cossatot a month ago

I wonder how much the Van Allen radiation belts are a contributor to the Fermi paradox, i.e. how much they contributed to providing a suitable place for life to originate and flourish, and how rare they are.

The belts themselves are an effect of Earth's magnetic field, which I believe is particularly strong because of flow within the Earth's liquid iron-nickel outer core. (I had long believed that the spinning of the inner core was the primary contributor but given a surface-level skim of the literature that doesn't seem to be the case; convection seems to be more of a driver.)

I think perhaps many otherwise similar planets don't have a liquid iron core, so they may not have the strong radiation belts that shield life from the solar wind. Of course I am not sure what fraction of otherwise-similar planets have liquid iron cores, but Mars for example does not seem to. It is probably a function of the size of a planet (governing the pressure distribution in the interior), the ratio of iron to other elements, the temperature field (a function of the amount of radiogenic elements in the planet and its age), and perhaps other factors. Other planets may not be hot enough to have a liquid iron core at the right pressures, or be too massive (too much pressure) at the right temperatures, etc.

  • groos a month ago

    The composition of a planet's atmosphere has to do with the RMS velocity of gas molecules at a given planetary temperature. When this velocity exceeds the escape velocity of the planet, that gas is lost to space.

    But there is one more factor. In the absence of a magnetic field, gas molecules can dissociate from being hit with the particles from the solar wind. E.g., water can dissociate into oxygen and hydrogen, and hydrogen having a relatively high RMS velocity readily leaks out to space. The remaining oxygen is too reactive to remain and then forms carbonates in rocks and carbon dioxide in the atmosphere. This is, from what I read, the explanation for the atmospheres of both Mars and Venus, which have only a small to non-existent magnetic field.

    So yes, a magnetic field seems to be essential to holding a life-friendly atmosphere.

  • s1artibartfast a month ago

    I think that solar radiation isn't a direct danger to life, as it is quickly blocked by the surface of oceans and land. If an atmosphere turns out to be a major factor in the development of life, lack of a field could be a bigger impact. That said, atmospheric stripping like what happened to marks isnt sure bet. Venus has no internal Dynamo, but a massive atmosphere, despite 5X the solar radiation.

  • perihelions a month ago

    I've read that the relative contribution of planetary magnetic fields is overstated relative to atmospheres. The thickness of Earth's is the same mass as a 10 meter-high column of liquid water; not much radiation gets through that much shielding, magnetic field or no. (I think it's solely muons?)

  • dekhn a month ago

    I'm pretty sure that the belts are a requirement for some types of life to originate and survive. Along with Jupiter helping protect us, our location in the galaxy, etc.

    • doctoboggan a month ago

      If abiogenesis occurred in the thermal vents deep under the ocean I believe that could have happened without the radiation protection as the water would be more than adequate.

      • dekhn a month ago

        Sure, but small amounts of radiation are beneficial. And those early organisms would eventually ahve to move to the shallows and land and deal with all the masked radiation at some point. It's all speculation, we really have no idea whether it was vents-first or not.

        • tiniestcabbage a month ago

          > And those early organisms would eventually [have] to move to the shallows and land and deal with all the masked radiation at some point.

          Do they, though? Why is land the requirement? What's keeping life from, say, evolving to live deep underground? Or in the deep ocean? Both those places are heavily shielded from radiation, and organisms there wouldn't be affected much at all by not having a magnetosphere. Extremophiles on Earth get by just fine hanging around thermal vents, for instance. (Edit: this was mentioned above and I didn't see it - sorry for repeating.)

          I think part of the problem with the Fermi paradox is that our base assumptions about what life needs are possibly a bit off. Maybe the fact that we have what we have is, well, quirky, and the fact that we evolved as living creatures that crawl around on the outside of our planet and need really fussy little temperatures to survive is just plain weird in comparison to the rest of the universe.

          "Life as we know it" is a lot tougher criterion to meet than "life," I suspect.

          • SoftTalker a month ago

            Life may be abundant. Intelligent life with technological civilizations is probably not. It took 4 billion years on earth. That’s 1/3 the age of the universe.

          • dekhn a month ago

            These are all fair questions, and to go further, life may not even have required light at all- there are chemoautotrophs living deep in the rock that never see light.

            I was going to say "obviously, nothing I said above would apply to life as we don't know it, like on the surface of a neutron star".

  • jordanb a month ago

    Earth is the only rocky planet in the solar system with a magnetic core so that'd be 1/4 at least.

roymurdock a month ago

Interesting, so the 2 new belts (fields) are closer than the 2 stable existing belts (Van Allen Belts) that shield us from radiation.

