Encyclopedia Galactica

I was an undergraduate when the original Cosmos first aired.

It was back in 1980, and I still remember being blown away by it all -- the melding of science with animation and gorgeous music, and Carl Sagan's lyrical, almost poetic way of expressing his enduring love for astronomy.  My friends and I always waited excitedly for the next episode to air, and the day afterward spent an inordinate amount of time chatting about what we'd learned.

One of the episodes that resonated the most strongly with me was entitled "Encyclopedia Galactica."  Sagan predicted a day when we'd know so much about the universe that we'd have an encyclopedia of alien planets, each page of which would be accompanied by a list of their physical characteristics -- and types of life forms.  He was unequivocal in his belief that we were not alone in the universe, and that in fact life would turn out to be common.  Not, perhaps, "life as we know it, Jim" -- and much of it almost certainly pre-technological -- but life, he thought, would turn out to be pretty much everywhere we looked.

In the forty-five years since it aired, our detecting equipment has gotten better and better, but we're still up against the Fermi Paradox -- that famous quip from physicist Enrico Fermi who, when told that life was likely to be common in the universe, said, "Then where is everybody?"  Long-time readers of Skeptophilia may recall that a few years ago I did a deeper dive into the Fermi Paradox and the infamous "three f's," but the fact remains that despite getting better and better at astronomy and astrophysics, we still have no incontrovertible evidence of extraterrestrial life (intelligent or otherwise).

But extrasolar planets?  Those are kind of a dime a dozen.  As of this month, there have been a bit over six thousand exoplanets conclusively identified, and some of them have challenged our models of what planets can be.  (I took a look at a few of the weirder ones in a post earlier this year.)  So even if we don't yet have aliens in our back yard, there's been a lot of really cool information discovered -- three examples of which have just come out in the past couple of weeks.

No Andorians yet, more's the pity.

The first is about the TRAPPIST-1 system, which was one of the first multi-planet systems discovered.  Not only that, it has four planets in the "Goldilocks zone" -- the region around the host star that is "just right" for having temperatures where water could be in its liquid state.  (This doesn't mean there is water; just that if other factors were favorable, there could be liquid water.)  Not only that, but we lucked out that TRAPPIST-1 is fairly close (a little over forty light years away, in the constellation of Aquarius), and that its planets' orbits are aligned so that from our perspective, they cross in front of their host star, allowing astrophysicists to use the transits to take a stab at the composition of their atmospheres.

The outstanding YouTuber Dr. Becky Smethurst did a wonderful video explaining how this all works (and why the planet TRAPPIST-1d probably doesn't have an atmosphere), but a capsule summary is that when the planet passes in front of the star, its light passes through the planet's atmosphere (if it has one), and any gases present absorb and scatter characteristic frequencies of light.  Compared to the unobstructed spectrum of the star, those frequencies are then missing (or at least diminished in intensity), and from that information astrophysicists can deduce what might be present in the atmosphere.

Well, the other three planets in the habitable zone -- TRAPPIST-1b, c, and d -- have pretty conclusively been shown to lack an atmosphere.  So it all hinges on 1e, the farthest one out, and a study at the University of Bristol, using data from the James Webb Space Telescope, has said that it cannot rule out the presence of an atmosphere on that one.  Not a ringing endorsement, that, but at least not a categorical no -- so we'll keep our eyes on TRAPPIST-1e and hope future studies will give us good news.

The other two stories are about "rogue exoplanets" -- planets out there floating in space that don't (or at least, don't now) orbit a star.  Whether they formed that way, or started out in a stellar system and then were ejected gravitationally, is unknown (and may well be different in different cases).  These, for obvious reasons, are considered poor candidates for life, but they still are pretty amazing -- and the fact that we know about them at all is a tribute to our vastly improved ability to detect objects out there in interstellar space.

The first one, CHA-1107-7626, is currently accreting material like mad -- something not seen before in an exoplanet, rogue or otherwise.  It is estimated to be between five and ten times the mass of Jupiter, so on the verge of being a "brown dwarf" -- a superplanet that has sufficient mass and pressure to fuse deuterium but not hydrogen.  They emit more energy than they absorb, but don't quite have enough for the nuclear furnace to turn on in a big way.

But if CHA-1107-7626 keeps going the way its going, it may get there.  It's hoovering up an estimated Jupiter's worth of material every ten million years or so, which is the largest accretion rate of any planet-sized object ever observed.  So what we might be witnessing is the very earliest stages of the formation of a new star.

The final study is about the rogue exoplanet SIMP-0136, which came out of Trinity College Dublin and again uses data from JWST.  But this exoplanet is bizarre for two different reasons -- it has vast storms of what amounts to liquid droplets of sand... and it has auroras.

