"Best case scenario to be modeled."-Peter Jenniskens

This is mostly a storybook slideshow. So it's pretty entertaining, but not full of meme-able slides.

KEEP MAGNETS AWAY FROM SUSPECTED METEORITES. New rule. Spread the word.

• The slide at 15:00 puts this story in context.
• The bulk of the first half is displaying debris fields of asteroid strikes, on earth, recent.
• Useful TIL at 22:30.
• Interesting physics at 26:50.

So it turns out someone's been running field trips around recent meteor impacts, and this is the results of that project. Pretty good! This video is the science-return for a sweet-ass excuse of a budget request. 

"These samples to the best scientists in the world. To the best laboratories."

Starts at 2:35. Really 11:50. The first stuff is just confirmation of budget. He says they got it. 

This is about the Mars sample return mission. Which is the whole point of the Perseverance mission. Helicopters and "fossils" are all they ever talk about; but Percy is really about radiometric dating. The clog in the Mars pipeline is that the 'resolution' has gotten good enough that law of superposition dating isn't accurate enough. This truly is a snag blocking many research paths. Percy went to a silty buffet table of eroded materiel, some fraction will be radiogenic. So it was a no-lose location. Any samples were going to represent uphill outcrop, fractionally as well as materially, such as zircons. Now a great diversity of samples is sitting waiting to get picked up; while NASA is having a budget crisis. Percy is wasted if Sample Return doesn't happen. This is the actual staff saying all lights look green, and what they are anticipating. 

 "33 minutes is much bigger than 7 minutes."

Starts near 3:00. DART worked great. Flying colors. But planetary scientists must extract all the information they can. Keep in mind there will be a probe called Hera that will get "after" pictures. This panel presentation is what can be figured out with just "before" and "during" information. 

• Pic at 8:30 high res mosaic of Dimorphos surface. Official map of a world. Landmarks are centered where DART hit and rearranged everything.
• 17:00, the impact image, with radiant debris. Cool dust gap ballistic effect.
• 21:40. Splatter flick.
• 26:50. Land observation slideshow.
• Q&A at 30:00

"The idea here is to test the human transportation system"-David Kring

Starts at 6:40. Artemis 2 approaches. It will be a flyby. This is more prelude to Artemis 3, than 2. That will be the next landing. Much of this video is comparisons of scale. It's more of a mission teaser than anything, but it's a well informed teaser.

• Slide at 11:50. Speaker highlights and implies more than he says. Because the lunar south pole is a crater basin, it is exploitable as an eternal cold-trap. 
• 19:15. Previous slides are meant to impress us with topography, but this slide illustrates a point. This intersection of ridgelines, or some other, will decide the ratio of uphill walking to downhill for astronauts. So it's a downplayed big deal. This guy seems to downplay often, intending wit. Probably better teaching for in-person grad-students who are sick of your shit, rather than closed-caption.
• 33:30. He keeps understating things but does a good job of teasing background potential. Lunar selfies will be amazebalz.
• 47:45 The south pole will have rock much older than Apollo samples. Likely older-than-Earth-surface rock.

There is jagged pall among planetary scientists right now. Intense frustration of budgetary stuff. Looking to Artemis sooths it a little. These Artemis missions are vital, and time sensitive since they are supporting the private sector. No progress can come too soon.

"A much more complicated and dire situation than the community realizes."

2023 State of NASA conference from LPSC.

 This is a conference, covering budget and mission status for the fiscal year. Meaning the 2023 plan for every active and scheduled probe. All of them. Major timestamps below.

• Veritas at 10:10
• Percy at 12:35
• Psyche at 14:00
• Clipper at 15:00
• Juice at 16:00
• Artemis at 19:15
• Q&A at 37:20 Note that SueS is the first to protest.

 "The product of implanted hydrogen and helium."-Michelle Thompson

Starts at 2:00.

This is a follow-up of Hayabusa2 sample return. The sample is being studied; what is seen? Turns out bubbles.

• A note for the slide at 5:00. Just so I can refer back to it as a good meme for 'space weathering'.
• Slide at 10:00 has a few reveals for me. I did not know one could measure solar wind exposure in terms of micro deposits.
• Slide at 19:00. I never saw the image she called attention to, the one on the right. Shadow of the spacecraft over the hole it made. That's actually a pretty monumental meme.
• Implications at 41:40.

