Wisdom of Sci-Fi: The Litany Against Fear

Hello, friends!

I may lose some geeky street cred by admitting this, but I don’t have the Litany Against Fear from Dune memorized.  I can get through the first two or three lines, but after that I get the words all muddled up, and then I usually just trail off into silence.  That’s a shame, because I’ve heard that the Litany really does help people cope with extreme fear and anxiety.

Before I talk about the Litany Against Fear and why it apparently does work (at least for some people), I want to acknowledge the fact that fear is not always a bad thing.  There’s a scene from Star Trek: Voyager that’s stuck with me over the years, a scene where Captain Janeway confronts an alien being who is supposed to be the living embodiment of fear.  When speaking to this being, Janeway has this to say:

I’ve known fear.  It’s a very healthy thing, most of the time.  You warn us of danger, remind us of our limits, protect us from carelessness.  I’ve learned to trust fear.

People who are or who claim to be totally fearless are, in my mind, kind of stupid.  There really are things in this world to be afraid of.  But sometimes fear gets out of hand, either inhibiting us in our daily lives or causing us to react to perceived threats in ways that are harmful, both to ourselves and to others.

This brings us to something called the “amygdala hijack.”  The term was coined in 1995 by American psychologist Daniel Goleman, and it refers to the way the amygdala (a part of the brain associated with, among other things, fear) can sometimes override our more logical brain functions.  Once the amygdala perceives a threat (real or otherwise), it can hijack control over the rest of our brains and throw us into an immediate fight/flight/freeze response.

Earlier this year, I spent some time talking to a therapist.  Some family stuff was going on, and I needed help processing it all.  My therapist and I ended up talking a lot about the amygdala hijack, and I learned that it is possible to stop an amygdala hijacking in progress or prevent it from happening in the first place.  It doesn’t take much.  On one occasion, I tried simply saying out loud, “Hey amygdala, cut it out!”  That actually worked.

There are also mindfulness exercises you can try.  Reciting a prayer or mantra may also help.  Or you could try using the Litany Against Fear.  A few people have told me that the Litany really does work, and given what I’ve learned about the amygdala hijack, I can totally see why.  First off, the Litany calls direct attention to what your amygdala is doing: mind-killing.  Taking the time to recite the rest of the Litany then gives your brain the time it needs to recover.  Several sources I’ve looked at mention that it takes about six seconds for the rational part of your brain to reassert itself after an amygdala hijacking.  The Litany is just a bit longer than six seconds.

Maybe it’s finally time I memorized the Litany Against Fear in full.

WANT TO LEARN MORE?

Check out some of these articles:

“Why Dune’s Litany Against Fear is Good Psychological Advice” from Forbes.com.
“Amygdala Hijack: When Emotion Takes Over” from Healthline.
“Six Seconds to Emotional Intelligence” from Albertus Magnus College Blog.

The Common Europa Hypothesis

Hello, friends!  So Europa month ended a while ago, and I haven’t done much blogging since then.  Sorry about that.  I’ve been distracted by other writing projects.  But I now have some blog time in my schedule again, and I’m ready to blog about some new topics.  Except… I can’t help myself.  There’s one more thing I want to say about Europa.

I have this crazy idea.  I haven’t found much scientific literature to support me on this, but I still think this idea makes scientific sense.  I think that Europa—or rather, Europa-like worlds—may offer a solution to the Fermi Paradox.

For those of you who don’t know, in 1950, Italian physicist Enrico Fermi famously asked “Where is everybody?” in reference to extraterrestrial life.  Fermi argued that alien life should be all around us.  Almost everywhere we look in the cosmos, we should find alien beings waving back at us.  And yet, as of 1950, no real evidence of alien life had been found.  And as of today, in 2021, the situation remains much the same.

One possible answer to Fermi’s question came in the form of the rare Earth hypothesis.  Earth-like planets must be few and far between.  To be clear, when I say Earth-like planets in this context, I mean planets that meet the same Goldilocks parameters as Earth: not too hot, not too cold; not too big, not too small; not too wet, not too dry; et cetera, et cetera.  Planets that are so Goldilocks-perfect must be vanishingly rare in our universe.  Like, you could probably count on one hand how many Earth-like worlds exist in our whole galaxy.  So if life needs an Earth-like environment to survive, that may explain why alien life has been so frustratingly hard to find.

