Abyssal Gigantism on Europa?

Hello, friends!

So the first time I heard about the subsurface ocean on Europa (one of Jupiter’s moons), my imagination ran wild.  Or should I say it swam wild?  I imagined all sorts of wonderful and terrifying sea creatures: krakens with lots of horrible tentacles and teeth; crab-like creatures scuttling around on the ocean floor; and perhaps even extraterrestrial merfolk with a rich and complex civilization of their own.

As I’ve learned more about space and science, though, I’ve scaled back my expectations for what we might find on Europa.  Or on Enceladus, or Dione, or Titan, or Ariel, or Pluto… there’s a growing list of planetoids in the outer Solar System where subsurface oceans of liquid water are suspected and/or confirmed to exist.

Any or all of those worlds might support alien life.  But not giant sea monsters.  When astrobiologists talk about alien life, they’re usually talking about microorganisms.  For Europa, rather than civilized merfolk and tentacle-flailing leviathans, we should imagine prokaryotic microbes clustered around hydrothermal vents, feeding on sulfur compounds and other mineral nutrients.  If we ever find evidence that these Europan microbes exists, it will come in the form of a weird amino acid residue, or something like that.

That’s the most exciting discovery we can hope for, realistically speaking.  Unless…

On Monday, I introduced you to the term “abyssal gigantism,” also known as “deep-sea gigantism.”  Abyssal gigantism refers to the tendency of deep-sea organisms to grow larger (sometimes much larger) than their shallow-water cousins.  As an example, see the giant squid.  Or if you really want to give yourself nightmares, look up the Japanese spider crab.

The more I read about abyssal gigantism, the more my thoughts turn to Europa (and Enceladus, and all the rest).  The environment beneath Europa’s icy crust shouldn’t be so different from the deepest parts of Earth’s oceans.  So shouldn’t what happens in the deepest parts of Earth’s oceans also happen on Europa?

According to this article from Hakai Magazine, yes.  Yes, it should.  The same evolutionary pressures that cause abyssal gigantism here on Earth should cause a similar kind of gigantism on Europa.  In fact, it would be strange if that didn’t happen.  One marine biologist is quoted in that article saying: “You would have to come up with a rationale why [abyssal gigantism on Europa] couldn’t happen, and I can’t do that.”

Before you or I let our imaginations swim wild, I should note that that article from Hakai Magazine was the one and only source I could find on this specific combination of topics: abyssal gigantism and life on Europa.  So maybe take all of this with a grain of salt (preferably a grain of Europan sea salt).  But… well, I’ll put it to you this way: if someone were to write a story about a NASA submarine being attacked by sea monsters, that story would seem plausible to me.

Sciency Words: FarFarOut

Hello, friends!  Welcome to Sciency Words, a special series here on Planet Pailly where we take a closer look at new and interesting scientific terms so we can expand our scientific vocabularies together!  Today’s Sciency Word is:

FARFAROUT

You know, I recently spent a couple days trapped at home due to a snow storm. Don’t worry, I don’t live in Texas—I wasn’t trapped in that snow storm.  Anyway, after reading a little about Dr. Scott Sheppard, I feel as though I seriously misused those snowed-in days.

Dr. Sheppard is one of the key players in the ongoing search for Planet X, also known as Planet Nine or (as I like to call it) New Pluto.  Together with fellow astronomer Chad Trejillo, Sheppard has discovered more than sixty objects of various sizes out beyond the orbits of Neptune and Pluto.

Among those sixty-plus objects Sheppard and Trejillo discovered is a possible dwarf planet nicknamed “FarOut” (official designation 2018 VG18).  FarOut is—or rather was, very briefly—the most distant natural object known to exist in our Solar System.  Hence the nickname.

But in early 2019, Sheppard was reviewing his data and happened to notice another object even farther out than FarOut.  As Scientific American tells the story, this happened while Sheppard was “snowed in during a blizzard.”  (I spent my recent snowed-in days watching cartoons on my phone.)  The new object Sheppard found in his data has the official designation 2018 AG37, but Sheppard nicknamed it “FarFarOut,” for obvious reasons.

According to this article from Carnegie Science, FarFarOut has a highly eccentric (non-circular) orbit, with an orbital period of approximately one thousand years!  Seriously, a thousand years!!!  A portion of that highly eccentric orbit is actually not that far away at all; at its closest approach to the Sun, FarFarOut’s orbital path actually crosses within the orbit of Neptune.

