Tag: Venus

Venus Has Phosphine Fever

~ J.S. Pailly ~ 15 Comments

Hello, friends!

Over the last decade or so, Mars has been trying really hard to convince us that he can (and does) support life.  We’ve seen evidence of liquid water on the Martian surface, and traces of methane have been detected in the Martian atmosphere.  These things are highly suggestive, but none of that proves Martian life exists.

It would be nice if we knew of a chemical that clearly and unambiguously proved that a planet has life, wouldn’t it?  According to this paper published in Nature Astronomy, phosphine (chemical formula PH3) might be the clear and unambiguous biosignature we need.  Here on Earth, phosphine gas is a waste product produced by certain species of anaerobic bacteria.  It’s also produced by humans in our factories.  Either way, the presence of phosphine in Earth’s atmosphere is strong evidence that there’s life on Earth.

And according to that same paper from Nature Astronomy, astronomers have now detected phosphine on another planet.  No, it wasn’t Mars.

Okay, we humans do know of non-biological ways to make phosphine, but they’d require Venus to be a very, very different planet than she currently is.  For example, Venus would need to have a hydrogen-rich atmosphere, or Venus would have to be bombarded constantly with phosphorus-rich asteroids, or the Venusian surface would have to be covered with active volcanoes (more specifically, Venus would need at least 200 times more volcanic activity than Earth).

None of that appears to be true for Venus, so we’re left with two possibilities:

  • There is life on Venus.
  • There’s something we humans don’t know about phosphine, in which case phosphine is not the clear and unambiguous biosignature we hoped it was.

In either event, Venus is about to teach us something.  Maybe it’s a biology lesson.  That would be awesome!  Or maybe it’s a chemistry lesson.  Personally, I’m expecting it to be a chemistry lesson.  There must be some other way to make phosphine that we humans never thought of.

P.S.: Now I’m sure a lot of you are thinking: “Wait a minute, don’t Jupiter and Saturn have phosphine in their atmospheres too?”  You’re right.  They do, and we’ll talk about that in Wednesday’s post.

Sciency Words: Aerobiology

~ J.S. Pailly ~ 2 Comments

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

AEROBIOLOGY

You will find life pretty much anywhere you go on Earth.  Living things are in the water, on the land, and up in the air.

Aerobiology comes from three Greek words meaning “air,” “life,” and “the study of.”  So aerobiology is the study of airborne life, specifically airborne microbial life.  According to the Oxford English Dictionary, the term was first introduced in the late 1930’s.

I have to confess I am totally new to aerobiology.  I only found out about this term yesterday, and I don’t want anything I say to misrepresent the field.  But based on what I have read, it sounds like aerobiologists are primarily concerned with protecting public health from the spread of pollen and other allergens, as well as the spread of airborne diseases.

However, aerobiologists also study airborne microbes that are not a direct threat to human health—and this is the part that connects to the outer space stuff I normally write about.  For decades now, aerobiologists have known that algae and other common microorganisms can fly up into Earth’s atmosphere and travel great distances on the wind.  And according to this 2001 paper, microorganisms can (and do) remain active—growing and reproducing—inside the water droplets found in clouds.  As the authors of that 2001 paper explain it, we should start thinking of clouds as microbial habitats.

So what does this have to do with outer space?  Well, if clouds on Earth can serve as a habitat for microorganisms, then maybe microorganisms could exist in the clouds of some other planet.

And by some other planet, I mean Venus.

And by maybe, I mean stay tuned for Monday’s post.

Sciency Words: Syzygy

~ J.S. Pailly ~ 8 Comments

Hello, friends!  Welcome to Sciency Words, a special series here on Planet Pailly where we take a closer look at the definitions and etymologies of scientific terms.  Today on Sciency Words, we’re talking about the word:

SYZYGY

We’ve all seen pictures like this, with all eight planets lined up in a row:

And sometimes, on extra special occasions, the planets really do line up like that, or at least they come very close to it.  When this happens, we call it a grand syzygy.

The word syzygy traces back to ancient Greek.  It originally meant “yoked together,” as in: “The farmer yoked together his oxen before plowing the field.”  According to my trusty dictionary of classical Greek, the word could also mean “pair” or “union.”

Some closely related words in Greek referred to balance, teamwork, sexy times, etc.  And our modern English words synergy and synchronized have similar etymologies.  Basically, what all these words have in common is a sense of people or things coming together, in one manner or another.

