Get Well Soon

Cassini, the hardest working probe in show business, is sick. It went into safe mode last week just before it was to do a close fly-by of Saturn's moon Titan, the second largest moon in the solar system, and the only one with an atmosphere. There are supposed to be lakes of liquid methane down there, and maybe critters as well (the conspiracy buffs on Coast to Coast believe Cassini isn't broken at all, but rather the scapegoat in a massive cover-up).

Not to worry. Cassini has gone into safe mode six times before, and came out fine each time. Plus, 53 other fly-bys of Titan scheduled.

The JPL says, "The spacecraft is very tolerant of error. It'd be hard to break it."

Menwhile, here's a gorgeous picture of Saturn and the rings Cassini took in healthier days, a tumble of light and shadow, spheres and rings. The triangular slab of shadow is the shadow of Saturn itself, so the sun must be off to the lower left, well out of the frame.

Thanks to Bad Astronomy for the pic.

Three Cool Things

My favorite citizen of the solar system, Saturn's moon Enceledus (the moons that switch orbits every four years are a close second and third*).

Three cool things about this picture.

One: that tiny flare of light coming from the bottom of the moon is caused by ice geysers, spewing ice hundreds of miles out into space. Carbon particles have been found in the ice. Water, carbon, and a heat source that causes the geysers. Sounds like Arthur C. Clarke's monolith is at work deep under the ice. It's full of staaaars....

Two: that faint line behind Enceledus is Saturn's E ring, composed almost entirely of ice particles form those crazy geysers, settling into orbit.

Three: look at the pattern of light and shadow on Enceledus. The bright crescent of light on the left, the dark bit, and then another bright section. There are two light sources! The bright crescent on the left is caused by sunlight. The light on the right is Saturnlight, the glow from the planet 150,000 miles away.

Thanks to Cassini, NASA, and Bad Astronomy for the pix and the info.

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*the mysterious clump of particles orbiting Saturn that may or may not be a black hole is a distant fourth.

More Saturnian Weirdness

Curiouser and curiouser.

In this week's headlines: Saturn's moon Prometheus is creating giant snowballs in the wake of it's gravitational field. It pulls the material off the F ring, and the gathered material creates enough gravity on its own to clump together into snowballs, following Prometheus around like ducklings. Prometheus also creates these weird "fans" in the F ring:

More curious still are "mysterious tumbling objects" that go ricocheting back-and-forth across the F ring before vanishing from sight. Sometimes they have comet-like tails, and their orbits can't be tracked. Note that UFO abductees are not reporting this, NASA's Cassini probe is. These things are real. There is such tumbling chaos in Saturn's rings, billions of tiny particles in orbit, pulling and colliding, but from out of this chaos spins rings and moons and ripples and spokes and fans and propellers. So much stunning complexity, born from Kepler's three simple, elegant laws of planetary motion. The idea that these structures form out of the infinite permutations of a few simple laws of physics fills me with more awe, more childlike wonder, than the notion they were created by a God.

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Going to Rockygrass this weekend. Three days of bluegrass and hula hoops and friends and beer and camping and dozing in the hammock and playing in the water. Big Fun. Summer revolves around Rockygrass in the same way winter revolves around Christmas. It lies in the sweet spot, at the center of the season.

News of the Weird

One of the weirder headlines of the week: Giant Propellers Discovered In Saturn's Rings. It's a tad misleading. They don't spin or anything. And as far as I can make out, they aren't even really solid. The center is a brand new class of moon, one that is mid-size and embedded in the rings, and (I think) there is material streaming out thousands of miles in both directions, held in place by gravity and resonance, a concept I must admit I don't entirely understand.

As opposed to gravity, which no one understands. There was an article in the NY Times yesterday about a theory that gravity doesn't even exist, but is rather a byproduct of thermodynamics. I didn't entirely understand that either.

I digress. These space propellers are several miles wide, several thousand miles long. Their orbits are thus far unpredictable; they've been photographed before, but no one is sure when and where one of the Damned Things will turn up next. A picture of one is below. Unlike the propeller, the red arrow is not actually embedded in the rings. That would be weird.