I do have to take issue with some of the news articles and social media posts I’ve seen about FarFarOut.  Strictly speaking, FarFarOut is not the most distant known object in the Solar System.  We should probably call it the most distant natural object, or the most distant non-articifical object, that we currently know about, because there is one known object that’s even fartherer out than FarFarOut.

Do Planets Have Genders?

Hello, friends!

So a while back, I got some unsolicited feedback from a person I know in real life.  This person had seen one of the illustrations I’d drawn for this blog, and she was incensed—absolutely incensed—that I would depict the planet Saturn as female.  You see, Saturn is a very masculine planet.  That’s a fact, apparently.

A lot of my thinking about planets—including my thinking on the gender identities of planets—was shaped by a book called Venus Revealed, by David Grinspoon.  That book was my first serious introduction to planetary science.  In a section titled “Men are from Venus, Women are from Mars,” Grinspoon has this to say:

At first I tried being completely gender-neutral in my writing, but this was unsatisfying because, to me, Venus is not just a “thing.”  Venus is not, in my mind, inanimate, and so “Cousin It” will never do to describe him… or her.

In that same section, Grinspoon does a little cross-cultural analysis and finds that Venus has been “a real gender bender” across human cultures and human history.  Sometimes she’s male; other times he’s female, depending on which mythological tradition you’re looking at.  And some cultures have apparently assigned different genders to the Morning Star and Evening Star, thus effectively making Venus genderfluid.

So do planet’s have genders?  No, of course not.  But much like David Grinspoon, I can’t see the planets as purely inanimate objects.  Planets have too much personality for that.  And since I think of the planets as having personalities, then, for better or worse, I also think of them as having genders.

For purely arbitrary reasons, I tend to think of Saturn as female.  But if you’d prefer to think of Saturn as male, or as something else entirely, that’s okay.  I’m not going to fight you over it.  I can love Saturn (and all the other planets, too) just the same, no matter what gender identities we pretend they have.

P.S.: While doing research for this post, I ended up reading a lot about how astrology assigns genders to planets (and also to numbers, elements, constellations, etc). I don’t want to dive too far down that particular rabbit hole, but I thought I should at least share this article on the subject. I used to think astrology was just silly. Now I think it’s problematic for reasons that go beyond mere pseudoscience.

Sciency Words: Chromophore

Hello, friends!  Welcome to Sciency Words, a special series here on Planet Pailly where we take a closer look at those weird words scientists use.  Today’s Sciency Word is:

CHROMOPHORE

Recently, just for fun, I was watching an old interview with Carl Sagan (the same interview I cited in Wednesday’s post, by the way).  Around 25 minutes into that interview, Sagan talks a little about Jupiter, and he mentions that Jupiter’s distinctive coloration is caused by something called “chromophores.”

Sagan then goes on to say, flippantly, that we call it a chromophore because “we don’t know what it is.”  But the word chromophore is not quite a meaningless placeholder term for a thing we don’t understand (like dark matter).

Definition: A chromophore is a group of atoms within a larger molecule that are responsible for giving that molecule its color.  So, for example, chlorophyll molecules have chromophores in them that soak up red and blue light, thus giving chlorophyll its characteristically green appearance.

Etymology: Chromophore comes from two Greek words meaning “color” and “bearing.”  According to the Oxford English Dictionary, the earliest recorded usage of the word is in this 1879 dictionary of chemistry.  The word appears in a section about the chemical reactions used to make dyes.

Fun fact: just like the planet Jupiter, the oil pastels I used to draw this picture of Jupiter contain “chromophores.”

To say that Jupiter’s coloration is caused by chromophores is absolutely correct, but somewhat unhelpful.  It’s like asking “what caused that sound?” and being told “vibrations of the air.”  But, at least for now, it seems we don’t have a better answer.  To the best of my knowledge, we still don’t know which chemicals, specifically, are responsible for giving Jupiter his distinctive coloring (though Jupiter researchers have a lot of plausible-sounding guesses).

But whatever those chemicals are, they must contain chromophores.  Almost by definition, that must be true.