For modern astronomers, syzygy means three or more celestial bodies coming together to form a straight line.  The most commonly cited example of this is the alignment of the Sun, Earth, and Moon that occurs during either a new moon or full moon, as observed here on Earth.

But an alignment doesn’t have to be perfectly straight to be called a syzygy, especially when we’re dealing with more than three objects.  According to this article from The New York Times, a syzygy of the Sun, Venus, Earth, Mars, Jupiter, and Saturn occured between March 25 and April 7, 1981.  The Sun and five planets came “within 2 degree of arc from a perfect straight line.”  Apparently that’s close enough.

But while that 1981 syzygy was pretty grand, it was not the grandest of grand syzygies.  The planets Mercury, Uranus, and Neptune were left out.  According to another article from The News York Times, a truly grand syzygy will happen on May 19, 2161, “[…] when eight planets (excluding Pluto) will be found within 69 degrees of each other […].”

So mark your calendars, friends!  You don’t want to miss the grand syzygy of 2161!

P.S.: And if you’re a Star Trek fan, you may recall that 2161 will be an auspicious year for another reason.  That’s the year when the United Federation of Planets will be founded—a political syzygy, one might say, occurring at the same time as an astronomical syzygy.

Something Worth Knowing

~ J.S. Pailly ~ 9 Comments

Hello, friends!

Today I’d like to share a very old video I found on YouTube.  It’s a series of man (and woman) on the street interviews where people are asked if they think we’ll find life on other planets.

According to the video description, this was filmed in 1962.  It’s interesting to me to hear people talk about the possibility of finding “vegetable” and/or “animal” life on Venus.  At that time, the Soviet Union’s Venera 1 spacecraft would have already visited Venus; however, due to a technical glitch, Venera 1 failed to transmit any data about Venus back to Earth.  So surface conditions on Venus were still unknown to us Earthlings.

But setting aside the Venus stuff in particular, in general people’s opinions about space exploration and extraterrestrial life have not changed much since 1962.  Some people are enthusiastically optimistic, others think it’s all nonsense, and a lot of people don’t seem to care one way or the other.

Then, of course, you get the one guy who swears he’s seen a U.F.O.  And then, of course, you get the guy who’s “working off the theory of the Bible,” where it says God only created life on one planet (F.Y.I., I’ve read the Bible too, and I don’t remember it ever saying that).  So again, not much has changed since 1962.

But my favorite is the woman at 1:40 who says she doesn’t expect we’ll find any life on Venus, but then goes on to say we’ll still find “something worth knowing.”  I’d say she was right on both counts!

Personally, I do think there’s life on other planets, and also on other moons (I’m looking at you, Europa).  But regardless of whether or not we find alien life out there, we should absolutely keep searching and keep exploring.  I suspect we will continue to learn all sorts of things that are worth knowing!

Next time on Planet Pailly, we’ll learn how to dance like binary stars.

Sciency Words: Stagnant Lid

~ J.S. Pailly ~ 6 Comments

Sciency Words: (proper noun) a special series here on Planet Pailly focusing on the definitions and etymologies of science or science-related terms.  Today’s Sciency Word is:

STAGNANT LID

Here on Earth, we have earthquakes.  Lots and lots of earthquakes.  And that’s very odd.

Maybe we should be thankful for all those earthquakes.  Our planet’s system of plate tectonics is unique in the Solar System.  Frequent earthquakes are a sign that Earth’s tectonic plates are still moving, that our planet is still geologically healthy.  The alternative would be stagnant lid tectonics, and that’s something we Earthlings probably don’t want.

In this 1996 paper, planetary scientists V.S. Solomatov and L.N. Moresi coined the term “stagnant lid” to describe what was happening on Venus—or rather what was not happening.  Venus doesn’t have active plate tectonics.  Maybe she did once, long ago.  If so, Venus’s plates somehow got stuck together, forming a rigid, inflexible shell.

The term stagnant lid has since been applied to almost every other planetary body in the Solar System, with the obvious exceptions of the four gas giants, and the possible exceptions of two of Jupiter’s moons: Europa and Ganymede.

According to this paper from Geoscience Frontiers, neither Europa nor Ganymede have truly Earth-like plate tectonics, but something similar may be happening.  The authors of that paper refer to the situation on Europa and Ganymede as “fragmented lid tectonics” or “ice floe tectonics.”  The upcoming Europa Clipper and JUICE missions should tell us more about how similar or different this is to Earth’s plate tectonics.