But then there’s Europa, the sixth moon of Jupiter.  Could there be life on Europa or on a Europa-like world?  And when I say a Europa-like world, I mean a world that looks like this:

A Europa-like world is a world with an ocean of liquid water covered up (and protected) by a thick shell of ice.  The mantle and core are hot, much like Earth’s, and hydrothermal vents on the ocean floor offer heat and nutrients to any potential life forms that might develop.

With respect to life on Europa herself, I’m 50/50.  There are good reasons to think Europa is habitable, and there are good reasons to think Europa falls just a little bit short of habitability.  But only a little bit.  Conditions on Europa are either just right for life or almost right.  So even if Europa misses the mark on habitability, another Europa-like world could easily hit it.

And here’s the important thing: while truly Earth-like worlds are rare, Europa-like worlds seem to be quite common.  There are at least two of them here in our own Solar System: Europa (obviously) and Enceladus, one of the moons of Saturn.  And there may be more.  In my research, Ganymede (moon of Jupiter), Dione (moon of Saturn), Titan (moon of Saturn), Ariel (moon of Uranus), and Triton (moon of Neptune) have all come up as places with certain suspiciously Europa-like qualities.  Even Pluto may have some liquid beneath her surface.

I’m choosing to call this idea the common Europa hypothesis, as a nod to the rare Earth hypothesis.  I think Europa-like worlds are common, both here in the Solar System and all across the cosmos.  Even if only 1% of these Europa-like worlds support life, that could still end up being an enormous amount of alien life out there.

Getting back to Enrico Fermi’s original question: “Where is everybody?”  Well, between the rare Earth and common Europa hypotheses, perhaps we have an answer.  Aside from us Earthlings and the lucky few who get to live on Earth-like planets, everybody is swimming around in Europa-like subsurface oceans, beneath thick layers of ice.

WANT TO LEARN MORE?

I suggest reading Exoplanets by Michael Summers and James Trefil.  Among other things, there’s plenty of discussion about all the surprising yet plausible places Europa-like worlds might exist.

#IWSG: Three Things Writing is Like, and One Thing It’s Not

Hello, friends!  Welcome to this month’s meeting of the Insecure Writers Support Group!  Are you a writer?  Do you feel insecure about your writing?  Then this is the support group for you.  Click here to learn more!

Sometimes I get into conversations with people who are not writers.  It can be hard to explain to non-writers what writing is like.  They tend to vastly underestimate (or vastly overestimate) how much of a struggle writing can be.  Also, a few of them seem to assume that heavy drinking must somehow be involved.

Today, I’d like to share a few of the analogies I use to help explain both the joys and hardships of writing to my non-writer friends.

Writing is like exercise:

I am not exactly a health nut, but exercise is still an important part of my routine, and I do, in fact, enjoy it.  That being said, when it’s time to exercise, I’m rarely enthusiastic about getting started.  Getting started is always the hardest part.  However, once I do get going, exercise gets easier, and by the time I’m finished I usually feel proud of myself for the hard work I’ve done.  Writing is the same.

Also, after a hard workout, your body needs some time to rest.  Your mind also needs time to rest after a long, hard day of writing.

Writing is like NASA:

Specifically, writing is like NASA when it comes to setting schedules and deadlines.  Everything seems to take longer than expected.  Just ask the people working on J.W.S.T.  That thing was supposed to launch like fourteen years ago!  Almost every NASA mission is, in one way or another, attempting to do something different and new, something that has never been done before.  Unanticipated problems and setbacks are bound to happen.  Writing is much the same in that respect.

Also, writing is like NASA in the sense that it involves big goals and bigger dreams.  Not everyone sees the value in those goals or dreams, and some people will tell you (whether you asked for their opinion or not) that you should focus on more down-to-earth concerns instead.

Writing is like meditation:

I have to admit that I’m not as religious or spiritual as I once was (for reasons that are not relevant to this blog post).  Even so, when I say that I need to get myself into a meditative state in order to write, most people seem to understand what I mean.  I treat my personal “writing sanctuary” as if it were a sacred place, and my writing process is highly ritualized.  This helps me clear my mind of distractions and let go of material concerns, so that I can give my story my undivided attention while I write.

