Tag: Voyager 2

Moons Gone Wild: Naiad and Thalassa

~ J.S. Pailly ~ 9 Comments

Naiad is one of the more rambunctious and troublesome moons in our Solar System.  She was first discovered in 1989 when NASA’s Voyager 2 spacecraft flew by Neptune.  Naiad then spent more than a decade playing hide and seek with us, to the annoyance of many professional astronomers, I’m sure.

In 2004, the Hubble Space Telescope happened to catch Naiad in a few images of Neptune, but no one noticed she was there.  It wasn’t until 2013, thanks to new and improved image processing techniques, that astronomers found Naiad in those pictures.

Articles from the time (like this one or this one) described Naiad’s orbit as “wibbly wobbly” or said Naiad had somehow “drifted off course.”  That’s why we’d had such a hard time finding her.

But new research published this month in the journal Icarus gives us a clearer sense of what Naiad’s been up to all this time.  Naiad’s orbit is just… I don’t know how to describe it.  Just look at this orbit!  It’s bizarre!

According to that paper in Icarus, Naiad is caught in an orbital resonance with the neighboring moon of Thalassa.  That orbital resonance, combined with a high inclination (orbital tilt), causes Naiad to travel in a “sinusoidal pattern,” as the authors of that paper call it.

Naiad and Thalassa orbit dangerously close to each other.  Naiad zips past Thalassa every seven hours, approximately.  But because of that weird sinusoidal thing Naiad’s doing, Naiad always passes safely over Thalassa’s north pole or safely under Thalassa’s south pole.  The two moons are in no danger of getting into any sort of accident with each other, at least not in the near future.

But there are still a lot of uncertainties baked into our models of Neptune and his family of moons.  Even our newest, most up-to-date model—the model that revealed Naiad’s orbital resonance with Thalassa—still depends heavily on data collected by Voyager 2.  And as the authors of that Icarus paper note: “The orbital uncertainties show that the positions of the satellites are known within several hundred kilometers until at least 2030.”

But beyond 2030?  I guess we can’t accurately predict where Naiad, Thalassa, or any of Neptune’s other moons might end up.  If only somebody would send another space probe out to Neptune!  I’m really glad we have Voyager 2’s data, of course, but that data is from 1989.  A follow up mission is long overdue!

Meet Ariel, a Moon of Uranus

~ J.S. Pailly ~ 3 Comments

I have a friend who’s obsessed with The Little Mermaid.  So if I’m going to write a post about Ariel, one of the moons of Uranus, it would be a real shame if I couldn’t make some sort of Little Mermaid reference.

Unfortunately, we know precious little about Ariel, or any of Uranus’s moons, for that matter.  Only one spacecraft has ever visited: NASA’s Voyager 2, way back in 1986. And the data Voyager 2 sent back gives us a frustratingly incomplete picture.

What I can tell you is that Ariel’s surface is made of ice, specifically water ice and carbon dioxide ice.  One hemisphere appears to have more carbon dioxide than the other, according to this paper from Icarus.  And according to this profile piece from NASA, Ariel is the shiniest of Uranus’s moons–it reflects more sunlight than the others.  Oh, and Ariel’s surface appears to be younger than the surfaces of those other moons as well.  That might be important!

In fact, according to this article from Scientific American:

[The Voyagers 2] flyby revealed Ariel to be relatively smooth, as if its surface was being continually renewed by activity deep within.  It is currently believed to be the only ocean world in the Uranian system.

A word of caution: that Scientific American article says a lot of highly speculative, highly conjectural stuff. Take it with a grain of sodium chloride.

However, in the absence of better, more detailed information about Uranus and its moons, it sounds like Ariel could maybe possibly be Uranus’s version of Europa or Enceladus.  It could possibly be a moon with an icy crust floating atop an ocean of liquid water.  It might even be the kind of environment that could support life.  There might even be….

But no, I shouldn’t make a claim like that.  It would be irresponsible of me as a science blogger.  Voyager 2’s data was too limited, and subsequent observations by Hubble or other Earth-based telescopes can only tell us so much.  Until our next mission to Uranus (whenever that might be), we really can’t say what might be hiding beneath the icy crust of Ariel.

#IWSG: Being a Writer is Soooo Boring!

~ J.S. Pailly ~ 31 Comments

Welcome to the Insecure Writer’s Support Group!  If you’re a writer, and if you feel in any way insecure about your writing life, click here to learn more about this awesome group!

I, J.S. Pailly, stand accused of being a boring person.  Or at least that’s what a few well-meaning friends and acquaintences seem to think.  You see, all I ever do is write and read and do research.  Then I do more research, which is followed up with more writing.

Most people are willing to concede that all the art I do might be fun.  But otherwise my life is soooo boring.  Boring, boring, boring.  I need to get out more, travel, go to loud parties, eat at popular restaurants… or other stuff like that, I guess.

Anyway, I’ve been accused of being boring.  So in my defense, I’m going to talk about something that I find really interesting: space.  And perhaps the story I’m about to tell will serve as a nice little allegory about what it means to be boring or interesting.

In 1986, the Voyager 2 spacecraft became the first—and thus far the only—spacecraft to visit the planet Uranus.  As I’m sure you’re already aware (you may already be giggling), Uranus is a much-maligned planet, because of its name.  Voyager 2’s visit gave us yet another reason to malign our poor seventh planet.

Uranus turned out to be a featureless cyan-blue orb.  There was nothing like Jupiter’s Great Red Spot or Saturn’s polar hexagon.  There were no atmospheric zones or belts.  There was nothing interesting to look at at all! What a boring planet, scientists said.

But of course, this was only true from our limited human perspective.  Our eyes can only see a range of approximately 400 to 700 nanometers on the electromagnetic spectrum (which we perceive as the colors violet to red).

If you observe Uranus only in this 400 to 700 nm range, there’s not much to see.  Switch to ultraviolet, however, and you’ll find a complex and dynamic atmosphere that’s every bit as interesting as Jupiter or Saturn’s.

Whether we’re talking about planets or people, what is boring versus what is interesting is all a matter of perspective.  Will this little anecdote change anybody’s mind?  I’m not sure.  I suspect if you already think I’m a boring person, me talking about sciency stuff only reinforces that belief. But I hope the rest of you get what I’m trying to say.

P.S.: Fun fact!  If you’ve ever wondered why Uranus got stuck with its giggle-inducing name, it’s because the guy who picked the name was German, and he probably didn’t realize what it would sound like in English.