A stagnant lid does not necessarily mean that a planet or moon is geologically dead.  Venus and Io both have active volcanoes, for example, and it was recently confirmed that Mars has marsquakes.  But none of these stagnant lid worlds seem to be as lively as Earth—and I mean that in more ways than one.

If you buy into the Rare Earth Hypothesis, plate tectonics is one of those features that makes Earth so rare. Plate tectonics is something Earth has that other planets don’t, and thus it may be an important factor in why Earth can support life when so many other worlds can’t.

Sciency Words A to Z: Unknown Absorber

~ J.S. Pailly ~ 7 Comments

Welcome to a special A to Z Challenge edition of Sciency Words!  Sciency Words is an ongoing series here on Planet Pailly about the definitions and etymologies of science or science-related terms.  In today’s post, U is for:

THE UNKNOWN ABSORBER

If there’s one thing worth remembering from all this astrobiology stuff, it’s that life begins with chemistry.  All life in the universe, no matter how strange and exotic it may seem to us Earthlings, must depend on chemistry.  And I don’t know many places that are more chemically active than the planet Venus.  So is Venus a good place to go looking for alien life.

To quote from David Grinspoon’s book Venus Revealed, “Where life is concerned, Venus is consistently voted ‘least likely to succeed.’”  Sure, Venus is chemically active, but in a way that will violently tear apart complex organic molecules.

However, Grinspoon has the temerity to go ahead and speculate—and he makes it abundantly clear this is pure speculation—about the kinds of organisms that might call Venus home.  And that speculation focuses on a mysterious substance found in the Venusian clouds, a substance that has long been called the unknown near-U.V. absorber, or simply the unknown absorber.

In the field of spectroscopy, every chemical is known to absorb very specific wavelengths of light.  When light is spread out into a spectrum, as with a prism, you get a sort of unique barcode that you can use to identify chemicals.

A very simple “barcode” representing hydrogen.

If you’ve ever wondered how astronomers know which chemicals are found in space, or on other planets, this is how they do it.

In 1974, NASA’s Mariner 10 spacecraft sent us our first ever close-up photos of Venus.  In the visible part of the spectrum, there were no real surprises, but photos taken in ultraviolet showed that something was absorbing U.V. light like crazy, producing a spectroscopic barcode that nobody recognized.

In his speculation about life on Venus, Grinspoon mentions another chemical with a complex, hard-to-identify spectral barcode: chlorophyll, the chemical that makes photosynthesis possible here on Earth.  I say hard-to-identify… it’s not hard for us to identify, because we already know what it is.  But if extraterrestrial observers were studying Earth’s spectrum, chlorophyll would have them very confused—almost as confused as we were by Venus’s unknown absorber.

So could the unknown absorber be a chlorophyll-like molecule? Could this be the first evidence of air-born bacteria, drifting around in Venus’s cloudbanks, performing their own version of photosynthesis?  Maybe, Grinspoon tells us in Venus Revealed.  But that book came out in 1997.  In 2016, this paper was published identifying Venus’s unknown absorber as disulfur dioxide.

On a personal note, I wrote a blog post about Venus’s formerly unknown absorber before, and my post got the attention of the lead author of that 2016 paper.

But even though the mystery of Venus’s unknown absorber may have been laid to rest, I think this still served as a valuable lesson about what we should be looking for out there in the cosmos. Someday, another unknown absorber, with another weird spectral barcode, may be the thing that leads us straight to the discovery of alien life.

Next time on Sciency Words A to Z, the Martians better watch out.  The Vikings have landed on their planet!

Sciency Words A to Z: Goldilocks Zone

~ J.S. Pailly ~ 9 Comments

Welcome to a special A to Z Challenge edition of Sciency Words!  Sciency Words is an ongoing series here on Planet Pailly about the definitions and etymologies of science or science-related terms.  In today’s post, G is for:

GOLDILOCKS ZONE

Once upon a time, there was a little girl from outer space who came to visit the Solar System.  Her name was Goldilocks.  First, she landed on Mars, but she didn’t like it there.  It was too cold.  Then she tried to land on Venus, but she didn’t like it there either. It was too hot—way too hot.  And then finally, Goldilocks landed her spaceship on Earth.  When she came out of the airlock and walked down the landing ramp, she said to the astonished Earthlings, “Ah yes, this planet is just right!”

