart before the horse in the case of Titan's geo-chemical environment?), so:

Importantly, we will search for chemical biosignatures indicative of past or extant biological processes. As such, Dragonfly, along with Perseverance, is the first NASA mission to explicitly incorporate the search for signs of life into its mission goals since the Viking landers in 1976.

I hope to still be around to see what happens.

I still think the rotorcraft is quite a risky rover, given that:

And while the science team doesn't expect rain during Dragonfly's flights, Hayes noted that no one really knows the local-scale weather patterns on Titan—yet.

(Hayes is co-author and a science team co-investigator).


Comments?

 

[Mark Quayle]

Dragonfly mission to Titan announces big science goals

From the paper:

Science Goals:
This misssion seems destined to confuse Titan's chemistry (whatever it is), with what we call 'pre-biotic chemistry' here on Earth. After all, its not 'prebiotic', unless there's extant signs of life in that given environment, (which seems very much like putting the cart before the horse in the case of Titan's geo-chemical environment?), so:
I hope to still be around to see what happens.

I still think the rotorcraft is quite a risky rover, given thatHayes is co-author and a science team co-investigator).


Comments?

Hope it has some way to tell us about the weather before crashing.

 

[SelfSim]

Hope it has some way to tell us about the weather before crashing.

Looks like it has an atmospherics sensing package, called 'DraGMet':

DraGMet is an extensive set of instruments measuring 11 distinct properties: atmospheric temperature, pressure, wind speed and direction, methane humidity, hydrogen partial pressure, crustal seismicity, electric field, surface dielectric properties, surface temperature, and ambient sound.

If they use it in real-time during a flight and it fails mid-flight for some reason, it may actually bring on that crash!?

 

[1rreducibly Complex]

Titan seems like a sub tier option. If I remember right, europa has conditions better suited to sustaining life. Which makes it the better prospect for exploration.

Volcanic flows would be the most likely candidate for organic chemistry. We know microbes on earth use chemosynthesis to sustain themselves near hot areas of volcanic activity. That is the most likely form of life to be found in our solar system, outside of earth.

I agree labeling it "pre biotic" chemistry is premature. The temperature range on both titan and europa may not fall into a range that can support any form of life. There could easily be no organic compounds (or precursors of organic compounds) to be found anywhere.

 

[SelfSim]

I agree labeling it "pre biotic" chemistry is premature. The temperature range on both titan and europa may not fall into a range that can support any form of life. There could easily be no organic compounds (or precursors of organic compounds) to be found anywhere.

Pre-biotic is the term they need to be careful with, (IMO).
There's already evidence of large organic compounds however, (in the case of Titan, by Cassini, I believe). The paper says:

Even larger and more complex atmospheric molecules, with molecular weights of thousands of Daltons (Da), have been detected but not resolved (Coates et al. 2007, 2009; Waite et al. 2007) due to instrument limitations. These atmospherically produced organics coalesce into haze particles that then settle out to cover much of Titan’s water-ice bedrock {followed by nine published references!}

Organics of thousands of Daltons are quite massive molecules. What they actually are, is still a mystery though.

 

[FrumiousBandersnatch]

Hope it has some way to tell us about the weather before crashing.

They should give it a methane-proof umbrella that can unfurl in case of rain....

 

[Mark Quayle]

They should give it a methane-proof umbrella that can unfurl in case of rain....

Or come up with a methane energy source, a funnel in case of rain.

 

[SelfSim]

The rotorcraft, Dragonfly, weighs about half a ton and will fly abount only once every (Earth) month. They're not expecting any rain in the chosen landing area.

In terms of looking for life as we know it (LAWKI), and life as we don't know it (LAWDKI), they propose the approach shown in the attached table (I hope its readable). I like how they've already started calling measurements for LAWDKI 'Signatures' of hydrocarbon based life, (as if that's already been decided)?

 

[SelfSim]

I notice also that they persist in searching for Chris McKay's speculated distribution differences in molecule types (by mass) between abiotic vs biological. Here is his figure describing it:


This contrasts with a recent published paper (here) which uses molecular complexity as the basis of distinguishing between the two. Their following distibution graph, unlike McKay's back of the beer-coaster made up one, is based on actually tested samples. Notice the broader distribution of the biological species in comparison with the the dead/abiotic/inorganics one.

This comparison of distributions, appears as being completely different, even the opposite of McKay's speculation(!), yet McKay's is what they're assuming in the Dragonfly (rotorcraft) design paper!?

 

[SelfSim]

The 'MA number', (the horizontal axis in the second graph above), has been derived from the firmly established theory of assembly pathways. Assembly pathways are sequences of joining operations that start with basic building blocks, (in this case molecular bonds), and end with a final product. In this instance, it ends up being a simple integer representing the smallest number of steps required to construct a given organic molecule.

Molecules with high MA are very unlikely to form abiotically, and the probability of abiotic formation goes down as MA increases. So, if a high MA molecule is detected on Titan, it would likely be a result of some kind of analog to the more ordered earthly biological process.