And if it sometimes feels as if a supernatural power—a muse of some kind, if you will—is helping me do my writing… well, that fits nicely into the meditation analogy as well.

Depending on the circumstances, I may try using one analogy for one person, and a different analogy for somebody else.  Not everyone meditates.  Not everyone cares about NASA.  And as for exercise, the statement “I enjoy exercise” can be more perplexing to some people than “I’m a writer.”  But usually, at least one of these analogies will communicate to a non-writer what writing is like for me.

Lastly, I want to share one analogy for writing that absolutely does not work.

Writing is like eating cookies:

It’s not.  No, it really isn’t.  Sometimes writing is easy, sometimes it’s hard.  That’s not true about eating cookies.  Nobody has ever said, “I feel like I should spend more time eating cookies, but I’m just so gosh-darn tired right now.  Maybe I’ll eat some cookies tomorrow, if I have the energy for it.”

So what analogies would you use to explain writing to non-writers?  And are there any analogies you can think of (like my cookie analogy) that absolutely do not work?

Protect Europa!

Hello, friends!  We’ve reached the end of October, which means we’ve reached the end of Europa month here on Planet Pailly.  We still haven’t determined whether or not Europa is home to alien life, but I hope I’ve persuaded you to take the possibility of life on Europa seriously.

One question that came up a few times this month was whether or not we should send humans to Europa.  The answer, in my opinion, is no.  First off, as we discussed in a previous post, the radiation environment on Europa is crazy dangerous.  We humans would also struggle with the extreme cold and the very low surface gravity.  I’m not saying a colony on Europa is impossible, but there are far safer and easier places we could choose to go.  The neighboring moons of Ganymede and Callisto, for example, would serve as safer and more comfortable bases of operation for humans.

But there’s another reason why colonizing Europa seems like a bad idea to me.  It’s not a science reason.  It’s a legal issue.  There’s an international agreement in place (Article IX of the 1967 Outer Space Treaty) which forbids space agencies like NASA, the E.S.A., or Roscosmos from contaminating other worlds with our Earth germs.  The same agreement also forbids contaminating Earth with germs from other planets.

Some missions are considered riskier than others, contamination-wise.  For example, Article IX doesn’t really apply to NASA’s Parker Solar Probe.  There’s no chance Earth germs will be able to contaminate the Sun (and since the probe will not be returning to Earth, there’s no chance any lifeforms from the Sun could contaminate Earth).  There’s actually a whole risk categorization system in place, with five different categories of risk, and a bunch of sub-categories, too.  Click here if you want to know more details about that.

The important thing for our purposes is that any mission to Europa will involve a very high risk of contamination.  We may not know yet if alien life exists on Europa, but the possibility should be taken seriously.  The people who wrote the Outer Space Treaty made it clear that they’d learned the lessons of history and did not want to repeat the mistakes of the past.  We would not want Earth germs to endanger an alien ecosystem on Europa (nor would we want Europa germs endangering Earth-life).

So for the foreseeable future, I think Europa will be off limits to humans.  Europa might even be declared an interplanetary wilderness preserve, or something like that, and if there’s scientific research to be done on Europa, it can be done remotely from bases on Ganymede or Callisto.

There are easier places in the Solar System for us humans to colonize.  There’s no need for humans to go there.  So unless and until someone shows the contamination risk on Europa is zero, let’s leave Europa alone.

WANT TO LEARN MORE?

As part of my research for this post, I read the two papers listed below.  If you’re interested in how Earth laws work (or don’t work) in outer space, these papers are worth a look.  Also, if you’re interested in writing Sci-Fi, these papers may get the wheels of your Sci-Fi writer brain turning.

Would Europa Life Have Bioluminescence?

Hello, friends!

All month long, we’ve been talking about Europa, the sixth moon of Jupiter.  Scientists are 99% sure that there’s an ocean of liquid water beneath Europa’s icy crust, and speculation runs rampant about possible alien life swimming around in that subsurface ocean.

I’m currently reading a book called The Zoologist’s Guide to the Galaxy, by Arik Kershenbaum.  The book takes the fairly uncontroversial stance that the same evolutionary processes that shaped life on Earth would shape life on other worlds (uncontroversial among the scientific community, at least).  Specific details about biochemistry or genetics might be wildly different, but general principles like natural selection are likely universal.