Odd headline #2: Frustrating Zombie Satellite Still Adrift In Space. Apparently it is out of its intended orbit and can't be controlled, but is still sending out signals, and signal interference could kill other satellites. Following the zombie analogy, those satellites it kills would then turn into zombie satellites, causing all sorts of mayhem up there, but I think I may be stretching the analogy too far.

Photo by NASA's ever-fascinating Cassini probe.

Geysers of Enceladus

My favorite moon. 

That's Saturn in the foreground, and the crescent Enceladus behind it.  The remarkable bit about this shot is the erupting geysers clearly visible at the south pole of Enceladus (at the very bottom of the crescent; click the picture to make it bigger).  Wow.  These ice geysers are coming from quarter mile deep cracks in the surface of the ice, called the Tiger Stripes.  The Cassini probe keeps making passes over this section, and on this last pass, on Feb 23, observed 30 geysers.  This was once supposed to be a dead moon, all rock and ice.  Now we know it to be alive with geological activity, and likely hiding a great lake of water beneath all that ice (though the jury is out on that).

Curiouser and curiouser.

Here's a close-up.

 
Thanks to Cassini, and to Bad Astronomy, for the pix.

Dance of the Moons

Worth embiggening. I could watch this stuff all day. And may do just that.

Thanks to Space Gizmo for the link. And Cassini. And the JPL. And NASA.



Merry Christmas.

More Saturnian Weirdness

Something big and weird punched through Saturn's F-ring recently. Here's a picture.



To help you make sense of the image: the thing was approaching from below the ring, blasted through the ring and left a plume of material pointing toward the upper right hand corner of the picture, the plume is casting a shadow toward the lower lefthand corner.

No one knows what it is. Other than a great big space rock, probably.

I learned about it by listening to Phil Platt, of Bad Astronomy, on Coast to Coast last night (I got the pix from his site as well). For those of you not in the know, Coast to Coast is the gloriously strange radio show devoted to alien abductions, the Hollow Earth theory, the Taos Hum, Bigfoot, etc. It's about 80% silly, 20% interesting.

This is from the 20% interesting bit.

It comes on the heels of the comet slamming into Jupiter last month. Do I sense a pattern here? Did some passing object perturb the orbits of all those frozen space rocks at the edge of the Solar System? Are we about to be bombarded with shrapnel from the Oort Cloud?

Stay tuned.

Teenage Wasteland

Those mysterious space blobs are now a little less mysterious. To recap: last month astronomers found powerfully energetic blobs--the scientific paper actually called them "blobs"--at the very edge of observable space, some of most distant objects ever recorded. At the time the leading theory was we we witnessing the violent births of baby galaxies, with baby black holes at their centers.

As it turns out, they are teenagers. They are galaxies going through all sorts of crazy changes before maturing and stabilizing. James Geach, the lead researcher of the study, said that the chaos "is due to the violent processes occurring in the galaxies, black hole growth, starbursts, mergers. They're having a final 'tantrum' before they're done growing and then 'passively' evolve to the present day.

Sound familiar?

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NPR was reporting rather breathlessly last week that Enceladus, the geyser-spouting moon of Saturn, has liquid salt water seas under it's crust. It might be true: Cassini flew through the geysers last year and, according to one set of scientists, found evidence of salt water in the geysers. That is deeply cool, in that salt water oceans were the cradle of complex life on Earth. However, the same issue of Nature has a paper from another team of scientists from Boulder, who say there isn't enough sodium in the samples to support the salt water ocean hypothesis. So the jury is out.

And NPR is a little bit busted.

Fly By

Beautiful picture snapped by Cassini, still orbiting Saturn, still waltzing amid the moons and rings. It does a fly-by of Titan in four and a half hours, according to the Cassini site.

I read recently that NASA uses Titan to make changes in Cassini's orbit. The fly-bys change Cassini's trajectory, and allow NASA to swing it pretty much wherever they want. That's how they got it to fly through the vapor plume on Enceladus last year. Quite cool.

That's Titan in the background, tiny Epimetheus in the foreground.

