Sciency Words: Patera

September 23, 2016

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For the last few weeks, we’ve been touring the moons of Jupiter and learning about some of the scientific terms used to describe the weird geological features we’ve found there. Today, we conclude this Jovian moons series with the term:

PATERA

Meet Io, Jupiter’s fifth moon and the inner-most of the Galilean moons. Io, say hello to the nice blog readers.

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Oh jeez. I’m sorry you had to see that. Io is sort of caught in a gravitational tug of war between Jupiter and the other Galilean moons. You’d feel queasy too if you were constantly being yanked back and forth by all that gravity.

The result is that Io is the most volcanically active object in the Solar System. Just about any time you look at Io, its sulfur volcanoes are erupting.

A Caldera by Any Other Name…

Astronomers use the word patera (plural, paterae) when discussing Io’s volcanoes. The term comes from the Latin word for flat dish, and the name is appropriate.

Paterae don’t look much like the kind of volcanoes we typically imagine. They aren’t raised, mountain-like features but rather flattened, crater-like depressions. If you know what a caldera is, a patera is basically the same thing.

How Calderas… I Mean, Paterae… Form

Picture this: somewhere on Io, we find an underground chamber full of a nasty, sulfur-rich brew. The temperature in this chamber rises, and the pressure builds up. Suddenly, an eruption occurs, and Io spews that sulfur mixture all over its surface.

As that subterranean chamber empties, the ground above it starts to sink. The resulting pit-like surface feature is a patera. Or a caldera. They really are the exact same thing. (Here’s a short video demonstrating the caldera/patera formation process).

Paterae are not unique to Io. They’ve also been observed on Mars, Venus, and Titan, among other places. They’re also found on Earth, except you’re not supposed to call it a patera if it’s on Earth.

Patera vs. Caldera: What’s the Difference?

If you really want to, you can use the word caldera when referring to Io’s volcanoes, or similar volcanoes on other worlds. That usage seems to be acceptable. But it is unlikely that you will ever see the word patera used for such features here on Earth.

I think there’s a bit of geocentrism at work here. A lot of planetary features have one name on Earth and some other name everywhere else. You’ll sometimes find Earthly terminology used off-world, because Earth terms are more familiar to the average reader; the reverse is rarely if ever true.

Which is fine. I’m not judging. A little linguistic geocentrism makes sense to me, at least at present. In some distant Sci-Fi future where humanity has spread across the Solar System and beyond… at that point, things like the caldera/patera distinction might seem a bit silly.


Taking Things Easy

September 21, 2016

Typically, I like to write three blog posts per week, but I think I’m going to be taking things easy for a while. I’m not stopping or taking a break or anything. It’s just that I’m not doing much serious research at the moment, so I don’t have a whole lot of material to blog about.

There are a few topics I’m interested in covering in the near future, such as:

  • A Trip to Pluto: Maybe something in a similar vein to my recent trip to Titan.
  • The Alien Mega-structure: I’ve been reading up on this “discovery.” If you can get past the hype, there seems to be some genuine science going on.
  • A Tour of the Exoplanets: Not all of them; that would be crazy. I just want to visit a select few.

But that stuff will have to wait, because right now I’m diving into some heavy revisions for Tomorrow News Network. I’m basically rebuilding the T.N.N. universe from the ground up: reinventing physics, religion, and the whole future of human civilization. You know, the kind of stuff every humble science fiction writer does.

I’m also making Talie a little more Talie-like, and her cyborg cameraman a smidge less cyborg-y. These revisions are taking me in some unanticipated directions. I feel like it’s the best writing of my life, and I’m excited for the day when I can put it out there for people to read.

Okay, so that’s what I’m up to right now. That’s what I mean when I say I’m “taking things easy for a while.”


Sciency Words: Facula

September 16, 2016

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When Voyager 1 trained its camera on the moons of Jupiter, scientists back on Earth had no idea what to expect. Turned out they were right. Voyager was snapping photos of geological features unlike anything anyone had ever seen before. Which meant it was time to make up some new sciency words!

FACULA

Last week, we learned about the word macula (plural, maculae): a special term for dark spots on the surface of a moon or other planetary body. Now if you’re going to invent a special term for dark spots, you really ought to have a term for bright spots too. And that term is facula (plural, faculae).

To an ancient Roman, facula meant “little torch.” To a modern planetary scientist, it refers to a surface feature that looks brighter than the surrounding terrain. The term was first used this way to describe bright, circular features seen on Ganymede.

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If you think Ganymede’s faculae look a little like craters, you’d be on the right track. Like most moons in the outer Solar System, Ganymede is composed of a mixture of rock and ice, and it may have a layer of liquid water beneath its surface.

So the craters left by asteroid impacts on Ganymede sometimes get filled in with icy slush. The slush freezes, and the crater is virtually erased. Only the crater rim remains, and you can see a color difference between old and new surface ice.

The term facula can be used to describe almost any bright spot on a planet-like surface, not just resurfaced craters. For example, there are faculae on the dwarf planet Ceres. Ceres’s faculae are still being investigated by the Dawn spacecraft, but the current best guess is that they’re salt deposits—perhaps salt left behind after very briny water boiled into space.

For next week’s edition of Sciency Words, we’ll conclude our visit to the moons of Jupiter with a quick trip to Io.

Bonus Sciency Word: An impact crater that gets filled in and smoothed over, like the craters on Ganymede, is also called a palimpsest.