 "The Martian interior has more complex processes than we previously thought."-Arya Udry

Mars stuff always starts with trying to pin something on the timeline. Gale crater is a Hesperian Crater, that sort of thing. That is what Curiosity is all about, the rest is just fluff. Mars Scientists will shank each other over less studied features. They do not normally. 

This video is thin-slice porn. (22:15)

• Slide at 10:50. Just like Vesta has HED minerals, Mars has SNC minerals. Shergottite, Nakhlite, Chassignite. Three fingerprints of Amazonian mars. If you cut a Mars meteorite in polished-half, this is what you will see. Sand. If it's not sand then the Mars meteorite is probably brecciated, with igneous clasts. Those are the good ones. The ones that can make a reddit geologist offer money. The overwhelming majority of Mars meteorites are SNC.
• Slide at 20:20. Just a beautiful reference slide of some SNC's.
• 36:00 Curiosity has to vaporize a piece of rock, and compare the spectra emitted by the light, against the ratios of SNC and other Mars rocks. If it lazers something with a weird ratio, the rover investigates. These are some of the investigations. 

The takeaway is that Mars scientists really, really, really want those Curiosity samples. Right now. When they appear, igneous clasts will be the harbinger of a time measuring stick. Establishing measuring sticks is central in Mars science at this time. 

 "And there was some other data that suggested they were weathered or very young"-Robert Herrick

When the headlines went around yesterday, I thought this was a followup on the old Venus Express stuff. A second observation of what Grinspoon called hotspots. Sudden thermal spikes, best explained as dragging the thermometer over lava as Venus Express flew over. But no. New flows. Flooowwwwsss. Do you know what you can do with VERITAS and repeat pass radar interferometry of brand new surface flows? A lot. The problem is that we can't be totally certain it's not just a viewing error.

• Slide we've been seeing for the last two days at 4:20 (giggles). Remember with radar smooth means pale and rougher is darker.
• Because the time gap is 9 months apart we have a flow rate!
• Slide at 12:15 comes with a history of why old Magellan data is able to pay off even though it's data from the Beverly Hills 90210 era.
• At 16:40 the slide is showing Maat Mons. We'll be hearing more about Venus' largest mountain. But there are some features that are suspected to be flows coming down, so that's literally what the NASA Venus crew is obsessing over right now.
• Slide at 20:20. Emphasis on how easy it is to screw up radar interpretations to the point specialist debate is mandatory.
• Slide at 25:25 is the computer simulation test. Announcement worthy proof.

As far as I know VERITAS does not carry any special spectrometer. That's DAVINCI's thing, but won't help much on this topic. What VERITAS can do is is get geographical details good enough to imagine field geology a bit. That's what's sinking in to me. There will be a lot of cool modeling, at best. At worst, they might now show their modeling as much as I want to see. For the next decade there will be an uptick in modeling regardless.

 "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.

"And what we found, is not what we expected to find."-Ken Farley

JPL used to have a good monthly lecture called the Von Karmen lecture series. It still exists, but about three years ago they turned to dumpster juice, "discussions", severely dumbed down past the point of not being worth watching. The old ones are still good, though some seem to be missing. Currently however, they seem to be trying to compromise some sort of internal stressor by keeping aspects of the discussion (which inherently are a waste of time and are still a burden on the videos) but have someone actually show up with slides and information. So I'm willing to watch them, and I can tell you where the good timestamps are. 

This JPL however is a "news briefing" video, less risky than the current Von Karmen lectures. This one is from mid-September of this year.

• Skip ahead to 7:13. Just hype prior.
• At 10:00 Ken Farley mentions one of Percy's major finds so far; the Jezero floor is covered in Igneous, not Sedimentary material, implying that the most recent major deposition events in this basin were not water related. "Crystalized from a melt", consistent with one or several impact pyroclastic flows.
• KF also mentions a very important Mars thing... we don't actually know any dates on the ages of things. We can relatively date things, Law of superposition and whatnot. There is plenty of that, but all Mars dates have a ton of error involved currently. We need sample returns to constrain that, and that alone will settle a great many backoffice arguments.
• About 15:50 David Shuster referring to 'wildcat-ridge' mentions that this mudstone bears sulfates, and is salty "possibly in the lake evaporation stage." So Hesperian (because sulfates) and water is depleting. That's no revelation, but the twist is that while this kind of stone is a good preservative of biological organics, as opposed to chemical organics, anything that might be biological is much less likely in the Hesperian.
• Q&A at 37:35.