Once again, I'm staggered by the fact that we could detect this from so far away.  The temperature of the surface of the planet is around 1,500 C -- hotter than my kiln at full throttle -- and it has three hundred kilometer per hour winds that blow around bits of molten silica.  But most peculiar of all, the planet's atmosphere shows the characteristic polar light flashes we see down here as auroras.

What's weirdest about that is that -- at least on Earth -- auroras are caused by solar activity, and this planet isn't orbiting a star.  The way they form down here is that the solar wind ionizes gases in the upper atmosphere, and when those ions grab electrons, and the electrons descend back to the ground level, they emit characteristic frequencies of light (the same ones, not coincidentally, that are swiped by gases in the atmospheres of planets during transits).  Red for monoatomic oxygen, green for diatomic oxygen, blue for molecular nitrogen, and so on.

What is ionizing the gases on SIMP-0136?  Astrophysicists aren't sure.  Sandstorms here on Earth can certainly cause static electrical discharges (what we laypeople refer to as "bigass lightning bolts"), so it's possible we're seeing the light emitted from interactions between the molten silica and whatever gases make up the planet's atmosphere.  But it's too soon to be sure.

So even if we haven't yet discovered Skithra or Slitheen or Sontarans or whatnot, we're still adding some pretty amazing things to our Encyclopedia Galactica.  Carl Sagan, as usual, was prescient.  As he put it, "Somewhere, something incredible is waiting to be known."

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ET, call Lexington

If you needed more evidence that we're living in surreal times, some scientists have collaborated with the Tourism Board of Lexington, Kentucky to send a message to aliens inviting them to come to the city for a visit.

The message was sent via infrared laser toward TRAPPIST-1, a multi-planet system about forty light years from Earth.  Astonishingly, they actually got permission from the Federal Aviation Administration -- not a government office known either for its flexibility or its sense of humor -- to beam the message out.  The message, in coded bitmap form, contained information regarding the intent of the transmission, some photographs of the Lexington area, and an audio recording of blues musician Tee Dee Young.

"The bitmap image is the key to it all," said Andrew Byrd, a linguistics expert at the University of Kentucky, who was one of the scholars involved in the project.  "We included imagery representing the elements of life, our iconic Lexington rolling hills, and the molecular structure for water, bourbon, and even dopamine because Lexington is fun."

It also contained the message, "Come to Lexington!  We have horses and bourbon.  Just don't eat us."

I feel obliged to interject here that I'm not making any of this up.

The Lexington Tourism Board's promo art for the project, which I also did not make up

Regular readers of Skeptophilia know that the possibility of alien life -- perhaps intelligent life -- is a near-obsession with me, but I'm not sure this is really the way to go about trying to contact it.  While TRAPPIST-1 isn't a bad choice given the fact that it's fairly close and we know it has seven planets, there's no indication any of them host life.  Four of the planets appear to orbit within the star's "Goldilocks Zone," where the temperatures are "just right" for water to exist in liquid form, but that doesn't mean the planets have liquid water, or even atmospheres.  The fact that the planets have such tight orbits -- the farthest one only has an orbital radius six percent of Earth's, and orbits its star in nineteen days -- suggests they're probably tidally locked, meaning the same side of the planet always faces the star.  (I wrote about the difficulty of life evolving on a tidally-locked planet a year ago, if you're curious to read more about it.)

Then there's the problem of waving hello at aliens who might be vastly more powerful than we are and would respond by squashing us.  Stephen Hawking addressed this in stark terms back in 2010, saying, "We don't know much about aliens, but we know about humans.  If you look at history, contact between humans and less intelligent organisms have often been disastrous from their point of view, and encounters between civilizations with advanced versus primitive technologies have gone badly for the less advanced.  A civilization reading one of our messages could be billions of years ahead of us.  If so, they will be vastly more powerful, and may not see us as any more valuable than we see bacteria."

Of course, if there are intelligent aliens out there, they probably already know about us.  At least the ones under 104 light years away do, because there's an expanding bubble of radio and television transmissions sweeping outward from us at the speed of light that began with the first commercial radio broadcast in 1920.  Assuming any aliens on the receiving end are at least as smart and technologically capable as we are, they're probably already decoding those transmissions and listening to Fibber McGee and Molly and watching Lost in Space, after which they will definitely think we're no more valuable than bacteria.

The last issue -- and this may be the good news, here, if you buy what Hawking said -- is that because TRAPPIST-1 is forty light years away, any aliens who might live there won't receive the message until 2064, and the earliest we could get a response is 2104.  Even if they have some kind of superluminal means of travel and jumped into their spaceships as soon as they got the message, it wouldn't be until the 2060s that they could even potentially get here.  

