Category: Space Science

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!

Which Planet Has the Weirdest Magnetic Field?

~ J.S. Pailly ~ 11 Comments

When I did my yearlong Mission to the Solar System series back in 2015, the planet Neptune stood out as having the weirdest and wackiest magnetic field.  Here’s a totally legit photograph from 1989 taken by the Voyager 2 space probe.  As you can see, Neptune is really confused about how magnetic fields are supposed to work.

But since 2015, science has learned more about the other three gas giants in our Solar System.  Neptune’s magnetic field is still really weird, but it’s no longer clear that it is the definitive weirdest.

  • Jupiter: Based on data from the Juno mission, it looks like Jupiter has three poles instead of two.  There’s a north pole, right about where you’d expect it to be.  Then the magnetic field lines emanating from the north pole connect to two separate south poles.  The first south pole is about where you’d expect a south pole to be. The other one is near the equator. Click here for more about Jupiter’s “non-dipolar” magnetic field.
  • Saturn: As Sherlock Holmes says in one of his many adventures, “Depend upon it, there is nothing so unnatural as the commonplace.” According to data collected during the Cassini mission’s Grand Finale, Saturn’s magnetic field is almost perfectly aligned with its rotation.  At first blush, that might seem quite normal.  Commonplace, even. Except no other planet’s magnetic field is so perfectly aligned.  Not even close.  Apparently planetary scientists didn’t think such a thing was even possible.  Click here for more about the “negligible tilt” of Saturn’s magnetic field.
  • Uranus: The planet Uranus is tipped over sideways, and its magnetic field is tipped over further still.  According to recent computer simulations, these two factors combine to cause Uranus’s magnetic field to tumble over itself “like a child cartwheeling down a hill,” as one researcher put it. This leads to a “periodic open-close-open-close scenario” where the solar wind can flow in toward the planet then suddenly be blocked, then suddenly flow in again, and then suddenly be blocked.  If these simulations are correct, the Uranian aurora may flick on and off like a light switch. Click here for more about the “topsy-turvy motion” of Uranus’s magnetic field.
  • Neptune: In 1989, Voyager 2 discovered that Neptune’s magnetic field is lopsided. The magnetic field doesn’t run through the planet’s core. Instead it runs through a seemingly random point about halfway between the core and the “surface” (by which I mean the topmost layer of the atmosphere).  Also, only one of the poles ends up being near the planet’s “surface.”  The other pole is buried somewhere deep in the planet’s interior.  For more about Neptune’s “badly behaved” magnetic field, click here.

If I had to choose, I’d probably still give Neptune the award for weirdest magnetic field.  But the competition is a lot tighter than it used to be.  Maybe the real lesson here is that gas giants in general have wild and crazy magnetic fields.

So if you had to pick, based on all this new info, which planet do you think deserves the award for the weirdest magnetic field?

P.S.: Also, the Cassini mission discovered there’s an electric current flowing between Saturn and its innermost ring.

Lost Opportunity on Mars

~ J.S. Pailly ~ 2 Comments

Over the last few months, a global dust storm has been raging across the surface of Mars.  It started at the end of May and is only now beginning to clear up. It’s been suggested that this was one of the worst storms we’ve ever observed on the Red Planet

The Good News

If you’re worried about the Curiosity rover, don’t be.  The rover’s just kept on roving, and sciencing, and recently it sent back this selfie to let us know everything’s a-okay.

Just kidding.  Here’s a link to the actual “selfie” Curiosity sent back. It’s an interactive 360-degree panoramic thing, so click the image and drag it around to get the full experience.

The Bad News

While Curiosity seems totally unfazed by the bad weather, things are not looking so good for NASA’s other rover, Opportunity.  It’s too early for a eulogy, but based on what it says in this press release from NASA’s Jet Propulsion Laboratory, we should be prepared for the worst.

NASA lost contact with Opportunity in early June, shortly after the storm began.  Unlike Curiosity, which runs on nuclear batteries, Opportunity depends on solar panels for energy.  So the problem may simply be that Opportunity wasn’t getting enough sunlight during the storm.

Or it could be that something more serious has happened to the almost fifteen-year-old rover.  In the press release, Opportunity’s project manager is quoted saying: “If we do not hear back after 45 days, the team will be forced to conclude that the Sun-blocking dust and the Martian cold have conspired to cause some type of fault from which the rover will more than likely not recover.”

So fingers crossed….