These fields could affect the launch and operation of satellites. Or maybe they will help shield us further? Or affect our atmosphere in some way? To be studied...

ck2 a month ago

vague memories of Starfish Prime

https://en.wikipedia.org/wiki/Starfish_Prime#After_effects

where they accidentally created a new radiation belt in orbit

and destroyed some of the first commercial satellites

  • le-mark a month ago

    Is it true this is also why nuclear pulse propulsion from Earth surface to orbit is impractical?

    • floydnoel a month ago

      no that would be because you can't reach escape velocity

MrGuts a month ago

"Mysterious Radiation Belts Detected Around Earth After Epic Solar Storm"

I'm sure there was a 1950's sci-fi movie based on this premise.

gregwebs a month ago

A reason given for the dramatic increase in solar storm effects on Earth is that the Earth’s magnetic field is weakening. This is due to the current geomagnetic excursion where the location of the geomagnetic poles is changing.

sieste a month ago

I wonder if the spatial distribution of intensity from radiation belts correlate with "cancer clusters". Even if the effect is tiny you might be able to see it in the population.

dang a month ago

[stub for offtopicness]

  • porcoda a month ago

    I really wish sites would stop with the clickbait style headlines. “Mysterious” is unnecessary here since there isn’t much mystery about this. If anything, this kind of wording gives non-experts and non-scientists the wrong message since mysterious often gets read as “scary” or “unexplainable”, which is often misleading.

    • dang a month ago

      Ok, we've made the title less mysterious (and less epic) above.

    • anigbrowl a month ago

      It's previously unseen and we don't fully understand it, that's good enough for me to call it mysterious. I don't really care what connotations others may or may not attach to the word.

    • layer8 a month ago

      “Epic” stood out more to me than “mysterious” in terms of low-brow clickbaitiness.

    • pithanyChan a month ago

      exciting is the word you are looking for, porcoda. non-expert lurkas find the unexplainable as stimulating as skimming over the mysteries of SDF or speed reading through LSD & Samagon themed anti-communist feel good novels â læ Hesse (Vilnius Romé or something).

      Radiation? Radio! Antenas! Thpooky electro-magnetism at a distance? Is that a thing? Is there a chance?

      ( Sureley, you understand I'm only half joking here. )

    • salynchnew a month ago

      While I agree and generally feel the same way, I think it is worth mentioning that the "war for attention" is an existential issue for most online publications these days. The clickbait headlines are used specifically because it marginally increases readership/views, without which the publication would probably cease to exist.

      • layer8 a month ago

        Then it must surely be more than just a marginal increase.

      • psychoslave a month ago

        Definitely, I would however recommend that next time they would instead use something like "mysterious radiation of the forbidden belt clandestinely detected around censored earth after tremendous epic solar that some governments might try to hide, the 42th reason will surprise you" without what I am afraid that the entire staff is going to go through a major life crisis before they even had any child possibly contributing to a quick extinction of human species, warning, danger, how dare you not read the article yet?

    • s1artibartfast a month ago

      [flagged]

      • dang a month ago

        You broke the site guidelines badly in this thread, more than once. Not cool.

        We ban accounts that do this and we've warned you more than once before. I don't want to ban you, so if you'd please fix this, that would be good.

        https://news.ycombinator.com/newsguidelines.html

        • s1artibartfast a month ago

          I agree my point would have been better served attacking the message, not the messenger.

          I think there are few things less curious and less scientific than objecting to seeing mystery in the physical world.

          I dont think it is hyperbolic or fearmongering to use mystery in conjunction is science.

          For example, when describing a never before observed proton radiation belt, with unexplained duration. Or when most of that radiation belt is still uncharacterized and out of the detection range of instruments. Or when this never before seen proton belt is expected to last very long time, perhaps over a year, form a single transient storm [1].

          https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/202...

          I dont think it is appropriate to editorialize the titles of submission links to strip out authorial intent to highlight and share this mystery.

          That said, The above text would have made a more robust critique that is more in-line with the sight guidelines. I just got fired up reading how much people hate scientists for their passion[2] and their application causal reductionism

          https://news.ycombinator.com/item?id=42976134

      • foxglacier a month ago

        It's a super common behavior on social media. Worrying about what the stupid people might think if they see something. It's always some hypothetical group of lower-thinking people that they worry about, even when there's no sign of them existing. I'd say it's sometimes just pretending to be concerned about harm to others to make their position seem more important and right, and sometimes a fear that other people might believe different (thus obviously wrong and even immoral) things to themselves.

    • 52-6F-62 a month ago

      This is a projection of your inner state onto the word and not the word itself. It truly is a mystery. Like most things.

      • allemagne a month ago

        In the context of a news headline the decision to use the word "mysterious" and "detected" obviously implies a different kind of significance than the inherent mystery in all things. Other comments in this thread already bring up science fiction movies and other radiation-related disasters, I don't think OP is that much out on a limb here.