Shameless Self Promotion Time: Looking for Jupiter T-shirts, Jupiter notebooks, or other Jupiter-themed stuff?  Click here to check out all the Jupiter-related products available in the Planet Pailly store on Redbubble!

Is There Life on Earth?

Hello, friends!

Let’s imagine some space aliens are cruising by our Solar System.  They turn their scanners on our planet and see… what?

Among other things, they’d notice that Earth’s landmasses are partially covered with a strange, green-colored substance.  Of course, you and I know what that green substance is.  It’s chlorophyll.  But would those extraterrestrial observers, who have no prior knowledge of our planet, be able to figure that out?  Even if they did, would they realize what chlorophyll is used for?  Maybe.  Probably not, though.

Which brings me to my all-time favorite scientific paper: “A search for life on Earth from the Galileo spacecraft,” by Carl Sagan et al.  I love this paper in part because it’s so clearly and concisely written, with jargon kept to a minimum.  Sagan was, after all, a talented science communicator.  But I also love this paper because its conclusions are so shocking, so eye-opening.

In 1990, NASA’s Galileo spacecraft turned all its high-tech instruments toward Earth and detected… not much, actually.  Galileo did pick up radio broadcasts emanating from the planet’s surface.  Aside from that, though, Galileo’s data offered highly suggestive (but also highly circumstantial) evidence on Earthly life.  The lesson: finding life on other planets is hard.  Even using our very best equipment, it was hard for NASA to detect signs of life right here on Earth!

At least that’s what I got out of reading Sagan’s Galileo experiment paper.  And based on various commentaries I’ve read or heard about this paper, that seems to be the lesson other people got out of it too.  So I was surprised to hear Sagan himself, approximately seven-and-a-half minutes into this interview, saying the exact opposite.

We’ve flown by some sixty worlds.  We claim that we haven’t found life anywhere, and that that is a significant result.  That is, that we would have found life had it been there.  But this has never been calibrated.  We’ve never flown by the Earth with a modern interplanetary spacecraft, all instruments on, and detected life here.  And so Galileo, because of this peculiar gravity assist VEEGA trajectory, permits us to do that.  And as I’ll describe tomorrow, we find life five or six different ways, including intelligent life.  And this then means that the negative results that we find elsewhere are, in fact, significant.

I’ve been puzzled by this for a while now, but I think I’ve finally figured out why Sagan would say this.  It’s politics.

On the one hand, scientists need to understand the challenges they’ll face (including the limitations of their own equipment) in searching for life on other worlds.  That really is, I think, the purpose of the Galileo experiment paper.  On the other hand, it would not do to say on public television, to cantankerous taxpayers and the listening ears of Congress, that NASA spends millions of dollars on space probes that are not even capable of detecting life right here on Earth.

Space exploration is expensive.  And like all expensive types of research, sooner or later the researchers involved have to learn how to play politics.

Sciency Words: Safety Ellipse

Hello, friends!  Welcome to Sciency Words, a special series here on Planet Pailly where we talk about those wild and crazy words scientists use.  Today’s Sciency Word is:

SAFETY ELLIPSE

I don’t know about you, but when I’m trying to dock my shuttle pod with another spaceship, I like to take a few long, leisurely loops around that other spaceship first.  You know, like this:

Spaceships are pretty!  Who wouldn’t want to get a good look at them from every conceivable angle before completing docking maneuvers?  But it turns out that circling round and round a spaceship like this is not just for admiring the view.  It’s also for safety!  As explained in this paper:

A “safety ellipse” is an out-of-plane elliptical periodic relative motion trajectory around the primary spacecraft such that the trajectory never crosses the velocity of the primary.

That clear things up?  No?  Okay, how about a quote from this paper instead:

This paper defines a safe trajectory as an approach path that guarantees collision avoidance in the presence of a class of anomalous system behaviors.

Still confused?  Here’s a short video demonstrating what a safety ellipse (a.k.a. a safe trajectory) looks like:

Basically, if your shuttle pod experiences engine failure or any other major malfunction, flying in a safety ellipse ensures that you will not collide with the ship you were trying to dock with.  At least not for a good, long while.

I first heard about this term the other day while watching the livestream of the SpaceX Dragon capsule approaching and docking with the International Space Station.  Several times, the livestream commentators mentioned that Dragon was utilizing a “24 hour safety ellipse” or “24 hour safe trajectory,” meaning that if anything went wrong, mission control would have at least 24 hours to fix it before Dragon and the I.S.S. collided.