Sciency Words: Garn Scale

~ J.S. Pailly ~ 7 Comments

Today’s post is part of a special series here on Planet Pailly called Sciency Words.  Each week, we take a closer look at an interesting science or science-related term to help us expand our scientific vocabularies together. Today’s term is:

THE GARN SCALE

In 1985, Senator Jake Garn of Utah became the first sitting member of Congress to fly in space.  Florida Congressman Bill Nelson followed a year later.  I guess NASA felt it would be good for somebody in Congress to see firsthand how the money for the space shuttle program was being spent.

Senator Garn’s Wikipedia page quotes several astronauts. Apparently not everyone was thrilled about Garn’s mission, but some of them had nice things to say. Astronaut Charles Bolden, who would later go on to become NASA Administrator, said:

Jake Garn was the ideal candidate to do it, because he was a veteran Navy combat pilot who had more flight time than anybody in the Astronaut Office.

And Charles Walker, one of the astronauts who flew with Senator Garn, had this to say:

[…] I think the U.S. space program, NASA, has benefited a lot from both his experience and his firsthand relation of NASA and the program back on Capitol Hill. As a firsthand participant in the program, he brought tremendous credibility back to Capitol Hill, and that’s helped a lot.

Jake Garn may have had a lot of piloting experience before his mission, and afterwards he may have had a lot of positive things to tell his colleagues in Congress, but the mission itself… well, let’s just say weightlessness did not agree with the senator’s stomach.

As a result, Garn’s name has become something of a slang term at NASA.  The Garn scale is an informal, off-the-cuff system to quantify how space sick someone becomes while in space.  Apparently it’s not unusual, even for the most experienced astronauts, to get a little space sick.

A zero on the Garn scale represents not getting space sick at all.  If you do get sick, you’ll probably score a tenth of a Garn, or a quarter of a Garn—some fractional amount of a Garn.  It’s said that no one has ever reached one full Garn’s worth of space sickness, except of course, Senator Garn himself.

Hopefully the senator has a sense of humor about all this.

Hobbit Holes of Mercury

~ J.S. Pailly ~ 2 Comments

Scientists need artists.  This is especially true for those scientists who study the planet Mercury.  According to a convention established by the International Astronomy Union, craters on Mercury are to be named after famous artists, writers, and musicians. And it just so happens that Mercury is the most heavily cratered object in the entire Solar System.

So yeah… Mercury scientists need artists. Lots and lots of artists.

This brings me to one of my all time favorite facts: there’s a crater on Mercury named in honor of J.R.R. Tolkien. And it’s not just any boring old crater, at least not from the perspective of colonists who might one day be living on the first planet of the Solar System.

The best real estate on Mercury is near the planet’s north pole. Sheets of water ice have been detected in that region, within the permanently shadowed bowls of craters where the sunlight can’t reach them.  We recently learned there are similar ice sheets on the Moon, within craters near the Moon’s south pole.

Whether humans go to Mercury in pursuit of natural resources or for the purposes of scientific research, we’ll want to set up shop somewhere with easy access to water. Prokofiev crater (named after a Russian Soviet-era musician) is the deepest of Mercury’s polar craters, and thus likely the iciest.  But Tolkien crater appears to be pretty icy too.

We’ll also probably want to construct our habitats underground.  Underground habitats would provide us with some protection from solar and cosmic radiation, among other things.  Therefore I have to assume that in the distant future, the residents of Tolkien crater will refer to their underground dwellings as “Hobbit holes.”

Sciency Words: Space Adaptation Syndrome

~ J.S. Pailly ~ 5 Comments

While doing my recent research on hypogravity and its effects on the human body, I’ve seen the term space adaptation syndrome come up a few times. I figured it would make a good Sciency Words post. Then I discovered, to my surprise, that I’d already done this one!

So today I’d like to present to you, apparently for the second time:

SPACE ADAPTATION SYNDROME

Yeah, we could just call it “space sickness,” but this is Sciency Words, so we have to call it “space adaptation syndrome.” Because NASA has a rule that all space related terms must be turned into acronyms, we can also call it “S.A.S.”

Most astronauts experience space adaptation syndrome at some point, usually during training or during their first few days in space. Relapses are also known to happen. As you can imagine, NASA really wants to figure out what causes S.A.S. and how to prevent it. This is one of the reasons they recently left an astronaut in space for almost a full year.

Mr11 Year in Space
This is totally how the year in space mission happened.

At present, S.A.S. seems to be similar to motion sickness. It is also sort of the exact opposite of motion sickness. Think of it this way:

  • Motion sickness: your inner ear senses motion, but your eyes do not (because you’re playing with your phone in a moving car, for example). In this case, your eyes are feeding your brain false information.
  • Space adaptation syndrome: your eyes see that you’re moving (or not moving), but in the absence of gravity, your inner ear hasn’t got a clue what’s going on. So in this case, your eyes are trustworthy; it’s your inner ear feeding false information to your brain.