        • s1artibartfast a month ago

          I think that is projection too. Mysterious can mean exciting, unknown, and curious.

          Why does this bother people? it isn't like the article is inducing mass hysteria.

          • card_zero a month ago

            The article itself vacillates.

            > we've seen this phenomenon before

            > I said, 'Wow, this is something really new'

            > it's unsurprising

            > Even so [...] what they saw surprised them.

            I mean that's nerdy scientists for you, they get so into their thing it's kind of disgusting. I watched a documentary about volcanos once, it had a husband and wife team, they were just enthusing endlessly about their particular volcano that they were studying and it really turned me off. This was about 20 years ago and as a result I still hate vulcanologists, they totally overdid the sales pitch.

            • s1artibartfast a month ago

              I can only assume you are sarcastic about your hate for scientists that love their work.

      • baxtr a month ago

        I wonder almost daily why anything at all exists. It’s an absolute mystery.

        Why isn’t there just void? So here we are on a tiny planet alone. Alone?

        How did we get here? Are we living in a simulation? Maybe we are in Sim Planet game for another entity?

        All of our existence is mystery.

        • netsharc a month ago
          • baxtr a month ago

            Nah, what’s the point of living then anyway? It’s sounds smart but if you look past it you realize it’s just nihilistic.

            • netsharc a month ago

              If you've got a better "*istic", you're free to convince people that's the way...

              • baxtr a month ago

                I don’t. But I invite you to answer my question!

                • netsharc a month ago

                  Meh, great way of making your problem mine.

                  The point is: just to enjoy the fleeting moment of consciousnees? Oh no, I bet you won't be satisfied with this answer and you want more...

                  • baxtr a month ago

                    Actually I think that’s a good answer! I think it’s worth enjoying every moment that we have. And to be focused.

                    Is it my preferred answer? I guess not :)

        • card_zero a month ago

          Being in a simulation only makes the question more complicated, in a "turtles all the way down" style.

      • mock-possum a month ago

        Is it projection, or just a matter of media literacy?

        We know what the radiation belt is, where it is, and where it came from; so why exactly is this a ‘mystery?’

        • 52-6F-62 a month ago

          They say as much. They’ve never seen it before, and it’s measurable. So this means they can study it for the first time. It literally is a mystery lol.

        • s1artibartfast a month ago

          Great, so we should cancel all scientific research because everything is known. The universe exists: QED. no need to explain or understand phenomenon beyond them having a name

          • 52-6F-62 a month ago

            These people are completely unreasonable.

            It’s actually getting harder and harder to even play devil’s advocate for the sake of ensuring we aren’t collectively ensnaring ourselves in destructive biases.

            They think everything worth knowing is known. Art is “solved” as a problem. Science is absolute (even though science and math all reduce to nil by their own definition).

            We’re seeing the steep rise of a new form of dogmatism unlike anything before save for theocracies.

            This thread is all bickering about words and context that weren’t even present! It’s painful.

jjulius a month ago

[flagged]

  • Cthulhu_ a month ago

    It's the problem with 3rd / 4th level articles, that is, 1st level is a scientific paper, 2nd is a press release, 3rd / 4th are the media and popular science outlets. It's how you get from some numbers / statistics representing a slight dimming in a distant star to artist's renditions of verdant blue/green exoplanets.

    But the scientific papers aren't interesting on their own, they need explanation first so people know what it entails, then entertainment so people get interested. Or in this case, provoke outrage so that they get people upset and reacting to it.

    • s1artibartfast a month ago

      Papers are interesting, but usually much less accessible. There is nothing inherently wrong with the idea of scientific reporting. However, many publishers have historically gone overboard with sensationalism, which spurred a lot of knee-jerk reactionary sentiment.

      In this case, I don't think it is really warranted. I thought the article was about as straight forward as one could expect for an introduction of this length, and avoided sensationalism. The only hazard mentioned is that to satellites, which is mentioned as a concern on area of research in the original article (which they actually linked for once!).

  • codr7 a month ago

    Pretending to know everything, and especially being right, is a pretty big thing around here.

  • IAmGraydon a month ago

    I assure you that scientists did not use the word “mysterious”. The site did to get more people to click. The people of HN really dislike it when a site treats them like gullible idiots.

    • jjulius a month ago

      Yeah, I know they didn't, which is why I didn't use the word in my own quotes. My point was that seizing on "mysterious" is stupid. Scientists found something new to them and were fascinated. "Mysterious" might not be the most perfectly cromulent word for this situation, but it's close enough with regards to conveying their awe.

      Discussing what was discovered is a far more interesting conversation that yet another rant about how some word in a headline feels like clickbait to someone. For a site that prides itself on fostering quality discussion, it surprises me that this sort of perspective is downvoted.