At least that’s how my version of the Goldilocks story goes.

Anyway, the concept of a Goldilocks zone (also known as a habitable zone, continuously habitable zone, or circumstellar habitable zone) is pretty simple.  Fairy tale simple, you might say.  The Goldilocks zone is the region of space around a star where liquid water can exist on a planet’s surface.  And as you know, if a planet has liquid water on its surface, then it could have life!

For a long time, our search for alien life has focused almost exclusively on Goldilocks planets.  But there are problems with limiting our search in that way.

In my post on carbon chauvinism, I told you there are other chauvinisms that astrobiologists have to deal with. One of them is water chauvinism, the presumption that water is necessary for life.  Another is surface chauvinism, the presumption that life can only exist on a planet’s surface.  Our obsession with Goldilocks zones is largely based on those two chauvinisms.

But looking to the moons of Jupiter and Saturn, we’ve already learned that there is more liquid water outside the Goldilocks zone than in it!  Several of those moons have vast oceans of liquid water beneath their surface, with only a relatively thin crust of ice overtop.  These subsurface oceans might be ideal environments for alien life.  So much for our surface chauvinism.

And then there’s Titan, a moon of Saturn, which has lakes of liquid methane and ethane on its surface.  Could those liquid hydrocarbons serve as a substitute for water in an alien biochemistry?  We don’t know.  It’s possible.  We certainly shouldn’t rule that possibility out.  And thus, so much for our water chauvinism.

To quote from Exoplanets by Michael Summers and James Trefil, “[…] the current focus on finding a Goldilocks planet amounts to a search for the least likely location of water and, presumably, life.”  I think there’s a bit of hyperbole in that statement, but I agree with the general point.  There are probably far more worlds in our galaxy like Europa, Enceladus, or Titan than there are like Earth.

Next time on Sciency Words A to Z, we’ll crack the surface of one of those icy moons and see what might be hidden in those dark, extraterrestrial depths.

Where Are the Aliens?

~ J.S. Pailly ~ 15 Comments

I fell way behind on my science and space exploration research last year.  I now have a tall pile of to-be-read books and papers in my reading room.  But I’m now starting to catch up, beginning with this paper on the atmospheres of Earth-like planets.

As explained in this article from the Planetary Society, the goal of this paper is to start creating a guidebook for finding planets that might be home to alien life.  And based on what the paper says early on, it sounds like there are plenty of “habitable Earth-like planets” out there to be found!

If we’re looking only at red dwarf stars, which are the smallest and most common of stars, about 30% of them should have a habitable Earth-like planet orbiting them.  And between 5 and 20% of orange, yellow, and yellow-white dwarf stars should have habitable Earth-like planets too.  Our own Sun, by the way, is a yellow dwarf star.

Statistically speaking, this means we should find another Earth orbiting a red dwarf within only 2 parsecs of us.  And there should be another another Earth orbiting an orange, yellow, or yellow-white dwarf within 6 parsecs.  I feel like that’s surprisingly close, at least in the grand scheme of our universe.

Except when astronomers talk about Earth-like planets, what they’re actually describing does not necessarily sound much like Earth.  Any planet that’s about the same size and mass as Earth can be called Earth-like, and by that standard Venus is about as Earth-like as any planet can be, aside from Earth itself.

And when this paper talks about habitable Earth-like planets, I’m pretty sure all the authors mean are planets within the habitable zones of their parent stars.  But just because a planet orbits within a habitable zone does not mean that planet is truly habitable.  Again, look at Venus.

So when we do find a “habitable Earth-like planet” within 2 or 6 parsecs of us, how will we know we’re looking at another Earth and not another Venus?  That’s a tricky question.  Maybe it would help to think about the problem from a different perspective.  You see, while we humans are having a really difficult time finding alien life, the aliens may also be having a very difficult time finding us.

More on that in the next post!

My Favorite Planet: Venus

~ J.S. Pailly ~ 33 Comments

I’m thinking of doing a few of these kinds of posts, if people are into it: my favorite planet, my favorite moon, my favorite asteroid… that sort of thing. Today I’d like to tell you a little about Venus, my favorite planet in the Solar System and also the best chemistry teacher I’ve ever had.

Venus has been my favorite planet for a long time now.  I used to say to people, “It’s because Venus has the most personality.  It’s the personality of a serial killer, but still… so much personality!”