I have to admit that I personally am a tad frustrated with the Perseverance mission. It may color my impressions, but the Percy crew seems overly focused on astrobiology and tunneling on any organic finds. Organics are everywhere, and not by themselves remarkable. Titan gives no shits about Mars' organics. The sedimentary record is much, much more interesting to me, and the mission happens to be looking at sedimentary rocks, just not talking about them. Sedimentary layers in Jezero should have Noachian stuff included, and no successful missions have touched down on Noachian soil to date. I fear the best discoveries of the Percy mission will come years after it has concluded.

"Permeability is key here."-Suzanne P. Schwenzer 

Skip ahead to 7:00. It's literally dead air up till then.

This video is probing reaction pathways on Mars, to paraphrase it is trying to find exact means by which exact species could live on Mars. 

Astrobiology is a peculiar field. When in the history of history has an 'ology become so robustly staffed long before the first sample is discovered? Such is the red carpet lain before the first alien we can find. Mars isn't among the more habitable places. Remember, 'habitable' for astrobiologists is "can you name a critter that can live there." Mars looks like you could have in the past, Europa however might have life right now and if it doesn't there is almost certainly something from Earth that could thrive there. Venus can't support life at any altitude, but it wouldn't take much investment to get it there. Mars, would take much more investment. Arguably all the frosty ocean worlds could be more habitable than Mars.

This LPI is only looking at Mars and primarily set to ID 'fossils'. Anything that could have lived on Mars had to eat, but what? And had to leave a trail of waste, also unknown. But what is even possible? This LPI narrows it down. 

Our speaker relies heavily on her argument and didn't bring the best slides. The better slides come around 33:10.

• About 34:00, impact sites on Mars are one place where the heat to drive life could be after the very beginning era of Mars. But not in the middle of the crater. At the lowest places, where liquid could pool and the basin could be permeable. This will also Apply to Titan and the Dragonfly mission.
• 39:40 She doesn't really call it out that I noticed, only because her assumed audience would already know it, but the chemicals she names have enough chemical energy to drive some sort of metabolism.
• 40:40 the slide is... not showing you outright, but proving the chemical reaction paths that microbes could capture energy from. 

All planetary scientists have come to note that Mars history is very episodic with a background trend of cooling. In other words Mars climate change has been constant cooling, no decadal period had the same habitat. However in local environments, say an old melt-dyke, or an impact crater (Gale craters development is wholly explained using the heat of impact alone,) you really could have a stable environment for a while, centuries, and this LPI is showing that you could have the food too.

 

In honor of Artemis 1's successful launch this new Apollo to Artemis video came out. It features three speakers who had direct involvement with the Apollo-17 mission. Harrison H. "Jack" Schmitt was an astronaut on that mission. He is joined by Charles "Chip" Shearer and Clive Neal who have been analyzing Apollo samples.

This video is setting up expectations for Artemis. It's coming from the perspective that what we can do with samples has advanced considerably, thus you can taste the hunger these people have for new Artemis specimens.

Artemis-3 will be the first Artemis to collect samples. After Artemis-4 sample return will only increase in priority.  

"55 new minerals"-Chi Ma

Chi Ma's name shows up on a lot of papers but it's hard to find video of him speaking, so this LPI is that much more interesting for me. This LPI involves a lot of electron microscopy, which is why his name come up a lot, he has the keys to some of the best electron microscopes. But the big takeaway is, there's going to be a lot of fascinating images in this talk.

• Benitoite at 5:50 with barioperovskite inclusions. 
• At 10:50 he presents a table of the new minerals discovered from one ancient meteor. He calls modest attention to the high amount of Titanium in the new minerals. Keep in mind, Ti is formed by supernovae, is lightweight and super reactive. The reason it is so strong and flexible is because it's so reactive that once it bonds to itself it never wants to let go, but it bonds to anything just as readily. So the Ti in the protoplanetary disk would have reacted early and often to make any odd mineral. In other-words Ti is fully expected in making primordial minerals that don't normally recur since. If you find a weird mineral with Ti in it when normally there would be none, it's very old.
• At 33:05 a tiny meteor from Mars yields nine new minerals. As popular as Mars news is, this got no press.