SETI Hoopla

September 14, 2016

SETI discovered aliens! They detected a transmission from an advanced alien civilization located 94 light-years away! I saw it on T.V., so it must be true.

Okay, I actually wasn’t planning to say anything about this. It’s just another case of bad journalism and the misreporting of science. But this story seems to have developed legs—or maybe tentacles—and it just keeping popping up in my newsfeed.

When the story initially broke, I quickly checked SETI’s website. To my amusement, I found nothing: no press release, no mention of an alien signal at all. My thought at the time: where on Earth (pun intended) did the popular press get this story from?

There are others far more qualified than I to get into the nitty-gritty of what happened, or rather what didn’t happen, with this alleged SETI signal. I recommend this post from cosmicdairy.org. From what I gather from everything I’ve read, the basic summary is this:

  • In May of 2015, Russia’s RATAN-600 radio telescope detected “something.”
  • The signal was quickly determined to be a false positive. Apparently this happens a lot with all the radio noise from Earth and satellites in Earth orbit.
  • The story should have ended there.

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Weather Report from Jupiter

September 12, 2016

Juno has completed its second flyby of Jupiter, skimming close to the atmosphere and managing to get some interesting pictures of Jupiter’s polar regions.

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Apparently we’ve never gotten a good look at Jupiter’s poles before. I imagine there’s a lot of frantic technical analysis going on right now at NASA, but not a whole lot of info has been released to the public so far.

We do have a press release, which I’m taking as a small preview of the real science that’s still to come. From the press release, we’ve learned that:

  • There’s a heck of a lot of storms, sort of clustered together. It’ll be interesting to find out which way they rotate. Are we looking at cyclones or anticyclones? (The Great Red Spot is an anticyclone, by the way).
  • Apparently cast-shadows are visible, suggesting clouds of varying altitudes. I’m guessing we’ll learn something about regional temperature and pressure variations from that.
  • The clouds have a bluish tint. In my inexpert opinion, that might indicate elevated concentrations of methane (the gas that makes Uranus and Neptune look so blue). That would be a change from the ammonia clouds we’re used to seeing in Jupiter’s upper atmosphere.

In short, it sounds like Jupiter’s polar regions have a whole separate ecosystem of clouds and storms. Do these storm systems function independently from the belts and zones observed at other longitudes, or could there be some complex relationship at work?

The Juno spacecraft has a little less than two years to find out. Good luck, Juno. We’re all counting on you.


Sciency Words: Macula

September 9, 2016

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When Voyager 1 trained its camera on the moons of Jupiter, scientists back on Earth had no idea what to expect. Turned out they were right. Voyager was snapping photos of geological features unlike anything anyone had ever seen before. Which meant it was time to make up some new sciency words!

MACULA

Last week, we talked about Europa’s lineae: the reddish-brown cracks and fissures crisscrossing this small moon’s surface. But those weren’t the only surprises Voyager 1 observed. Let’s zoom in for a closer look.

Sp09 Macula on Europa

Europa has these peculiar dark splotches on its surface, similar in coloration to the lineae. Scientists came up with the term macula (plural maculae) to describe them. It comes from the Latin word for “spot” or “blemish.” It’s related indirectly to the word immaculate, which literally means “without blemish.”

Although Europa’s maculae were discovered in 1979, it wasn’t until 2011 that anyone could adequately explain them. It seems that Europa’s thick ice shell has a complex relationship with the ocean of liquid water deep beneath the surface, resulting in frequent patterns of melting and refreezing.

Sometimes “lakes” of liquid water become embedded between layers of ice. This causes surface ice to sag and cave in, breaking up into chunky, tightly packed icebergs. Some sort of material (possibly organic material) seeps up with the meltwater, causing the dark discoloration.

Eventually, the lake beneath a macula will freeze. Since ice is less dense than water, this forces the now cracked and broken surface ice to rise above the surrounding landscape. In the process, the already strange-looking maculae transform into even stranger-looking chaos terrain.

The term macula can be used to describe almost any dark, spotty or splotchy feature on a planetary body. That doesn’t mean they have anything in common beyond superficial appearances. For example, while maculae on Europa seem to be caused by melting and refreezing ice, maculae on Titan may be related to some sort of volcanic activity.

For next week’s edition of Sciency Words, we’ll move on to Ganymede. Europa wasn’t the only Jovian moon showing off strange, never-before-seen geological features when Voyager arrived.


IWSG: A Muse’s Apprentice

September 7, 2016

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We all know writers feel insecure sometimes. That’s what the Insecure Writer’s Support Group is all about. What we writers might not realize, or may sometimes forget, is that our muses get insecure too.

With that in mind, I’m going to turn the floor over to my muse. She has something to say, and maybe it’s something you or your muse would like to hear.

* * *

We all know the rule: one muse per writer. There just aren’t enough of us fairy-folk around to start doubling up. But I wish I could have a helper or an assistant or something. I wish I had an apprentice muse working under me. Then I could really get stuff done.

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The truth is I can’t do everything myself. I can put as many ideas into my writer’s head as I want, but that doesn’t mean he’ll write them down. You know how humans are. They’re easily distracted. Their minds wander. They keep complaining about being “too tired.”

It would be nice if I could get some help. Unfortunately, King Oberon and Queen Titania have rejected my requests to start a muse internship program. That leaves me only one option: I’ll have to convince my writer to pull his own weight. Well, that plus the weight of a pen, I guess.

That way, when I give my writer ideas, he’ll be able to move his own hand over to the paper, without any magical help at all.