At least the Lexington Tourism Board has a good window of time to get their hotels ready for the influx of alien tourists.  And if they turn out to be hostile, at that point (if I'm still alive) I'll be over a hundred years old, and I figure that an alien laser pistol blast to the face is about as dramatic a way to check out as I could ask for, so I suspect I'll be fine with the Earth being invaded regardless which way it goes.

So the Lexington Tourism Board's efforts fall squarely into the "No Harm If It Amuses You" department.  And I guess the more time people spend focusing on this sort of thing, the less they'll spend dreaming up new and different ways to be awful to each other.  So as far as that goes, I'm all for sending messages to the stars.

Even if the best things you can think of to talk about are horses, bourbon, and dopamine.

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Saturday science shorts

Because I am totally disheartened by the news, frustrated by the lack of critical thinking everywhere I look, and also because my blender exploded when I was making breakfast this morning and splattered orange juice and half-processed fruit over every square inch of the kitchen including myself, I am retreating to my happy place, namely: cool stuff in science news.

Let's start with a story from astronomy about something that is a near-obsession with me; the possibility of life on other planets.  This particular research involves the star system TRAPPIST-1, discovered last year and found to have not one, not two, but seven planets, three of which are in the so-called "Goldilocks Zone" (where the temperature is juuuuust right for water to be in liquid form).  Of course, that doesn't guarantee that water's there, just that if it was, it would be liquid, which scientists surmise would be a pretty good indicator of the likelihood of the probability of hosting life.

Now, researchers have found that all of the TRAPPIST-1 planets do have water -- in some cases, up to five percent of their mass.  So the three in the habitable zone might well be water-worlds.  All of which reminds me of the planet Kamino from The Phantom Menace, which otherwise was a dreadful movie, but I have to admit reluctantly that this part was cool.

Here's what we know about the TRAPPIST-1 system, although keep in mind that the illustrations of the planets are artists' renditions of what they might look like:

[image courtesy of NASA/JPL]

So that's pretty wicked cool.  The difficulty, of course, is that even if they did host life, it'd be hard to see that if the inhabitants had not advanced technologically to the point that they were sending out signals.  But even that hurdle might not be insurmountable -- as I wrote in a post a couple of weeks ago, astronomers are now trying to figure out if life is present on an exoplanet by the composition of its atmosphere.

Then, from the realm of biology, we have a study elucidating how those tiny jet fighters of the avian world -- hummingbirds -- maneuver as well as they do.

A group led by Roslyn Dakin and Paolo Segre of the Smithsonian Conservation Biology Institute of Ottawa examined hundreds of hours of high-speed video of hummingbirds in flight, looking at twenty-five different species and examining how they do their amazing aerobatics, including pivoting while in flight, hovering, and moving in an arc so narrow that it almost defies belief.  

The research took them to remote places in Panama, Costa Rica, and my favorite country of Ecuador -- the tiny nation that is host to 250 different species of hummingbirds, including the preternaturally beautiful Violet-tailed Sylph (Aglaiocercus coelestis):

Where I live, we have a paltry one species, albeit a beautiful one -- the Ruby-throated Hummingbird.  So it's no wonder the researchers decided to head south.

Another hummingbird researcher, Christopher Clark of the University of California-Riverside, has said that the new study is like moving from analyzing individual gestures of a ballerina to looking at how the moves fit together.  "Now," Clark says, "we're putting together the entire dance."

Last, some scientists at the University of Zurich have for the first time been able to see new neurons being formed in the brains of embryonic mice.  

Starting out by tagging 63 neural stem cells in the hippocampus, Sebastian Jessberger and his team were able to watch as the neurons grew outward and formed connections (synapses) with neighboring neurons.  What was most intriguing was that some of the new neurons had short lives -- perhaps acting as scaffolding for the developing brain and then self-destructing (undergoing apoptosis) when their task was complete.

Amongst these tagged cells, the red ones are the newest, orange next, and continuing through yellow and green (the oldest cells).

What is most exciting about this is that being mammals, it's expected that the knitting together of the embryonic human brain probably proceeds in a very similar fashion.  So what Jessberger et al. are doing might well inform us regarding how our own neural systems form.

So there you have it -- three cool new developments in the world of science.  Which has cheered me up considerably.  That's a good thing, considering the fact that now I have to go clean my kitchen, which I'm definitely not looking forward to.