It’s true that Venus is excessively, unreasonably, incomprehensibly hostile toward life.  I mean, all the planets are dangerous (even Earth is a dangerous place in its own ways), but if you ever go to Venus, Venus will try to kill you at least a dozen different ways before you touch the ground.  And when your crushed and crispy remains do reach the ground, Venus will try to kill you again in at least a dozen more ways.

No other planet is so creative and so gleefully enthusiastic about murder.  As a science fiction writer, one of my goals in life is to set a novel on Venus or a Venus-like planet, because no other setting makes for such a deadly antagonist.

But upon further reflection, I think there’s a better reason why Venus holds such a special place in my heart.  I’ve done a lot of space-related research over the years.  It’s all part of my ongoing quest to become a better science fiction writer.  Venus was the first planet to really challenge me intellectually.

Why is Venus so deadly?  In many ways, Venus is Earth’s twin.  The two planets are about the same size, they have almost the same surface gravity, and their chemical compositions are similar. Venus is slightly closer to the Sun, but it’s still within our Solar System’s habitable zone.  So what gives?

It was hard work getting the kind of answers I was looking for.  Venus forced me to learn a lot of new things.  In particular, I had to learn more about chemistry, a subject that I despised in school and had really hoped I could avoid.  But in struggling to understand Venus’s sulfur chemistry, and later its carbon chemistry, I was rewarded not only with a deeper understanding of one planet but of how planets in general are put together, and how they each end up with their own distinct “personalities.”

Picking a favorite anything is obviously a subjective thing. For me, studying Venus was an eye-opening experience in ways I never would have expected.  For that, I’m forever grateful to the planet Venus, and Venus will always be my favorite planet.

So what’s your favorite planet?  If you say “Earth, because I live there,” I’m going to be a little disappointed.  But whatever your favorite planet is, and whatever your reasons for that, please share in the comments below!

NASA’s Next Flagship Mission

~ J.S. Pailly ~ 15 Comments

Let’s imagine you’re NASA. You have two big flagship-class missions coming up: one to search for life on Mars (launcing in 2020) and another to search for life on Europa (launching in 2022). These flagship missions are big, expensive projects, so Congress only lets you do one or two per decade.

After 2022, the next flagship mission probably won’t launch until the late 2020’s or early 2030’s, but still… now is the time for you to start thinking about it. So after Mars and Europa, where do you want to go next? Here are a few ideas currently floating around:

  • Orbiting Enceladus: If you want to keep looking for life in the Solar System, Enceladus (a moon of Saturn) is a good pick. It’s got an ocean of liquid water beneath it surface, and thanks to the geysers in the southern hemisphere, Enceladus is rather conveniently spraying samples into space for your orbiter to collect.
  • Splash Down on Titan: If there’s life on Titan (another moon of Saturn), it’ll be very different from life we’re familiar with here on Earth. But the organic chemicals are there in abundance, and it would be interesting to splash down in one of Titan’s lakes of liquid methane. If we built a submersible probe, we could even go see if anything’s swimming around in the methane-y depths.
  • Another Mars Rover: Yes, we have multiple orbiters and rovers exploring Mars already, but some of that equipment is getting pretty old and will need to be replaced soon. If we’re serious about sending humans to Mars, it’s important to keep the current Mars program going so we know what we’re getting ourselves into.
  • Landing on Venus: Given the high temperature and pressure on Venus, this is a mission that won’t last long—a few days tops—but Venus is surprisingly similar to Earth in many ways. Comparing and contrasting the two planets taught us how important Earth’s ozone layer is and just what can happen if a global greenhouse effect get’s out of control. Who knows what else Venus might teach us about our home?
  • Orbiting Uranus: This was high on NASA’s list of priorities at the beginning of the 2010’s, and it’s expected to rank highly again in the 2020’s. We know next to nothing about Uranus or Neptune, the ice giants of our Solar System. Given how many ice giants we’ve discovered orbiting other stars, it would be nice if we could learn more about the ones in our backyard.
  • Orbiting Neptune: Uranus is significantly closer to Earth than Neptune, but there’s an upcoming planetary alignment in the 2030’s that could make Neptune a less expensive, more fuel-efficient choice. As an added bonus, we’d also get to visit Triton, a Pluto-like object that Neptune sort of kidnapped and made into a moon.

If it were up to me, I know which one of these missions I’d pick. But today we’re imagining that you are NASA. Realistically Congress will only agree to pay for one or two of these planetary science missions in the coming decade. So what would be your first and second choices?