I kinda wanted to make a bullet point for every new mineral and every pretty thin-slice, but they came multiple per slide and he was going through them so fast that was impractical. Suffice to say he categorically listed many of the new minerals as the bulk of the lecture. Rock hounds and mineralogists should get chained nerd-gasms. 

"All of our known meteorites fall into clusters when you analyze their cap-17 oxygen [and other isotope ratios]"-Megan Newcombe 

Skip ahead to 15:00. That block is all production jazz that should have been edited out. (And for some reason the closed captioning wasn't set up either.)

Isotopic deduction is kind of an abstract thought. It is in fact very objective, but it's hard to picture. It's a bit unintuitive. It's easy to underestimate, because when you see what can really be done with it, it's almost like magic. Isotopic deduction is to planetary science what spectroscopy is to astronomy. A fount of hard facts. That's what this LPI is about.  

• 18:30 the matrix of Chondrites is volatile rich. This is the kind of fact one could easily just try to pocket without thinking through. The cement holding most asteroids together has volatiles in it. Any place that can get hit with an asteroid can therefore receive diverse volatiles.
• From 20:20 for two slides she physically separates asteroids into two groups, literally physically separated in the proto-cloud by proto-Jupiter or maybe by proto Earth and Venus, though the latter case implies both formed further out.
• Slide at 21:10, what she's doing with her graph is showing you that water and heavy water (Deuterium or "D" is a heavy hydrogen that when mixed in H₂O is heavy water.) are constant in ranges of the solar system, therefore she can just use that ratio to prove that Earth got it's water from a certain range out from the Sun. Turns out the range is about where our orbit is now erring on further out. The case that Earth and Venus were further out seems to be building.
• The catch, at about 32:00, is that there is a second match, enstatite meteorites match the same isotopic profile, but could have worked closer to current orbits. 
• To figure out which happened she looks at a mineral that is semi-metamorphosed and tries to find the point of metamorphosis where water couldn't have stayed on Earth.
• 49:40 "So we coat it in gold."

Much of the remaining is exhaustive methodology and results. Normally I would call attention to those results, but she manages to get very specific about multiple topics. How big a planetesimal can hope to hold onto water? What could they be made of? Turns out she can deduce hard answers, and eliminate old guesses. 

"Boy, did we learn a lot from 21, almost 21 and a half kilograms of rocks and soils."-James W. Head, III

https://www.youtube.com/watch?v=jyXAHHM1Pp4

Artemis is rolling out to the pad again about now, and will have Nov 12-17 to pick a clean launch. Never forget that aborted launches count as test results, each one makes the new rocket system stronger. 

This LPI is a 50 year anniversary of Apollo spoken by an Apollo OG geologist; a good teaser for Artemis. Our speaker had Artemis in mind when he prepared this lecture. 

• 16:15 "We wanted to go to rough areas because geology scales directly with surface roughness." Maybe I should have used this quote in the header. It also relates well with Artemis. 
• 17:20 I've never heard of anyone dunking on a fool with this feat. The second Apollo mission,12, aimed for a previous probe and took pictures with it. Eat that conspiracy jerks.
• 20:50 sample 14321, has an inclusion that may be ejecta from Hadean Earth. Possibly molten Earth. 
• 27:25 The story of the seat belt basalt. These kinds of Amy Shira Teitel stories are fun.
• 33:10 Apollo 17's Jack Schmitt did an LPI already set up.
• 35:15 Another thing I never knew. Proposed drivable rover.
• At 39:10 he transfers into specifically Artemis preview. When he points to a geological map and says "it's all here" what he's implying is that Artemis missions will categorically explore each color-zone on the map. 
• About 53:00, he's straight up telling us Artemis behind the scenes stressors.

by Gil Scott-Heron

A rat done bit my sister Nell.
(with Whitey on the moon)
Her face and arms began to swell.
(and Whitey's on the moon)

I can't pay no doctor bill.
(but Whitey's on the moon)
Ten years from now I'll be payin' still.
(while Whitey's on the moon)

The man jus' upped my rent las' night.
('cause Whitey's on the moon)
No hot water, no toilets, no lights.
(but Whitey's on the moon)