Other science writers follow the same premise when imagining what we might find beneath the surface of Europa.  The environment is presumed to be very similar to the deepest, darkest reaches of Earth’s oceans.  Therefore, the same evolutionary pressures should apply, and Europa-life should have much in common with the deep ocean creatures we find here on Earth.

For example, Europa-life would probably cluster around hydrothermal vents, or similar geological hot spots, at the bottom of the ocean.  It’s nice and warm there, and there are plenty of tasty nutrients billowing up from the rocky mantle.

Another example: abyssal gigantism, which is the tendency for organisms in the deep ocean to grow to enormous sizes (compared to their shallow water cousins).  Scientists aren’t 100% sure why abyssal gigantism happens, but it may have something to do with metabolic efficiency.  If life in Earth’s deep oceans needs to be gigantic for the sake of metabolic efficiency, then Europa-life would probably be gigantic too.

A lot of science writers also predict that bioluminescence will be common on Europa.  It’s fairly common here on Earth, especially in the deepest, darkest regions of Earth’s oceans.  And as you can see in this totally legit photo from the Mariana Trench, bioluminescence is really pretty.

But while predictions about abyssal giants and hydrothermal vents make a certain logical sense to me, I’m not convinced bioluminescence makes sense on Europa.  As I understand it, life on Earth developed eyes first, and bioluminescence came later.

Having some sort of light-detecting organ makes sense on a world where there’s plentiful sunlight.  There’s an obvious evolutionary advantage to having eyes here on Earth.  And then, if some Earth-creatures decided to swim down to the bottom of the ocean, it makes sense for them to develop bioluminescence in order to help them see each other and the environment around them (or to help them lure in food).

But the ocean on Europa lies beneath a thick shell of ice.  There’s no sunlight there.  There has never been sunlight there.  So what is the evolutionary advantage of having eyes?  And if there’s no evolutionary advantage to having eyes, what would be the evolutionary advantage of bioluminescence?

Whenever Europa-life is depicted in science fiction, it’s almost always lit up in bold, bioluminescent colors.  A lot of science communicators seem to envision Europa-life that way too.  And why wouldn’t they?  To see all those strange alien creatures waving their glow-tentacles around—that would be an awe-inspiring sight!  But as awesome as it would be to see Europa-life in all its bioluminescent glory, I cannot think of a good reason why Europa-life would evolve that ability. Can you?

WANT TO LEARN MORE?

I haven’t finished reading The Zoologist’s Guide to the Galaxy yet, but what I’ve read so far is good, thought-provoking stuff.  If you’re interested in what alien life might really be like, scientifically speaking, then I’d say this book is worth a look.

The Colors of Europa: What’s That Red Stuff on Europa’s Surface?

Hello, friends!

Europa (one of the moons of Jupiter) is said to have the smoothest, youngest-looking surface of any planet or moon in the whole Solar System.  But Europa’s surface, as astonishingly smooth as it is, still isn’t perfectly smooth.  As you can see in the totally legit Hubble image below, there are dark-colored cracks and rough patches, and there are also blob-shaped discolorations that kind of look like the birthmark on Mikhail Gorbachev’s head.

I don’t want to get political on this blog, but this Gorbachev quote seems appropriate to me.

Fifteen to twenty years ago, when I started teaching myself about space, the things I read about Europa made it sound like scientists had no idea what caused the discolorations on Europa.  The blue-grey regions were frozen water, obviously; but the reddish-brown stuff… that could be anything!  Tholin?  Sulfur?  Amino acids?  Alien poo?  Anything.  Those reddish-brown areas may as well have been marked “here be dragons,” chemically speaking.

Today, though, it seems like scientists have seriously narrowed down the range of possibilities.

Sulfuric Acid: Io, one of Jupiter’s other moons, happens to be the most volcanically active object in the Solar System.  Io is so volcanically active that sulfur from Io shoots up into space and spreads to the neighboring Jovian moons.  On Europa, Io’s sulfur can react with Europa’s frozen water to create sulfuric acid (H2SO4).  This could explain some of the discoloration we see on Europa.

