"There are two little planets that I call weenie beans here; Mercury and Mars."-Vicki Hanson

Skip ahead to 7:45.

It's always a good sign when a speaker opens up with something very very basic. That usually means something eschewed is about to get called into question! In this case the spoiler is the premise that the lithosphere is not an atmospheric layer of a convecting planet. From Convections point of view, it is.

This is more of a panel than a lecture, it involves a lot... of corny humor. They might be stoned, but are probably nerds doing public speaking in a room full of people they know. There aren't a lot of slides, but there are a fair number of quotes to timestamp by. It's a very good proof of what the actual Venus scientists are thinking and doing. These are they.

•  Hansen actually says a lot of noteworthy bits. Like she's been teaching undergrads via short blurbs for years and years. "What was Earth like before plate tectonics? We would like to know." At 15:00. That sums up her talk nicely.
• Slide at 16:58, this slide illustrates the point of view shift, Venus crust is just a conductor between two convective forces therefore its just like an air-filter, collecting chemistry between the two convective forces. A very ergonomic point of view within the limitations of what actual probes can actually do.
• At 18:00, "Most of the planet sits at the same elevation." A sound bite that is more on point than the slide it comes with. Her style is a very interesting, very auditory way to teach. I'm personally bad at auditory learning.
• 22:10 "A lot of the Soviet missions to Venus were great successes while the missions to Mars were failures, and the converse was true for the US,[so from early on we were building on...'the history']." From a different panelist.
• 29:14 "If you cooked off everything on the Earth, everything on the surface gets put into that atmosphere."
• 31:50"[Venus had a resurfacing event] and when it did this it churned up a lot of materiel into the atmosphere."
• 32:50. Note that the new term "Tessera" meaning the continent-like highlands of Venus, has now entered the vernacular. "We think those are the ancient rocks on Venus, that will help us tell about climate." He's talking about granite. It's buoyant among basalt, and we do not know how so much of it appeared so quickly in the crust of Earth. Any granite detection will be a huge deal. Better than Aliens.
• 36:16 "Right now there is some debate as to whether Venus is in a stagnant-lid, or mobile lid regime."
• 50:33 "What is the actual chemistry of a lava on the surface?" Note that this question is disclaimed, as in the coming probes can't help much. But this is what they are fighting over behind the scenes.

The Phosphine thing isn't in this video at all and there are reasons for that. SOFIA didn't see any, so the topic is in a state of 'it must be episodic, or localized or not at all.' which is directly related to the "actual chemistry of lava." You see why that is going to be the long-term Venus conundrum. The big TLDR of this video is that the word "Tessera" is going to be used a lot more from now on.

 "If you look at this sort of picture that I drew."-Nick Borsato

Skip ahead to 4:50.

I like this guy; he speaks to my level. Belt'n out facts that might be obvious if I could be bothered to infer things.

I have to admit I don't have near the same interest in exoplanets as in planetary science, but I would be interested in any planetary science of exoplanets. That's what this video delivers. It's quite a bit more satisfying than it looks.

• I feel like the slide at 8:50 should be a meme.
• At 10:58, he's really good at selling his samples.
• The theme of the remaining talk is to categorically list all the measurable information that can conclude something. So it's a good reference. 
• Summary at 43:25.

This talk seems to have ulterior motives, homeboy may be applying for a grant. Nobody ad-libs this much salesmanship; but they do talk extemporaneous this way. Best wishes if he is, good talk regardless. 

In American history, the nineteen hundreds, when life was moving so fast no one had anything in common with their parents or their children; this is what East Coast defunked-urban life was.

 "It's already making beeping sounds at me." -Oliver White

Skip ahead to 3:40. 

Dear god Oliver White is a caricature of Oxford. Aside that, just seeing this video pop up and my first thought was "Charon shine." The reflection off of Charon to illuminate the dark side of Pluto is Charon shine, and it was hoped it would be enough to illuminate the dark side to get some imagery. That was just post flyby, and I've not heard about it since.

As expected of a geological map proposal, this video is packed. It may be the best reference to anything Pluto related for a long while to come. There's at least 2 slides in here that are worthy of being wall-hangings. 

• At 9:45 The Haze-lit, space seems to be the only result of waiting for Charon-Shine images. They would have been dim anyway as one can imagine.  
• Slide at 12:00 has two good looking maps shown without the nitrogen glacier/heart, but it's the map at 10:40 that we've been waiting for.
• At 13:30, a graph showing the first-I've-ever-seen-it six geological periods of Pluto's history and their names. They are dated by crater supposition, so it's just a scale of 'Older or Younger' then a specific crater, not, by chunks of measured time. The heart-lobe crater named sputnik is the oldest and therefore the first divider of eras. 
• At 32:30. This RTS, a ring of rifting around Pluto longitudinally, and seemingly of the bedrock stuff of Pluto, the hard water ice. Similar to Tethes. These global features come up a lot but with variable circumstances. For example Charon has a canyon all the way around it's equator. Longitudinal is a new variation.   
• At 35:00, Sputnik mountains seem to be described as tumbling, brecciated, blocks. That's a new one.
• At 41:45, He presents his argument that the paleo-RTS is an equatorial feature from before Pluto got knocked over by the Sputnik impact.
• Thoughts at 49:45

 It's a romanticized introspection, as a nihilistic dirtbag smears himself across the smears Europe.