The good news is that we humans can adapt. Our brains learn to rely less on our inner ears, allowing the business of human space exploration to continue.

The bad news is that once we humans adapt to space, returning to Earth becomes a problem. I’m not talking about bone loss or muscle atrophy. I’m talking about balance. All of a sudden, your inner ear is working again, and your brain has to relearn how to do this balancing and walking stuff.

There is also a concern—and I’m not sure how seriously to take this concern—that the human body might adapt too well to space. You might spend so much time up there, becoming so acclimated to zero-G, that your brain and inner ear will never function properly together again. You’ll never walk again. You’ll never be able to come home. You’ll be stuck in space for the rest of your life.

That would suck.

Or maybe it wouldn’t. To be honest, if I ever get to go to space, I probably won’t want to come back anyway.

P.S.: Here’s a bonus Sciency Word: lead-head. Lead-head is what astronauts call immunity from space adaptation syndrome.

How to Walk in Hypogravity

~ J.S. Pailly ~ 8 Comments

As a science fiction writer, I really wish I knew what it’s like to walk on the Moon or Mars or any other low gravity world.  It would help a lot with that whole “writing from lived experience” thing.  Of course there are ways I could experience hypogravity for myself, but I don’t have that kind of money.  So instead, I’ve turned to medical research papers like this one from Frontiers in Physiology.

First off, let me just say this: I’ve read some really complicated stuff over the years, but I don’t think I’ve ever read anything as complicated as a scientific paper trying to describe how we humans walk.

But if we want to understand what it would really be like to walk on another planet, we have to start by understanding—in meticulous mathematical detail, apparently—how we do this walking thing here on Earth.

Gravity Makes Walking So Much Easier

The mathematical relationship between walking speed, leg length, and gravity was determined back in the 1870’s.  It was later used in what sounds like a rather whimsical research paper about the walking pace of the Lilliputians from Gulliver’s Travels.  And then it was used for more pragmatic purposes to estimate the running speeds of dinosaurs.

For those sorts of calculations, the force of gravity would have been treated as a constant, but gravity can easily be treated like a variable, and that’s when things get interesting.  You see, when you walk, your body uses energy to complete the full arc of a footstep, especially at the beginning when you’re lifting your foot off the ground.  But gravity helps you (perhaps more than you realize) when your foot comes back down to the ground.

So if you reduce the force of gravity, gravity provides you with less assistance, and you end up having to expend more energy to complete each step in your walk cycle.

Walking-Mode vs. Running-Mode

The muscle actions involved in walking and running are different enough that there’s no real grey area between “walking-mode” and “running-mode,” as that paper from Frontiers in Physiology calls them. These two “modes of locomotion” take advantage of gravity in distinctly different ways.  Walking-mode ends up being more metabolically efficient at slower speeds, and running-mode is the more metabolically efficient way to travel at higher speeds.

So what happens when you alter the force of gravity?  The transition point where running-mode becomes more efficient than walking-more changes too. Lower gravity means your body will naturally want to switch modes at a lower speed.

On the Moon, for example, walking-mode only works well when you’re moving very slowly.  To achieve what we might consider a normal walking pace, you’ll have to switch to running-mode.  And if you want to reach Earth-like running speed, you’ll probably have to try hopping-mode or jumping-mode—modes of locomotion that we don’t use often here on Earth except under certain specialized circumstances. Skipping-mode also seems to be more metabolically efficient on the Moon than it is on Earth.

Moon-Walking or Mars-Walking in Science Fiction

I’ve read plenty of Sci-Fi stories set on the Moon or Mars. For the most part, I feel like science fiction writers just mention the reduced gravity thing in passing and then move on with the story as quickly as possibly.  I don’t blame them.  It’s really hard to imagine what hypogravity must feel like, and even harder to communicate that feeling to readers.

But one of my highest ambitions as a writer is to write something that makes you feel like you’re there on the surface of a hypogravity planet like Mars.  I want to capture that experience of “running in order to walk” and “hopping in order to run.”  Hopefully this line of research will someday help me pull that off.

Book Recommendation: Chasing New Horizons

~ J.S. Pailly ~ Leave a comment

If you’re a Pluto fan, this book is required reading.  Authors Alan Stern (who led the New Horizons Mission) and David Grinspoon tell us the story of why NASA neglected to send a space probe to Pluto for so long, and how an intrepid group of scientists fought for a Pluto mission and eventually won the day.

This is not just another book about science and technology.  Yes, a large portion of the book is about the technology it took to get to Pluto and the science we learned once the New Horizons space probe started sending back its data. But more importantly this is a David and Goliath story, with NASA’s bureaucracy cast in the roll of Goliath and the so-called “Pluto Underground” playing the roll of David.