I wonder why he's uppi' me?
('cause Whitey's on the moon?)
I was already payin' 'im fifty a week.
(with Whitey on the moon)
Taxes takin' my whole damn check,
Junkies makin' me a nervous wreck,
The price of food is goin' up,
An' as if all that shit wasn't enough

A rat done bit my sister Nell.
(with Whitey on the moon)
Her face an' arm began to swell.
(but Whitey's on the moon)

Was all that money I made las' year
(for Whitey on the moon?)
How come there ain't no money here?
(Hm! Whitey's on the moon)
Y'know I jus' 'bout had my fill
(of Whitey on the moon)
I think I'll sen' these doctor bills,
Airmail special
(to Whitey on the moon)

Don't forget to vote.

 Mandatory Mars: Ordered list of top-ten lectures to learn about Mars.

The following lectures are directly or indirectly focused on Mars. The first few are more fundamental and the last few are more conclusive. Altogether one can get a very good idea for what we have learned about Mars over the last decade. 

They aren't ranked in order of "best", but in an order that should deliver a satisfying learning experience.

1.                                                           
2. 
   
3. 
   
4. 
   
5. 
   
6. 
   
7. 
   
8. 
   
9.                                      
   
   
   
10.                                       
    
    
    

"The CV and the CK chondrites are so similar that they've been describes as a clan"-Tasha Dunn

https://www.youtube.com/watch?v=UHtlCWAi4EI

This LPI is about tracking certain small meteorites back to a parent body. For example more than half of all asteroids are fragments of Vesta. Other asteroids must be fragments of something else right? It's actually common, one vestoid may have been broken into smaller pieces for example. 

The way you find out is either backtrack the orbits and see if they merge, but that only works for something recent and flying in a noticeable cluster. Or you collect a bunch of meteorites and see that some of them are similar, and guess that they may have come from a common parent body. That's what this LPI is about. 

• Our speaker is an undergrad teacher, and as such she builds her argument from a more fundamental level than a professor free of a class schedule would. That's great for us, she spends the first half of the lecture explaining everything one needs to understand the second half of the lecture using beautiful and intuitive slides. I think they speak for themselves and need no highlighting from me.
• The meat of the lecture starts around 12:20. This is where she starts transferring away from background.
• Slide at 17:55 is when she starts the question of if CV's and CK's came from the same parent asteroid. 
• At 20:20 she demonstrates the dilemma. One parent body or two, either has redox problems.
• At 23:55 she shows a sample that may be a transitional phase between the two and therefore support the one-parent-body path. Most of the remaining lecture is interrogating this premise.
• At 44:15 the argument is complicated. 
• Conclusions at 45:05.

I find the Late Heavy Bombardment, and any kind of early bombardment fascinating. So many things seem to hinge upon it. So many asteroids, trojans, and the like seem to be fragments of it. I wonder how many Mars-sized objects there really were, or if there were more Vestas. Taking meteorites from the ground and getting a thin-slice is the primary tool we have to look into such things, so it's no surprise that progress is slow. Maybe one day we will know the origins of each large asteroid though.  

"The presence of liquid water was not all that long in terms of the full geological history."-Shannon Curry 

This LPI is about atmospheric loss on Earth, Venus, and Mars. The methods for finding those rates are headache inducing, but if you have the skills then the details you need to recreate the research are in here. 

• Slide at 1:45 our speaker defines a few categories of how atoms escape their planet. She uses the term Jean’s Escape, which just means hotter, lighter molecules escape more regularly than heavy and cold molecules. 
• At 3:35 Venus’ ion escape is highlighted. The greater the solar wind, the more Venus builds an induced magnetic field, thus slowing the erosion rate. However the ionic pressure of solar-wind protons still picks up any negatively charged atoms they come into contact with, so the slowing is weak yet turbulent. 
• Slide at 7:00, photo-chemical escape is dominant on Mars, largely because the two oxygen's in carbon-dioxide are essentially exposed. When a heavy molecule tries to escape Mars, it usually does, and Mars cannot recollect it as easily as Earth and Venus can.
• At 10:10 the most important part in my opinion, the method they use to predict past atmospheres is tricky. One can’t just scale the current rate back in time to get the old atmosphere. Certain assumptions are taken on and the modelers know they won’t all work out. The bottom line is extrapolating old atmospheres is an active field that has a long way to go. 
• Slide at 11:25, Mars must have been losing the lions share of it’s peak atmosphere over only the Noachian. You can’t wind it back from anywhere near were it is at anything close to it’s current rate of loss. The climate of Mars would have been cooling noticeably year to year as soon as Mars was solid. 