Epsom Salts: The discoloration could also be explained by a different sulfur compound: magnesium sulfate (MgSO4).  Also known as Epsom salts, magnesium sulfate is found in Earth’s oceans, and it’s reasonable to guess that it might be found in Europa’s subsurface ocean as well.  If so, magnesium sulfate could be spilling onto Europa’s surface through cracks and fissures in the surface ice.

Table Salt: In a previous post, I told you about the intense radiation environment on Europa’s surface.  Recent laboratory experiments have shown that sodium chloride (NaCl) can change color when exposed to that much radiation.  Just like magnesium sulfate, sodium chloride could be welling up to the surface through cracks and fissures in the ice.  And after a bit of radiation exposure, sodium chloride could cause the kind of discoloration we see on Europa.

So which of these three chemicals causes the discoloration on Europa?  Or is it some combination of all three?  From what I’ve read, I don’t think the scientific community has reached a consensus on that.  Much of the discoloration we see is in the vicinity of cracks, fissures, or other breaches in Europa’s surface.  That seems to favor sodium chloride and/or magnesium sulfate as the explanation.  However, one hemisphere of Europa is more exposed to the sulfur cloud coming from Io than the other.  And guess what!  The hemisphere that’s more exposed to Io is also more discolored!  That evidence seems to favor sulfuric acid as the explanation.

But again, I don’t think there’s a consensus about this yet.  This is still a topic of some debate among the scientific community.  However, the fact that we’ve gone from “it could be anything, here be dragons (chemically speaking)” to “it’s one or more of these three chemical substances” seems like real progress to me.

WANT TO LEARN MORE?

I relied on these three research papers for this post.  Together, I think they show the evolving conversation about Europa’s discolored regions over the last few years.

I wish I could recommend some easier and more accessible articles on this topic, but the ones I read all made claims like “scientists prove Europa’s covered in Epsom salts!”  Those sorts of articles do not reflect what the actual research papers are saying.

Sciency Words: Europa Edition

Hello, friends, and welcome back to Sciency Words!  That’s right, Sciency Words is back!  I’m going to handle this series a little differently than I did before.  I could explain what those differences are, but I think it’s better if we just dive right in so you can see for yourselves.

Since this is officially Europa Month here on Planet Pailly, we’re going to turn our attention to Europa, the sixth moon of Jupiter.  When exploring alien worlds, scientists sometimes discover geological features that are not found here on Earth.  When that happens, scientists need to invent new words to describe what they’re seeing.  Here are a few of the terms used to describe geological surface features seen on Europa.

Chaos Terrain: For the most part, Europa’s surface is made of very smooth, very fresh-looking ice.  But in some regions, we find these big, broken chunks of ice in a state of chaotic disarray.  Imagine a bunch of icebergs breaking loose from a glacier.  Now imagine that, before the icebergs drift too far, the water around them freezes, locking those icebergs in place.  That’s basically what chaos terrain looks like.  Oh, and chaos terrain tends to be discolored with some sort of reddish-brown substance.  Click here to see some chaos terrain on Europa.

Linea (plural, lineae): From the Latin word for line, linea means… line.  Reddish-brown lineae crisscross the surface of Europa.  They appear to be cracks in Europa’s icy surface, cracks which have been filled in by a mixture of freshly frozen ice and more of that reddish-brown substance.  Click here to see a color enhanced view of Europa’s lineae.

Lenticula (plural, lenticulae): From the Latin word for freckles, lenticulae are small, reddish-brown spots scattered all over the surface of Europa.  They tend to be round, but they don’t appear to be impact craters, which means they’re probably caused by something happening beneath Europa’s surface.  Click here to see a cluster of lenticulae on Europa’s surface.

Macula (plural, maculae): From the Latin word for spot, maculae are spots of discoloration on the surface of a planet or moon.  Europa’s maculae are irregularly shaped blotches of reddish-brown color.  At least one macula (known as Thera Macula) has been identified as a possible region of active chaos terrain formation.  Click here for a closer look at Thera Macula.

It’s extremely cold in the outer Solar System, so cold that water behaves almost like a kind of rock.  When thinking about icy worlds like Europa, it can be helpful to conceptualize water in that way.  Water is a kind of rock.  With that in mind, Europa’s icy surface is much like the rocky crust we have here on Earth, and Europa’s subsurface ocean of liquid water is sort of like the layer of molten rock that lies beneath Earth’s crust.  And thus the surface features we see on Europa might be caused by processes similar to the tectonic and volcanic activity we experience here on Earth.