Music of the spheres

When I went to graduate school, I think the most surprising thing for me was that we were supposed to think creatively about science.  While I had, for the most part, excelled in my science classes in high school and college, they had mostly required me only to master concepts and then be able to demonstrate my mastery on an exam.  I had never had to synthesize, put ideas together in a novel way, apply concepts from one field in an entirely different one.  Nor had I been expected to critique ideas or arguments; I had merely been expected to understand them.

So my leap into the Graduate School of Oceanography at the University of Washington was a bit of a rude awakening, and was (on the whole) kind of a failure.  I was not, at that point in my life, prepared intellectually for the challenge of applying scientific ideas in a creative way, largely because I'd never had any practice in doing so.

No wonder, then, that I lasted exactly one semester in the School of Oceanography

I have since come to appreciate the role of creativity, lateral "outside of the box" thinking, and pure cleverness in approaching scientific questions.  I still suspect I wouldn't be very good at it -- on the whole, I think it was a good decision to leave the educational track headed toward research -- but at least I understand now that in science, the capacity for creative synthesis is as important as pure knowledge.

I ran into an especially good example of that yesterday, in a field that has always been a source of fascination for me; the study of exoplanets.  There have thus far been over a thousand exoplanets discovered, with new ones being reported all the time.  The most exciting part is when one is found that is in the "Goldilocks Zone" (not too hot, not too cold, juuuuuussst right), where liquid water can exist, and therefore where life is thought to be far more likely.

One of the most exciting planetary systems so far discovered is called "Trappist-1," and is about forty light years from Earth.  Trappist-1 has no less than seven Earth-sized planets, at least a few of which are thought to be in the habitable zone.  But the coolest thing about the Trappist-1 system is that an astrophysicist has explained the relative rates of revolution of the seven planets...

... using principles of harmony in music.

Artist's conception of the Trappist-1 system [image courtesy of the Spitzer Space Telescope and NASA/JPL]

What's funny about this is that famed astronomer Johannes Kepler nearly drove himself insane trying to show that the orbits of the planets in our Solar System were connected somehow to the "five Platonic solids" -- cube, octahedron, tetrahedron, dodecahedron, and icosahedron -- thereby proving that there was some divine order in the heavens rather than (as it appeared) the planets all orbiting at different distances in a seemingly random fashion.  He wrote a book called the Mysterium Cosmographicum (Secret of the Universe) elaborating on this theory.  (Kepler had evidently never heard that Brevity Is The Soul Of Wit, because the full title of his book is 46 words long, which is why everyone just calls it the Mysterium Cosmographicum.)

In any case, Kepler's attempt at forcing the Solar System into a pattern based on the five Platonic solids was a complete flop, and it was only after he abandoned this idea that he made the discovery for which he became famous -- that planets travel in ellipses, not circles, and that regardless of the distance they are from the Sun, their orbits sweep out equal areas in equal times.

In a discovery that would have warmed the cockles of Kepler's heart, a team of astronomers, led by Daniel Tamayo of the University of Toronto-Scarborough, just published a paper last week in Astrophysical Journal Letters suggesting that while the orbits of planets have nothing to do with the five Platonic solids, they do have something to do with the phenomenon of resonance -- when the oscillation of one body influences the oscillation of another.  Tamayo found that the seven planets around Trappist-1 are in stable orbits because they are in a resonance pattern that resembles the relationships between frequencies of notes in a chord.  For example, the second planet in the system completes five orbits in the time taken for the innermost planet to make eight; the fourth planet makes two revolutions every time the third one makes three; and so on.  The combined effect of this is to make the entire system operate in a regular, predictable fashion.

The coolest part of this is that Tamayo turned the periods of revolution for all seven planets into musical notes, with the relationships between the pitches representing the ratios between the period length.  You can hear his recording of the musical representation of the Trappist-1 system at the link above.

You'll be listening to the actual music of the spheres.

"I think Trappist is the most musical system we'll ever discover," said Matt Russo, who is a member of Tamayo's team as well as being a musician, and who designed computer simulations of planetary systems in musical resonance (and ones that were not) to see if they remained stable over time.

Tamayo compared resonance in a planetary system to musicians in an orchestra.  "It's not enough for members merely to keep time," he said.  "Simulating the formation of a system in its birth disk is analogous to an orchestra tuning itself before playing.  When we create these harmonized systems, we find that the majority survive for as long as we run our supercomputer simulations."

So there you have it; a melding of music and astrophysics.  I find myself in awe of this sort of research, mostly because I can't imagine my coming up with an idea this creative myself.  So maybe it's best I decided on teaching and writing as a career.  I may not have much of a facility for connecting disparate concepts myself, but I certainly love to tell others about the delightful research of people who do.