So remember, friends: the next time you’re going to dock with another spacecraft, do that out-of-plane elliptical periodic relative motion thing.  In other words, circle around the other ship a few times before making your final approach to dock.  It’s for safety reasons.

P.S.: It’s also for enjoying the view.  Spaceships are pretty!

No Gospel Truth in Science

Hello, friends!

So there’s this notion in the popular press that when a new scientific paper comes out, that paper should be taken as the final definitive word on an issue.  Science has spoken.  This is a scientific fact now.  But that is not how science works.

When new research is published, you should expect there will be followup research, and then that followup research will be followed up by even more research.  A new scientific paper really shouldn’t be seen as a proclamation of fact but rather as the beginning of a dialogue among scientists, or perhaps as the continuation of a dialogue that’s already in progress.

The recent detection of phosphine in the atmosphere of Venus has turned out to be a fantastic example of this ongoing dialogue in action.  The initial research was published in two separate papers (click here or here).  Basically, astronomers found the spectral signature of phosphine (PH3) in the Venusian atmosphere, and they were at a loss to explain where all that phosphine could be coming from.

Based on everything we currently know about Venus, those two papers tried to rule out several possible explanations.  Such a large quantity of phosphine could not be created by Venus’s atmospheric chemistry.  It could not be spewing out of volcanoes on Venus’s surface.  It could not be delivered to Venus by asteroids or comets.  One very intriguing possibility that could not be ruled out: maybe there’s life on Venus.  On Earth, phosphine is produced almost exclusively by living things.

But those two papers were not the definitive final word on the matter.  A dialogue had begun.  Soon, followup research came out suggesting that phosphine could be spewing out of volcanoes after all.  It would still be pretty shocking to discover that Venus has enough active volcanoes to produce that much atmospheric phosphine—but it be nowhere near as shocking as discovering Venus has life.

And then even more followup research came out with this paper, which points out possible errors in the original research and suggests that we may be dealing with a false positive detection.  Venus might not have phosphine after all, or maybe it doesn’t have as much as originally believed.

And the dialogue continues.  More research will come.  More responses will be published, and then there will be responses to those responses, and so forth until the scientific community reaches some sort of consensus about this Venusian phosphine business.  And even then, that scientific consensus still might not be the 100% final word on the matter.

Based on the way the popular press reports science news, you could easily get the impression that scientific papers should be treated as gospel truth.  You would be understandably confused, then, when one scientific paper comes out refuting the findings of another.  Subsequently, you may come to the conclusion (as a great many people apparently have) that science must not know anything at all.  Science just keeps contradicting itself, it seems.

But scientific papers are not meant to be taken as gospel truth.  They’re part of an ongoing back-and-forth dialogue.  So the next time you hear about some new scientific discovery on the news, remember that scientific papers are not intended to be bold proclamations of fact.  And when you hear about some new paper refuting older research, you’ll understand what’s going on.

What Color are All the Planets?

Hello, friends!

So as you know, Earth is “the Blue Planet” and Mars is “the Red Planet.”  By my math, that leaves us with six other planets in our Solar System that don’t have color-related nicknames.  Today, I’d like to try and fix that.

Jupiter was the toughest.  He’s actually lots of different colors: red, grey, white, orange… and then the Juno mission recently showed us that Jupiter’s polar regions are blue!  Of course Jupiter is most famous for being red in that one specific spot, but even the Great Red Spot changes colors from time to time, fading from red to pink to white before turning red again.

Anyway, those are my picks for the color-related nicknames for all the planets.  Do you agree with my picks?  Disagree?  Let me know in the comments below!

Sciency Words: VIRA

Hello, friends!  Welcome to Sciency Words, a special series here on Planet Pailly where we take a closer look at some interesting and new scientific term so we can expand our scientific vocabularies together.  Today’s Sciency Word is:

VIRA

You don’t mind if I do one more post about Venus, do you?  Venus is my favorite planet, after all, and the detection of phosphine (a possible biosignature!) in Venus’s atmosphere has got me really excited.  I’ve been reading lots of papers and articles about Venus lately, and many of those papers and articles mention something called VIRA.