There are, of course, other geological terms associated with Europa, but for this post I wanted to focus on just these four.  Europa’s chaos terrain, lineae, lenticulae, and maculae all have something important in common: that reddish-brown discoloration.  Next time on Planet Pailly, we’ll try to figure out what, exactly, that reddish-brown stuff on Europa is.

Radiation on Europa: How Quickly Would It Kill You?

Hello, friends!  If you happen to have any radiation protection clothing lying around—like those lead aprons they give you for X-rays at the dentist—I recommend putting it on now before you read any further.  In today’s post, we’ll be exploring the radiation environment of Europa.

Europa is often listed as one of the top four places in the Solar System where we might find alien life.  That makes exploring Europa a top priority for NASA and other space agencies.  Unfortunately, Europa is one of the moons of Jupiter, with an orbit that puts Europa deep inside Jupiter’s radiation belts.

Radiation is going to be a problem wherever you go in space, but the radiation belts around Jupiter are extra scary. If you were to spend a few days on the surface of the Moon or Mars without any sort of radiation protection gear, you’d end up with a significantly higher risk of developing cancer at some point later in life.  If you spent a similar amount of time on the surface of Europa without radiation protection, you wouldn’t live long enough to worry about cancer.  Radiation sickness would kill you in a matter of days—maybe a matter of weeks, if you’re “lucky.”

– NASA’s Juno space probe flying through radiation near Jupiter.

Even robotic spacecraft have a tough time dealing with Jupiter’s radiation belts.  The Juno mission, currently orbiting Jupiter, has all its mission critical electronics sealed up inside what NASA calls a radiation vault.  It’s basically a big, heavy box with thick walls made of titanium.  The radiation vault cannot block all of the radiation, but it blocks enough of it that Juno should survive long enough to finish its mission.

NASA’s upcoming Europa Clipper mission, which will take an even closer look at Europa, will be equipped with a similar radiation vault.

Before we end today’s post, some of you may be wondering what all this radiation means for potential alien organisms living on Europa.  Well, it probably wouldn’t affect them much, if at all.  The aliens (if they exist) would be swimming around in Europa’s subsurface ocean, beneath several kilometers worth of water ice.  And large quantities of water happen to be one of the very best radiation shields nature can provide.

WANT TO LEARN MORE?

  • “Colonization of Europa” from Wikipedia.  Yeah, it’s a Wikipedia article, but if you’re interested in what it would take to put human beings on the surface of Europa, this article is a pretty good place to start.
  • “Juno Armored Up to Go to Jupiter” from nasa.gov.  This is a press release from 2010, when the Juno spacecraft was still under construction.  It describes, in plain English, what Juno’s radiation vault is and why Juno needs it so badly.
  • “Spent Fuel Pool” from What If?  For those of you who didn’t know about water’s incredible radiation blocking powers, this is an amusing look at water’s incredible radiation blocking powers.

#IWSG: Scriptophobia and Graphophobia

Hello, friends!  Welcome to this month’s meeting of the Insecure Writer’s Support Group.  If you’re an insecure writer in need of some support, then guess what!  This is the group for you!  Click here to learn more.

I recently learned that there is, in fact, a scientific term for the fear of writing.  Actually, there are two.  Scriptophobia is the fear of writing in public.  Graphophobia is the fear of writing in general.

Honestly, I’m not surprised that these terms exist.  I’ve never understood how some writers can do their writing in the middle of a coffee shop.  I’d feel so self-conscious.  Does that make me scriptophobic?

And graphophobia?  For me, that’s something that comes and goes.  It’s a feeling that I’ve traditionally labeled as writer’s block, but graphophobia (now that I know about that word) seems like a more apt term.  It really is fear that stops me from writing.  Fear that I’ll disappoint myself.  Fear that I’ll disappoint my readers.  Fear that I’m wasting time writing something that no one will ever want to read.

I said that fear stops me from writing, but it would be more accurate to say fear hinders me from starting to write.  Just starting is always the hardest part.  But once I’ve done a few sentences, or a few paragraphs, or maybe a few pages, the words come quickly and easily, and I’m left wondering what I was afraid of in the first place.