I feel like the authors must have made a few enemies at NASA, and maybe a few enemies in Washington D.C. as well, for writing this book. This is an honest and forthright look at the kind of political and bureaucratic resistance New Horizons had to deal with.  As a space enthusiast, I keep hearing about other space missions that are struggling to get to the launch pad.  After reading Chasing New Horizons, I think I have a clearer idea of what causes these sorts of hold up.

And then there’s the elephant in the room: Pluto’s planet status.  The authors say very little about that, which in and of itself says a lot.

I’m guessing the authors made a few enemies at the International Astronomy Union as well.  They give us only a few pages about the I.A.U. vote to demote Pluto and why they believe that vote was wrong.

Overall, I highly recommend this book.  Five out of five stars, or maybe I should give it a rating of nine out of nine planets.

Things I Don’t Understand: Mercury’s Wandering Sun

~ J.S. Pailly ~ 16 Comments

Okay, this is a thing I’ve read about multiple times, but no matter how many times it’s been explained to me I just don’t get it.  Apparently on Mercury, the sun sometimes appears to change directions in the sky.

Let me explain what I mean.  Imagine you’re standing on the surface of Mercury (and are somehow still alive).  You see the sun rise in the east, just as it does on most planets in the Solar System.  And then over the course of a long (very, very long) Mercurian day, you watch the sun slowly (so very, very slowly) travel from east to west.

But at one point, let’s say around midday, the sun appears to stop its east-to-west motion and then, for a short while (about 4 Earth days), it wanders from west to east instead.  Then the sun stops again and continues on its original westerly path.

Why does this happen?  I know it has something to do with the length of Mercury’s solar day versus its sidereal day.  A solar day on Mercury, the time it takes for Mercury to complete a rotation relative to the Sun, is approximately 176 Earth days long. But Mercury’s sidereal day, the time it takes for Mercury to complete a rotation relative to the ecliptic, equals about 59 Earth days.  Also, Mercury’s year is 88 Earth days long, so Mercury’s solar day is roughly twice as long as its year.

Obviously this all means the sun moves very slowly through Mercury’s sky, but why should it briefly stop, turn around, and go the other way?  I just don’t get it. I guess I just can’t conceptualize why this happens.  Maybe if I were better at math, all those numbers would add up for me, and I’d understand what’s going on.

Anyway, does this make sense to anyone else, or are you just as baffled by this as I am?

Update: Looks like I have a lot of really smart readers! It’s still kind of hard for me to conceptualize why this happens, but it’s starting to make a little more sense to me. The first comment from TureNorthBricks definitely cleared up a lot for me.

The Big Martian Maybe

~ J.S. Pailly ~ 4 Comments

Could life exist on Mars?  There’s plenty of compelling evidence that it could, and also plenty of compelling evidence that it could not.  As a result, we’re left with a big, fat maybe. Perhaps the biggest, most frustrating maybe in all of modern science.

After last month’s announcement that the Curiosity rover had found large, complicated organic chemicals on Mars, I was initially tempted to add another point to the “yes, life could exist on Mars” column. But then I read the actual research (which is excellent, by the way).  At this point, I think the only thing we can say for certain is that the big maybe about Mars is even bigger and even more maybe-like.

The Curiosity rover dug up some samples from Martian mudstone, samples that apparently contained organic macromolecules.  What are macromolecules?  For now let’s just say they’re very big molecules.  We can dive into the technical details of what defines a macromolecule in Friday’s episode of Sciency Words.

The problem, as I understand it from that research paper, is that these macromolecules were too big for Curiosity’s instruments to analyze.  So Curiosity destroyed the molecules through a process called pyrolysis (also coming soon to Sciency Words) and analyzed the bits and pieces as they broke apart.  Even those bits and pieces were difficult for Curiosity to study because there were so many of them, but for the most part they seemed to be aromatic compounds made of carbon, hydrogen, and sulfur.

These are the kinds of organic materials that could be deposited on a planet by meteor impacts.  They could also have formed through rather ordinary geological processes.  Or they could be the residue left behind by some kind of biological activity.  And there doesn’t seem to be any way to know for sure where these organics came from based solely on the data Curiosity was able to collect.

So we’re still left with a big maybe.  However, it was once thought by some that the Martian environment was too harsh to preserve these sorts of molecules at all.  Thanks to Curiosity, we now know Mars can and does preserve its organic macromolecules.

And that means that if Mars has had any sort of biological activity, either in the past or present, the chemical record of that activity should be there for us to find.  A definitive yes or no to our question is possible!  We just have to keep digging.