The picture is from the Astronomy Picture of the Day.

Chaos Beneath the Calm

This pic was discussed on a buncha astronomy blogs a few weeks ago (the Planetary Society Blog has the best discussion). It's a close-up of Saturn's rings. Ignore the big pointy shadow on the right, that's from Mimas, a moon of Saturn. Note instead the jagged shadows along the diagonal of the pic, where one ring is casting shadows on the next ring in. Cool, huh? No one is quite sure what is causing it, though the best guess is there is a lot of variation in size in the particles that make up that specific ring (though, interestingly, not the others). Alternately, it could be a bunch of smaller particles clumping up, due to gravitation. So the rings are not so much flat surfaces as a bunch of tiny moonlets bouncing around, colliding, clinging together for awhile, blasting apart, reforming into new groups. I like the idea of such a seemingly serene structure having all that chaos teeming just beneath the surface. Metaphors abound.

The reason, by the way, the shadows can be seen at all is that the rings are very close to being parallel to the sun's rays (think of trees casting long shadows in late afternoon).

Here's a close-up.

Music of the Rings

You need to trust me and just listen to this.

It's eerie and strange and a little scary and quite literally otherworldly. This is the sound of the radio emissions coming from Saturn, recorded by Cassini, and dubbed "The Music of the Rings" by Donald Gurnett, a physicist at University of Iowa. The video accompanying the audio explains the details, so I won't bother.


I stole this from the always interesting GM=tc^3: A Babe in the Universe. She thinks it's an indication of a black hole in the center of Saturn, and goes on to say planets may be "seeded" by black holes in the early formation of solar systems. Who knows, she might be right; she's certainly smarter than I am.


Here's a closely related picture (also stolen from GM=tc^3) of the aurora around Saturn's North pole (the image was captured by Casinni as well). This is the same phenomenon as the auroras powering the Northern Lights here on Earth. Both are caused by the strong magnetic fields surrounding the two planets. And those same magnetic fields produce radio signals, which in turn produce all that crazy music. They make the worlds sing.

Click it to enlarge it. It'd quite a beautiful picture.

Anthe and Methone

This is a picture of two tiny moons of Saturn - Anthe (top left) and Methone (bottom right) - in Saturn's faint G ring. The moons are only a couple of miles across. Those arcs the moons are sitting in are caused by debris from mirco-meteorites hitting the surface of the moons. The cool thing here is that, after countless orbits around Saturn, the debris should form complete rings, as the material spreads out and around. That's what scientists expected to see. But, as I've said many times here before, the closer you look, the weirder it gets.



Apparently the debris forming the arcs is kept in place by gravitational resonances with other moons of Saturn, a concept I must confess I don't fully understand. It has something to do with a set of moons gravitationally interacting with each other (there is a third one, Pallene, in this "family" of moons). Even weirder, the moons aren't always in the center of their arcs, but wander to one side, then the other.

I like the idea of incomplete structures out there. It's easy to see Saturn's rings as stately and unchanging, proof of a stable, predictable clockwork universe. The arcs point to a more accurate picture of things, a solar system that is forever changing and evolving, rearranging itself into ever more complex structures. The moons and their arcs remind me of scaffolding around a building, the girders of a skyscraper under construction, the first few halting paragraphs of a new chapter in an epic narrative.

The photo is from NASA.

Every Time You're Mean To Your Sister, A Unicorn Cries

The title has nothing to do with the rest of the post, it just popped into my head this weekend and has been stuck there ever since. I didn't say it. Wanted to. But didn't.

No camping trip last weekend, due to heavy rains. And although rain is always welcome here in the high desert, and Saturday was a dream, cabin fever settled in with a vengeance by Sunday afternoon. Thus the crying unicorns.