That's a full spoiler of the plot, but not of the book.

 The Europan trans-crust cable.

The Europa Clipper is the most exciting probe, so far, in the search for extraterrestrials. Some people don't seem to know why. Why not send a lander? A flyby probe in orbit of Jupiter is not very flashy, surely Europa Clipper is overrated.

Europa's crust is estimated to be 10.7 km thick. A nice submarine probe that can drop in and swim will have to burrow through that and hopefully have some range left when it gets through. 10.7 kilometers is a good estimate; but no engineer in the world would set to work without a much better estimate. They don't want to make a cable plus or minus half a kilometer. Any fraction of a meter is a big deal to those who have to make and launch it. Communication between the depths of Europa and Earth is going to require a hardline. This IMRAD is about what the tether will have to be capable of. Europa Clipper must locate an ideal place for the tether and the future probe that uses it.

In the introduction many hardships are discussed. Among those not already mentioned, faulting, tidal flexing, communication angles, cold, and thermal gradient, increasing pressure, salinity, and refreezing after melt. 

There is a lot of interesting engineering nuance in the methodology section. Fiberoptic tethers have known properties such as how they stretch and how signals degrade over distance. Detailed illustrations for each test come with. This is effectively the meat of the IMRAD and there is a lot of it. For example, if the tether is suddenly pulled on by an Europaquake, accounting for pressure and cold, will it snap? The results section is obviously the results of each of these engineering tests. I didn't read anything crazy in the results, but the images are really cool.

In the discussion the first thing to note is that the tether for sure is expected to make the ice more unstable at that point. It's safe to say now that if a failure in the ice happens near the tether, it will be at the tether. How effective the long tether communicates was a little vague, but it's safe to say a reinforced tether will outperform a minimalist tether. The tether itself can be used at a sensor, glitches in communication can infer stuff about stress and temperature, and even fault vectors along it's length.

If you stretched the tether at all, it was permanently damaged. How brittle the ice is at a given temperature will depend on salinity. I didn't see any finicky points about tether length, probably in large part because Europa Clipper hasn't told us what that length should be yet. 

Chronology; Mars vs The Moon

Who's surface is older? Who's oldest? The smart bet is on Callisto, but you never really can tell. It could be Venus, but not Venus's surface. That is clearly young. The chronology of the early solar system is a puzzle to which pieces are constantly emerging but most remain missing. Earth is older than The Moon, we can say that, but how old is Mars really? Is it smaller in part because it started later? Because Jupiter ate all it's food? Solid bets, but still unknown. 

Mars is actually dated 4.1-3.7 bya semi-officially, Luna (The Moon) is dated 4.41 bya. Callisto? actually just 4.0 bya but the number is little more than a placeholder. We know more about Mars and Luna, but even still we don't know enough to be certain that Mars is younger. These numbers have a large amount of uncertainty in them, but just like we can be sure that Earth is older than Luna, and Callisto is younger than Jupiter, this IMRAD will take a step toward determining the eldest between Luna and Mars.

In the introduction we find that dating by crater counting is actually limited to 3.92 bya. That explains why the dates for Callisto and others bunch up at around 4. You need secondary evidence to go older, and that comes mostly from superposition and modeling. An old thing overwriting some of another old thing by superposition means that the overwriter is older, and if you can figure out how much older then you get a range. Luna is used as a baseline in all crater counting. As you would guess there's a lot of nuance included in that since we don't actually know if Luna is an ideal baseline. The environments in the solar system vary too widely. 

Here's a problem; Mars actually has way too few big impacts compared to Luna. There's obviously something amiss. Compared to Luna Mars should have 40 big ones, Mars actually has 7, and the seventh is debatable. Smaller-big craters actually deliver the expected ratio where Mars has a lot more. Part of the issue is that even 40 is a small number to statisticians and this kind of research is heavily reliant on statistical math. It could have something to do with Jupiter, it could be that Luna was hot and squishy and really good at exaggerating how big a thing hit it. Could be all of that and more. 

The paper strait-up skips to results before methods, because their results are pretty straight forward and brief. "The observed Mars number is significantly smaller than the scaling would predict." Meaning Luna is either older, has/had some property that makes big craters, or maybe Mars is bad at catching impactors. But for sure Mars got hit less. 

Now the methods. As promised, small number statistics put an umbrella of uncertainty on all this. A subtilty the team peppered all over the paper is that the squishy factor, whether Mars or Luna was hot at the time of impact is currently testable. Some of the radiogenic isotopes usable for dating exist somewhere in a hard-drive, both worlds have seen probes. And there is probably other data that could confirm or eliminate the possibility of any squishyness. Someone could be researching this right now.  

In the discussion the emphasis is that Mars and Earth do not catch the same number of impacts today, not even close. So obviously the time of big impacts probably had two wildly different environments. Keep in mind we don't actually know the positions of either Earth or Mars at that time, which really puts a hard drag on the ratio of Luna vs Mars even meaning what we want it to mean, aging. 

In the end this IMRAD caught an interesting imbalance and aggravated the questions that came up with it. It didn't make any hard claims other than Mars got hit less than Luna. But questions as to the reasons why are defined clearer now, so the research process continues with better focus.