This lecture is just a bit older than the Phosphine announcement, so she doesn’t yet know of the upcoming probes heading to Venus. I was really happy to find this lecture again, I saw it when it was recent and often would refer to it, but couldn't recall detail enough to find it in LPI’s archive. When MAVEN concluded it’s primary goals they did a team press conference where all the investigators had a bit, and I think Curry was one of them. Our speaker Curry by the way is the current PI of MAVEN while Jakowsky was the original one. That talk (which I swear was a Von Karmen lecture) seems to not exist anymore but it was the best MAVEN report I saw. Much of the content in there recurs about three years later in this lecture. 

"And this opens a new field for the study of nuclear synthetic anomalies"-Ke Zhu

This LPI is using the relative abundances of Chromium to infer some details about what kinds of minerals were abundant in the very early solar system proto-planets. Ureilite and Aubrite meteors are often speculated to be of Mercury origin, or otherwise a protoplanet that has since been destroyed and the majority of its debris consumed in other planetary bodies. Chromium isotope dating is great for us because 3.7 million years is a pretty modest margin by astrogeology standards. 

• At 10:00 a nice overview of early chondrites
• At 15:00 he goes into the chondrules components. Some of the eldest bits known.
• At 23:30 he starts going over rocky worlds, Earth, Vesta, and Mars.
• At 46:20 he touches on the origins of Phobos and Demos as ejecta, which is widely accepted though still a bit of a secret. Chromium dating supports. 

I really like isotopic dating but I have to confess relative abundances of isotopes puts me straight to sleep. This lecture took me a minute to get though, but the good side is that it really was a thorough disclosure for those who better my attention span. It's perfect for those with aptitude for this kind of chemistry. The relevance of course is fundamental. Employment for isotopic dating is now and will continue to be in high demand. 

"40% of the gold that's ever been mined in the history of humanity."-Matthew S. Huber 

https://www.youtube.com/watch?v=R0icEsOcyO8

This LPI is referring to an impact crater in South Africa, Vredefort, one of the three largest known basin forming impact craters on Earth. The lecture emphasizes not gold or mining specifically, but rather structures called granophyre dikes. Dykes are vertically shafted magma, often infiltrating a crack or two strata layers; a chimney or wall of igneous stuff that is younger than the stuff around it, and also a channel for magma to reach the surface. These dykes are not volcanic, but melt from impact energy. Most of it pools, but some fingers of that molten pool reach under the impact producing these dykes.  

• At 1:15 along with a nice slide demonstrating a theme pops up, craters can be infused with ore. Gold ore in the case of Vredefort. 
• At 3:55 he explains the importance of these granophyre dykes. They are all that's left to study of the post-impact molten pool. 
• At 4:30 he shows a pretty slide with inclusions in the dyke. The inclusions have a lot of pattern and structure, this lineated form that implies the dyke was flowing in a particular direction when liquid. 
• At 12:30 he shows inclusions of a different kind, inclusions of a previous melt, implying that the material re-liquified at some point. 
• At 14:25 he starts proposing answers to all the questions he's been trailing.

Huber is a good speaker. I've seen him a few times before and his pacing and detail are somewhat refreshing to my attention span, though he can put a disinterested student to sleep.

Think about this, this gold-ore bearing impact was big and certainly not a gold nugget. The melt described in this lecture represents a mix of native and impact material, and that impact material must have been old. Gold is formed only in supernovae, so this impactor likely was older than Sol. Large and older than Sol implies that the primordial disk involved many large things, some bearing ore. 

Now apply the idea to worlds like Callisto and Mars. How many ore bearing impacts did they catch? Impact basins may be the only places a prospector can expect to find ore. For deep inside Callisto, the ice pulverized debris may settle in a lump or spread out to dilute the salinity so that each fragment separates from others. In Mars case, it may be more Earthly, but with similar dykes dropping more and longer roots.