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I know I've written about it a lot in the past, but I can't help but gush: the Cassini spacecraft is the single coolest thing we've ever flung into space (at least until the New Horizons probe gets to Pluto and the Kuiper Belt and eventually even our good friend The Oort Cloud). The Cassini mission just gets cooler and cooler, weirder and weirder, dipping and diving among the moons and rings and other strange critters orbiting Saturn, changing course every few weeks to check out something new and improbable. It's not a pre-programmed path, but done somewhat on-the-fly; whenever they find something cool they scoot Cassini past it for a closer look. A few months ago Cassini did a spectacular fly-by of Saturn's bizarre ice-spewing moon Enceladus, where it flew through a giant ice geyser to see what it was made of, how hot it was, etc.

Now it's back! Flying at an altitude of 30 miles, going 64,000 miles an hour, Cassini took this shot:

Let me repeat that: 64,000 mph, and skimming only 30 miles above the surface. That's an exacting flight path, particularly when it's being flown by people literally 800 million miles away.

Next pass will be from 15 miles high.

The reason Enceladus is getting so much attention is because of those geysers. They come out of a set of four great cracks in the ice called the Tiger Stripes. Beneath the cracks is some sort of heat source, probably in the form of tidal friction from Saturn (though the Babe in the Universe thinks, predictably, that it may be a black hole). The combination of water, a heat source, and the presence of carbon molecules (discovered in the ice geyser during the last fly-by) have made this number one with a bullet on the short list of places offering the possibility of life in our solar system. Nowhere else have water, a heat source, and carbon molecules been found in the same place. All three are considered prerequisites for life.

This is an exciting time. Ice on Mars. Methane lakes on Titan.

Life here on Earth is tenacious and resilient enough so that we find it in the Arctic, in deserts, in acidic environments, high radiation environments, huddled against underwater volcanic vents. Perhaps it's merely a hedge against my Godless world view, but I'd like to believe life is as plentiful out in space, and as infinitely varied, as it is here on Earth.

We might find out real soon.

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I'd be remiss if I didn't add that Pedro pitched a poem of a game this last Saturday, his best outing of the season. 7 innings pitched, 1 earned run, 8 hits, 1 walk. He's back! And, not coincidently, the Metros are in first place.

The Yankees, meanwhile, with virtually the same record, are 10 games out of first place. Ah, the vicissitudes of baseball.

Cassini

As you might have guessed, I'm a big fan of space exploration. Not manned exploration, which is dangerous and needlessly expensive and yields relatively little actual science, but unmanned exploration, where you fling probes out there to all the coolest spots in the solar system (and beyond!) to see what they look like. Everything in space gets weirder the closer you look at it. And Lord knows I like weird.

The "Golden Age" of unmanned NASA probes is coming to a close, as they retool for President Monkeybone's meaningless manned missions to the moon and Mars. There's a probe currently going out to the Kuiper Belt and the Oort Cloud (ouch!), and I think there's one en route to a comet. And there is, of course, the uber-cool Martian Lander looking for water and whatnot there at the Martian south pole. But the glory days of the "faster, better, cheaper" space probe era at NASA are coming to a close.

Cassini was my favorite of all the probes (at least until they arrive at the edge of the Oort Cloud). These pictures are a couple years old by now, but are truly remarkable. Somebody on the Cassini team clearly has an eye for composition.


That's Saturn on the left, the rings, and Titan on the right (if you look at Saturn through binoculars, you can usually see Titan hanging off to the side, quite brightly). Lots of the pictures that Cassini took were in black and white, to save on data. I now next to nothing about Art Deco, but the B&W shots always remind me of Art Deco.


That's Titan and Dione at bottom, Prometheus at the center; Telesto a mere speck in the darkness above center.


Saved the best for last. This has been called the most stunning photograph of all time. That might be taking things a tad far, but it is pretty amazing. You really need to click on this to enlarge it and get the full effect. I've read that when this image was first released, someone in th crowd burst into tears, so moved by the beauty of it. It'a a picture of Saturn backlit by the sun (something you can't see here on Earth, as the Sun and Saturn are on either side of us) which revealed never-before-seen details, like Saturn having 2 rings that no one had ever seen before. If you look closely you can see several of Saturn's 60-ish moons flitting about amid the rings.

