Planet Pailly

Sciency Words: Tentacle

July 21, 2017

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:

TENTACLE

Believe it or not, octopuses do not have any tentacles. Zero. None. They have four pairs of arms, according to cephalopod experts.

When discussing cephalopod anatomy, arms are defined as shorter, more muscular appendages with suckers all the way along their length. Tentacles are longer and only have suckers at the “club-shaped” end. So octopuses have eight arms. Squid and cuttlefish have eight arms and two tentacles.

As a science fiction writer, I’ve created a few characters who have tentacles. Or at least, I think I have. But maybe my buddy Omglom here only has arms.

However, after doing further research I’ve found that this arms vs. tentacles thing is specific only to cephalopods. In a more generalized zoological sense, just about any boneless, flexible, elongated appendage can be referred to as a tentacle.

The word tentacle traces back to a Latin word meaning “to feel” or “to test” or “to probe.” This seems appropriate to me because in most cases tentacles aren’t really for grasping or manipulating objects. They’re sensory organs used for feeling, smelling, tasting, and even seeing (for example, the eyestalks of slugs and snails are considered to be tentacles).

There’s even a mammal with tentacles: the star-nosed mole, which has twenty-two tiny tentacles arranged in a star pattern around its snout. These tentacles are extremely sensitive feelers which help the star-nosed mole feel its way around as it burrows through the earth.

As for my friend Omglom… the gelatinoids of Rog aren’t cephalopods, so his tentacles can be called tentacles after all!

P.S.: It may sound strange, but the proper plural form of octopus is octopuses, not octopi. The cephalopod expert at the end of this video does an outstanding job explaining why.

4 Comments | Uncategorized | Permalink
Posted by J.S. Pailly

NASA’s Next Flagship Mission

July 19, 2017

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?

15 Comments | Enceladus, Europa, Mars, Neptune, Space, Titan, Uranus, Venus | Permalink
Posted by J.S. Pailly

Going Up: Jupiter’s Auroras Get Weirder Than Ever

July 17, 2017

Last week, the Juno mission flew over Jupiter’s Great Red Spot and sent back some spectacular close-ups. But I’m not ready to talk about that. Not yet. I’m still catching up on the Juno news from two months ago.

Toward the end of May, NASA released a ton of fresh data from Juno, including new information about Jupiter’s auroras. Astro-scientists had previously known about two sources contributing to these auroras: the solar wind and the Io plasma torus. Now Juno may have discovered a third.

As Juno flew over Jupiter’s poles, it detected electrically charged particles flying up.

I can’t emphasize enough how weird this is. I wanted to write about it right away, but I held off doing this post because I was sure I must have misunderstood what I was reading.

Auroras are caused by electrically charged particles accelerated down toward a planet’s magnetic poles. These particles ram into the atmosphere at high speed, causing atmospheric gases to luminesce. At least that’s how it’s supposed to work. I guess nobody told Jupiter that.

In addition to the “normal” downward flow of particles from the Sun and Io, Jupiter’s magnetic field apparently dredges charged particles up from the planet’s interior and hurls them out into space. So Jupiter’s auroras are triggered by a mix of incoming and outgoing particles.

This definitely falls under the category of “further research is required.” Even now, I still feel like I must have misunderstood something. This is just too weird and too awesome to be true.

P.S.: As for the Great Red Spot, I’m waiting to hear something about the microwave data. We’re going to find out—finally!—just how far down that storm goes.

3 Comments | Jupiter, Space | Permalink
Posted by J.S. Pailly

Sciency Words: Airglow

July 14, 2017

AIRGLOW

Have you ever been floating in space, looked down at the Earth, and noticed a faint halo of green light around the planet? Me neither, but that light is there and it’s called airglow. Why’s it called that?

This is Anders Angstrom, a 19^th Century Sweedish research and one of the founders of the science of spectroscopy. He’s the guy who, in 1868, first observed the airglow phenomenon.

As often happens in science, this was a serendipitous discovery. Angstrom was trying to study one thing when he accidentally discovered something else. He was using a spectroscope to measure the emission lines of the aurora borealis—or to put that in plain English, he was trying to find out precisely which colors make up the Northern Lights.

To Angstrom’s surprise, one of the aurora colors—a narrow band of green—was always present in the sky even when the aurora wasn’t happening. Angstrom couldn’t explain this, but over the coming decades other researchers would continue investigating this faint green glow, ruling out one possibility after another: it couldn’t be starlight, or moonlight, or light pollution….

Eventually scientists settled on an explanation involving chemistry. We now know that chemical reactions in the atmosphere release energy in the form of photons. The most noticeable reactions involve oxygen reacting with itself, producing photons of a specific wavelength, a wavelength corresponding to a narrow band of green light.

