Recap: Global aurora widely distributed around mars due to its complex multipole magnetic field. When coronal mass ejections of plasma arrive at Mars, especially those with a "frozen in" magnetic field oriented a certain direction, the response of the Martian system is losing atmosphere through two losses: 1) "Pickup ions", ionized atmosphere picked up by the solar wind's electric field (this also happens at comets) and 2) simple momentum exchange of solar wind (mostly hydrogen ions, aka protons) with the heavier elements of the martian atmosphere. I recently calculated the Jean's Escape time for H2 vs. CO2 in the Martian environment, and H2 escapes significantly faster, by many orders of magnitude. So the Jean's Escape mechanism is an additional thermal effect that when in combination with the two solar wind related loss mechanisms can definitely explain Mars's thin skies.
All this because Mars lacks a magnetosphere, and we believe that its electromagnetic internal dynamo died at least 3 billion years ago, due to heat loss, as measured in crustal magnetic fields (or actually the lack thereof) near ancient craters. AS I CANNOT REITERATE ENOUGH, the lack of a global magnetic field on Mars is one of the most daunting technological challenges to colonization. We could generate local magnetic fields, but it would require many new novel engineering techniques so as to prevent devices from malfunctioning near the field's (very high field strength) source.
Also, we already knew all of this, and screw you, MAVEN, because you barely beat our contract anyway, and I've moved on to new and better mistresses.
Yay NASA. So...what happens when Earth's magnetic field flips again? Apparently a friend of mine did the upcoming cover of Science that depicts this phenomena. Neat.
While I have you captive in my own post's comment section... I recently met with someone pretty businessey on the forefront of commercial space tourism (no, it wasn't Musk, people, sorry). I asked him whether or not there were certain engineering regulations his company is considering to minimize space pollution in anticipation of imminent regulations. He told me that the commercial space accident/life insurance providers would have enough incentive to clean up the low earth orbit debris cloud. I'm not so sure how to crunch the numbers when human life is in the equation, so I guess this is where quantification breaks down and we have to defer to qualitative analysis, which of course pits human life against free market Keynesianism, just like usual. What are your thoughts on regulatory vs. laissez-faire incentivized space pollution cleanup efforts?? P.S. any help from the business-minded comment-reading lurker is appreciated. No, seriously, anyone, feel free to demolish my concerns with an argument. Also, ButterflyEffect, I would like to add to francopoli's reply that yes, the Earth's magnetic field changes polarity orientation on average approximately every 500,000 years, and that as best we can tell, we're overdue for a flip. Paleomagnetism suggests that it's been 720,000 years or so since the last magnetic field inversion, so we assume that we're about 220,000 years overdue (of course francopoli is always right). And indeed, it is happening, the Earth's magnetic moment (overall field strength) has been declining for at least the last 200+ years, ever since we started keeping tabs on it. The reversal takes place on timescales of thousands of years (francopoli is right again), not instantaneously on winter solstice, 11:11:11 AM of 12/21/2012... which would have been infinitely more badass, naturally. I also agree with franc that our technological abilities are now far outpacing the engineering challenges presented by magnetic field reversal, so it will essentially have been planned for long before it happens. wasoxygen, I would love to discuss the economics of this with you in the arena of your choosing.
Yep. I remember back in '07, when I started watching the sun, and was excited to experience solar cycle 24 (which we are currently in the post-maximum decline of), and yeesh, is it a dud. The space weather forecasting people keep playing the "you'll be sorry in the future" card, but no one's listening. I think they're right. Even if we're entering a new solar period of extreme quiet (Dalton or Mauder-like or totally different) we'll eventually need to incorporate orbital boosting technology to combat increasing atmospheric drag and a power grid that can withstand relatively large currents induced by geomagnetic storms. In related news: I'd wager that soon we limit searches for intelligent life to "habitable zone" planets with radio emissions from characteristic plasma processes that are indicative of a healthy magnetosphere. That's an issue of sensing resolution that tech can potentially resolve in the not-too-distant future. Also, there's been that recent press release of the deeper layers of the ocean temporarily storing heat, and they will eventually reintroduce it into the atmosphere (as the ocean and atmosphere are thermally coupled systems).
It's not just deeper levels. You start to see lasting high pressure systems and suddenly you have surface level blobs pop up that have a ton of stored heat because they hadn't been losing it to the colder atmosphere over however long a time span. This example alone has been partially responsible for unheard of weather patterns in the northwest.Also, there's been that recent press release of the deeper layers of the ocean temporarily storing heat, and they will eventually reintroduce it into the atmosphere (as the ocean and atmosphere are thermally coupled systems).
Doesn't it make sense that H2 would escape much faster than CO2 or any heavier compounds that are in the atmosphere? It seems intuitive that Jean's Escape time would predict this. I was trying to think of how it could be possible to speed up the escape time of CO2 and push it out of the atmosphere, but then I read this bit on wiki. Hydrodynamic Escape seems incredible! Some estimates indicate that nearly all carbon on Earth is contained in sedimentary rocks, with the atmospheric portion being approximately 1/250,000 of Earth's CO2 reservoir.[citation needed] If both of the reservoirs were released to the atmosphere, Earth's atmosphere would be even denser than Venus's atmosphere. Therefore, the dominant “loss” mechanism of Earth's atmosphere is not escape to space, but sequestration.
Good point, but I'd imagine that the low mixing ratio of H2 makes it difficult to actually encounter O2 or anything else that it can readily bond to. Trees, finding a way to convert it into other solids, and other novel ideas are the best bet. Whatever keeps it on the surface/in the ground. This won't solve our climate issues but the idea of vapor deposition of atmospheric carbon to create nanofibers is immensely cool.The thing about hydrogen is that it is very reactive and wants to bond with something, anything. And if there is a single oxygen atom and a single hydrogen atom, they will combine into a hydroxyl (OH-) and then bond to either nitrogen or carbon.
Actually, you can consider the low mixing ratio of H2 to be a result of reconciling several ideas we've been discussing here. H2 overwhelmingly escapes due to its low mass, and any H's that have formed OH- and bonded to N's or C's are heavier than the dominant species, N2, so those molecules essentially precipitate/sequester, via various mechanisms. And of course there's OH- bonding to H+ to yield water, and due to H2O still having a significant molecular dipole moment, it stays rather low in the atmosphere. The mixing ratio of H2 would be even lower if we weren't constantly receiving a more or less steady supply H+ ions from the solar wind. francopoli, am I thinking about this correctly? We are approaching a rather technical discussion :). So to sum it up, carbon is the devil, trees can kinda kill the devil, and mankind is winning the war against trees. Right now I'm imagining what type of market and climate conditions would have companies launching carbon sinks into space for a net profit via carbon credits. Wooooo, what a wild Friday night!!