I got all these pix at the Cassini Favorite image contest. The winners are here. The nominations (way more interesting) are here. In addition to lots more pictures, there are breath-taking movies (which I would've shown if I could have embedded them) of moons creating ripples in the rings, of ice geysers, of moons racing each other across the blackness.

I'm off to Rockygrass! Best weekend of the summer. I will listen to bluegrass with my feet in the water, a beer in my hand, my wife and children and good friends splashing in the shining water before me. See you next week.

Threading a Needle

One of the weirder critters orbiting Saturn is Enceladus, a moon with huge ice-geysers spewing from its south pole. No one knows exactly what's up with those geysers, though the leading theory seems to be internal heating due to the stresses put on the moon by Saturn's gravity. Predictably, the Babe in the Universe believes it is a good place to look for a black hole. Who knows, she may be right; she's much smarter than I am.


At any rate, NASA pulled off a seriously cool trick earlier this week, by flying the Cassini probe straight into an ice-geyser, skimming just 30 miles above the surface, while going 32,000 miles an hour. It must have been cool to see (and since water implies life, maybe it was seen). I read that some sensors shut down at a crucial moment, leaving a big hole in the data, but Cassini is gonna do nine more fly-bys, so the mission is hardly a failure.

The coolest thing about Enceladus is that it is responsible for its own ring. The astounding picture below actually shows the geyser dumping ice and water vapor into Saturn's E ring. That shot just amazes me (click it to enlarge it). Apparently they got the image by flying Cassini into a spot where the Sun was blocked by Saturn, but light was still shining on the ice crystals as they fell into orbit.

I don't have any fancy-pants literary metaphor to hang onto the ice-geysers, or the Cassini fly-by, or Enceladus. I suppose I could come up with something, but it would pale when compared to the reality of the whole thing. So I'll leave it alone. You can check out the raw images from Cassini here.

Hither and Yon

There's alotta weird stuff orbiting Saturn besides those magnificent rings. Shepard moons, Trojan moons, moons that switch orbits, moons with ice-geysers, spokes and scallops in the rings, mysterious hexegonal clouds.

And it turns out there may be a black hole orbiting it as well. I don't know whether to trust the veracity of someone called A Babe in the Universe, but she has enough blog cred to be included from time to time in the Carnival of Space, and seems to be an actual cosmological scientist. She certainly not one of the Art Bell crowd. And to her credit, she doesn't say there it is a black hole, simply that there is an anomaly. And that the anomaly may be a good place to look for one.



In a nutshell, there's a mysterious clump of charged particles pulling Saturn's electrical field all out of whack. That's fact, not theory; the Cassini probe spotted it. No one knows what it is. But one possible explanation is a black hole. The thing behaves the way a black hole would behave.

The Babe in the Universe has a Big Idea: there are black holes all over the place. Orbiting Saturn, in the center of stars, in the center of planets (including Earth), floating all over the universe hither and yon (maybe one at the bottom of your cup of coffee, or one in that hairball the cat just puked up). Because most black holes - again, according to the Babe - aren't the result of the gravitational collapse of stars, which is the conventional theory, but rather have been around literally since the beginning of time: primordial black holes, left over from the big bang. It's a very cool idea, and an explanation for where all that missing mass is. It's not accepted theory or anything. And I don't know enough about cosmology to know how plausible it actually is.

But is sure is fun to think about.

Janus and Epimetheus

I used to be scared that the universe was a genuinely random place. Scared there was no destiny, no design, no wheels within wheels.

Fuck that.

In the last 10 years or so I’ve come to not only accept randomness but embrace it. Which is part of my fascination with orbital mechanics (the overarching theme of this blog), the complex structures and counter-intuitive oddities created by the accumulation of countless collisions and near misses. By chucks of rock hitting the sweet spot of a gravity well at just the right angle and speed.

For instance, there's these guys:



This is a picture of Janus and Epimetheus, two moons orbiting Saturn just outside the F ring. Their orbits are very close, about 30 miles apart. And every 4 years or so, when they line up just right, they switch orbits, narrowly avoiding a collision in the process. 4 more years, they switch back. The orbits are actually pretty stable.

As much as anything is stable out there.

More on that later.