Learning new vocabulary is the best kind of learning, in my opinion.  Knowing the right terms and the right names for things makes those things so much easier to conceptualize within one’s own brain, and it also makes it easier to communicate one’s thoughts, feelings, and questions about those things with other people.  That’s why I’m so glad to have discovered the words scriptophobia and graphophobia.  These are going to be very useful terms for me.  I hope you’ll find them useful, too.

How Do They Know That: Europa’s Subsurface Ocean

Hello, friends!

This month is Europa month here on Planet Pailly!  For those of you who haven’t met Europa before, she’s one of the moons of Jupiter, and she’s generally counted among the top four places in the Solar System where we might find alien life.  This is in large part because Europa has a vast, global ocean of liquid water hidden beneath her surface.  By most estimates, Europa has twice as much liquid water as Earth!

But one might reasonably ask how we know, for certain, that Europa’s ocean of liquid water exists.  I mean, no space probe has ever cracked through Europa’s surface to check.  Not yet, anyway.  Which brings us to another episode of “How Do That Know That?”

HOW DO THEY KNOW THAT?
EUROPA’S SUBSURFACE OCEAN

There are three main lines of evidence pointing to the existence of Europa’s ocean: spectroscopic evidence, gravitational evidence, and magnetic evidence.

  • Spectroscopy: Every chemical substance in the universe interacts with light in its own unique way.  Very specific wavelengths of light will be absorbed and/or emitted, depending on what chemical substance you’re looking at.  So by measuring the wavelengths of light reflecting off Europa, scientists could determine what Europa’s surface is made of.  I won’t leave you in suspense.  The answer is water.  Frozen water.
  • Gravity: In the 1990’s, NASA’s Galileo spacecraft conducted several close flybys of Europa.  Each time, Europa’s gravity nudged Galileo ever so slightly off course.  By measuring exactly how much gravitational nudging Galileo experienced, scientists could calculate what Europa’s internal structure must be like.  Turned out there was a thick layer of low density material near the surface.  Water, in either a frozen or liquid phase, has a pretty low density.
  • Magnetism: Jupiter has an absurdly powerful magnetic field.  As Europa orbits Jupiter, a mysterious something inside Europa responds to Jupiter’s magnetism, creating what’s called an “induced magnetic field” around Europa.  Once again using data from the Galileo spacecraft, scientists could measure the shifting and changing intensity and orientation of Europa’s magnetic field as she orbited Jupiter.  As it so happens, a large volume of saltwater would react to Jupiter’s magnetic field in much the same way as the mysterious something inside Europa.

Taken individually, each line of evidence would have to be considered inconclusive.  Suggestive, perhaps, but ultimately inconclusive.  Sure, spectroscopy tells us there’s frozen water on Europa’s surface, but that layer of frozen water might only be skin deep.  Gravity data tells us there’s a very deep layer of low density material, but gravity data, by itself, cannot tells us what that low density material is.  And if you didn’t know anything else about Europa’s internal structure or chemical composition, then her induced magnetic field could be explained in many different ways.  Taken together, though, these three lines of evidence leave little room for doubt: there’s an ocean of liquid water (specifically saltwater) beneath the surface of Europa.

Science is, in my mind, a little like trying to solve a crossword puzzle.  Not all the answers are obvious at first, but with each word in the puzzle you find, the intersecting words become a little easier to figure out.  Maybe you thought the answer to 17 across (What’s beneath the surface of Europa?) could be three or four different things.  But then you found out the middle letter is a T, and the last letter is an R, and now you can narrow down the possibilities to one and only one solution.

By following multiple lines of evidence, scientists can now say, with a very high degree of certainty, that there’s an ocean of liquid water beneath the surface Europa.  Exactly how thick is the ice above that ocean?  And what minerals are present in the ocean?  How much hydrothermal activity occurs at the bottom of that ocean?  Those are some of the next questions that need answers.

WANT TO LEARN MORE?

There’s a lot of information out there about Europa.  A little too much, actually.  It’s hard to sort through it all.  So if you want to learn more about Europa, I highly recommend Alien Oceans: The Search for Life in the Depths of Space by Kevin Peter Hand.  It’s got all the best Europa facts you could ever want, all together in a single book.  And Hand devotes a full chapter to each of those lines of evidence that I listed above.