VIRA stands for Venus International Reference Atmosphere.  VIRA is actually a book, originally published in 1985 by an international committee on space research.  The purpose of VIRA was to consolidate everything we knew about Venus’s atmosphere at that time into a single, easy to use reference guide.  As planetary scientist David Grinspoon describes it in his book Venus Revealed:

Although not exactly a best-seller, [VIRA] is a cherished reference among students of Venus’s atmosphere, and many a copy has become dog-eared and worn.  The tables and summaries of atmospheric data found therein are still the standard on Earth for Venus models, and the wide use of this standard allows us to make sure that we are comparing apples with apples, when making models and sharing new results.

One thing I don’t understand: why are Venus researchers still relying so heavily on a reference guide from 1985?  I’ve found several scientific papers (like this one or this one or this one) offering updates and improvements to VIRA.  And yet, unless I’m missing something (I feel like I must be missing something), it sounds like the original 1985 VIRA is still used as the gold standard for modeling Venus’s atmosphere.

Anyway, when people say we can’t explain where Venus’s phosphine comes from, in a sense, what they mean is that there’s nothing in VIRA that helps explain it.  So maybe the discovery of phosphine in Venus’s atmosphere will finally give scientists the push they need to update VIRA for the 21st Century.

P.S.: According to this paper, there’s also a Mars International Reference Atmosphere, or MIRA.  And I’m guessing there are similar reference atmospheres for other planets and moons in our Solar System as well.

Sciency Words: Global Resurfacing

Hello, friends!  Welcome back to Sciency Words, a special series here on Planet Pailly where we talk about those wild and crazy words scientists like to use.  Today on Sciency Words, we’re talking about:

GLOBAL RESURFACING

Venus is a mysterious planet.  Ever since the detection of phosphine in the Venusian atmosphere, the mystery du jour has been: does Venus support life?

We’ll circle back to Venus’s phosphine in a moment, but first I’d like to turn our attention to a different mystery concerning Venus: where did all of Venus’s craters go?

Impact craters are a common sight in the Solar System, especially here in the inner Solar System.  You’ll find plenty of craters on the Moon, of course.  You’ll find lots of them on Mercury, Earth, and Mars as well.  Some of those craters look fresh and new.  Others, due to weathering and erosion, look quite old—sometimes extremely old.

But the surface of Venus is relatively crater free, and the few craters we do find appear to be very, very recent.  In his book Venus Revealed, American planetary scientist David Grinspoon describes Venus’s craters thusly:

All the craters on Venus look unnaturally pristine.  Instead of blending into the volcanic plains that cover most of the planet, they seem planted on top as an afterthought, as though a crew had built a cheap movie-set planet and realized at the last minute that they had better throw in some craters.

Grinspoon goes on to explain how this might have happened:

Suppose that half a billion years ago something happened to Venus, wiping out all older craters.  Vast lava flows occurring simultaneously all over the planet would do the trick.  Then, if there has been relatively little surface activity since that time and Venus has been slowly collecting craters all along, things should look as they do.

This sudden event, when the whole surface of Venus got covered in fresh lava, is called “global resurfacing.” That’s a nice euphemism for an apocalyptic event, isn’t it?

Now this is important: Venus should have had little-to-no volcanic activity since her last global resurfacing event.  Otherwise, those younger, fresher, “unnaturally pristine”-looking craters would have gotten resurfaced too.  But in the last few years, circumstantial evidence has emerged suggesting that there are active volcanoes on Venus after all.

And now, finally, we circle back to the detection of phosphine in the Venusian atmosphere.  Some have suggested that that could be evidence of Venusian life.  But according to this preprint paper, that phosphine signature could also be interpreted as further evidence of volcanic activity.  Maybe global resurfacing was not a one-time event half a billion years ago.  Maybe resurfacing is an ongoing process that’s still happening today!

In a previous post, I said that Venus is about to teach us something we did not know: maybe it’ll be a biology lesson, or maybe it’ll be a chemistry lesson.  But now I think there’s a third possibility: maybe it’ll be a geology lesson.

P.S.: Special thanks to Mike Smith from Self Aware Patterns for sending that preprint paper my way.  At this point, it is just a preprint paper waiting to go through the peer review process, so don’t get too excited.  But the more I think about it, the more I feel like the authors of that paper are on the right track.