We’ve also observed airglow on other planets. The different colors we see on Venus, Jupiter, or Saturn can tell us a lot about the chemicals in those planet’s atmospheres. And some day a faint green emission line from an exoplanet may lead us to the discovery of alien life.

Image courtesy of NASA.

I opened this post from a vantage point in space, because as I understand it Earth’s airglow is a lot easier to see from up there. But it can be seen from down here on the ground too if you have sharp eyes, a good camera (or a good spectroscope), and know what to look for. Click here to learn more.

Leave a Comment » | Earth, Sciency Words, Space | Permalink
Posted by J.S. Pailly

Io: Jupiter’s Ugliest Moon

July 11, 2017

For today’s post, I hopped in my imaginary spaceship and flew all the way out to Io, one of Jupiter’s moons. Without a doubt, Io is the ugliest object in the Solar System.

I know, that’s mean. I shouldn’t say things like that. But come on, just look at it. Seriously, look at it. It’s like some moldy horror you might find in the back of the fridge.

So yeah, Io’s hideous. Let’s go look at something else instead. Something pretty, like Jupiter’s auroras.

We have auroras back on Earth, of course, but Jupiter’s are a whole lot bigger, a whole lot more powerful, and when viewed in ultraviolet, a whole lot brighter. Also, unlike Earth’s auroral lights which come and go, Jupiter’s are always there. They may vary in intensity, but they never stop, never go away.

Auroras are caused by charged particles getting caught in a planet’s magnetic field, directed toward the magnetic poles, and colliding at high speed with molecules in the planet’s atmosphere.

On Earth, those charged particles come mostly from the Sun in the form of solar wind. No doubt the solar wind contributes to Jupiter’s auroras as well, but the greater contributing factor is actually—believe it or not—Io. That’s right: ugly, little Io causes Jupiter’s auroras. I guess spreading ionized sulfur all over the place is good for something after all!

In fact if you ever get to see a Jovian aurora, you’ll notice little knots in the dancing ribbons of light. These knots correspond to the positions of several of Jupiter’s moons. And the largest, brightest, most impressive of these knots… that one belongs to Io.

Image courtesy of Wikipedia.

So I guess today’s lesson is that even the ugliest object in the Solar System can still help make the universe a more beautiful place.

7 Comments | Io, Jupiter, Space | Permalink
Posted by J.S. Pailly

Sciency Words: Plasma Torus

July 7, 2017

PLASMA TORUS

Saturn may have the most beautiful rings in the Solar System, but Jupiter’s got the most impressive plasma torus. Torus is the proper mathematical term for a donut shape, and plasma refers to ionized gas. Put the two words together and you get a giant, donut-shaped radiation death zone wrapped around a planet’s equator.

Jupiter’s plasma torus is faint, almost invisible; but if we take the totally legit Hubble image below and enhance the sulfur emission spectra, you’ll see what we’re talking about.

Ever since the discovery of Jupiter’s decametric radio emissions, astronomers have known there must be a relationship between Jupiter’s magnetic field and its moons. Well, I say moons plural, but it’s really only one moon we’re talking about: Io.

It wasn’t until the Voyager mission that we figured out why Io has so much influence over Jupiter’s magnetic field. In 1979, the Voyager space probes discovered active sulfur volcanoes on Io. They also detected ionized sulfur and oxygen swirling through space conspicuously near Io’s orbital path.

It seems that due to Io’s low surface gravity, Io’s volcanoes can easily spew a noxious mix of sulfur dioxide and other sulfur compounds up into space. Jupiter’s intense and rapidly rotating magnetic field acts as a sort of naturally occurring cyclotron, bombarding these sulfur compounds with radiation, breaking them apart into ionized (electrically charged) particles and accelerating those particles round and round the planet.

The result is a giant, spinning, donut-shaped cloud of ionized gas. We’re talking about a lot of radiation here—seriously, keep your distance from the Io plasma torus! We’re also talking about a lot of electrically charged, magnetically accelerated particles moving through a planetary magnetic field.

One source I read for today’s post described Io as “the insignificant-looking tail that wags the biggest dog in the neighborhood.” Jupiter has by far the largest, strongest magnetic field of any planet in the Solar System, but thanks to this plasma torus, it’s Io—tiny, little Io—that has the real power in the Jovian system.

Next week, we’ll go take a look at Jupiter’s auroras. They’re rather different from the auroras we have here on Earth, and SPOILER ALERT: Io has a lot of control over them.

7 Comments | Io, Jupiter, Sciency Words, Space | Permalink
Posted by J.S. Pailly