Zombies in Space

The Damned Thing just won't die.

The Galaxy 15 C-band telecommunications satellite went off orbit and out of control in April. It can't be repositioned, it can't be turned off, and interference from it is disrupting signals from other satellites.

Admittedly, the reason this is in the news at all is likely because someone nicknamed it a "zombie satellite." To my mind that is somewhat of a misnomer, as a true zombie satellite would not only kill other satellites but turn them into other zombie satellites as well. The glitch would go viral. Sadly, all the Damned Thing does is temporarily disrupt signals.

Still, scientists predicted it would die in August, after all its power was drained (the different orbit means its solar panels are not pointed directly at the sun anymore). What they didn't count on was that the satellite is able to save energy during periods it is in the Earth's shadow. No one expected that to happen. So it's still alive, still kicking, still spreading its zombie goodness throughout the solar system.

They have had to change the orbits of 6 satellites so far to avoid the zombie, and expect to have to change the orbits of 7 more between now and December. By then, the experts say it should die.

I'm hoping otherwise.

Copenhagen Suborbitals

Copenhagen Suborbitals is trying to put a man into space this weekend, by launching their very own rocket on Saturday. It'd being launched from a floating platform also of their own design. The floating platform is being towed into place by the Nautilus, a submarine also designed by these guys. So, to recap: their own rocket, floating launch platform and submarine. Clearly, a creative bunch. Nemo would be proud.



Copenhagen Suborbitals is a non-profit group, entirely funded by donations. Go visit their site. You can give them some money, or at least buy a very cool t shirt, like I did.

My favorite aspect of this is that they named the rocket Tycho Brahe, one of my favorite astronomers ever. Tycho had a silver nose, as his actual nose was cut off in a duel. He made incredibly accurate measurements of the stars and planets, and their positions in the night sky, but never concluded the Earth revolved around the sun, choosing to instead cling to his own theory that the Earth was the center of things, and the movements of the planets could be explained by "epicycles," or circles within the orbits. After his death his assistant, Johann Kepler, took Brahe's results and pretty much nailed down the heliocentric solar system model, by deducing the heartbreakingly elegant three laws of planetary motion from the data.

Temporary Moons

Jupiter has at least 63 moons orbiting it, and thousands of asteroids and other rocks littering its orbital path (not considered moons because they don't revolve around Jupiter). Between 1949 and 1961 it had another one, when Jupiter grabbed a comet and turned it into a moon. The comet goes by the romantic name of "147P/Kushida-Muramatsu" and it hung around for 12 years, roughly two orbits, before traveling back out into the black.

Like so much in the world of orbital mechanics, the closer you look at this, the weirder it gets. The comet is a "quasi-Hilda comet," meaning it's from the Hilda family of asteroids. These asteroids - there are thousands of them - form a triangle within Jupiter's orbit, around the 2 main Lagrange points (where the gravity between Jupiter and the sun cancel each other out), and the point opposite Jupiter. You don't see alotta triangles in space. Circles, spirals, ellipses are the usual suspects.



Apparently, according to the wiki article, the triangle "breathes," meaning the density of the wall of the triangle relative to the points is constantly shifting (at least, that what I think it means; I've read the sentence about ten times and am still not sure).

As I've said a hundred times in these posts, random movements form non-random structures, many of them quite complex. The idea that they are formed due to a few simple laws - namely Kepler's three laws of planetary motion - is to me infinitely more interesting, and more beautiful, than the idea they were put in motion by some kind of intelligent design.

I pulled the illustration of the Hilda triangle from the wikipedia article.

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.

Very Big and Very Weird

There's a cool little dance going on in the western sky for the next several days. The new moon is on the 2nd (meaning you can't see it, because the sun is almost directly behind it), but after that it will appear in the west as a young waxing crescent moon. A beautiful sight in itself, but there will also be three bright objects near it: Saturn, Mars and Regulus (the brightest star in Leo). They'll shift positions slightly over the next several nights, and create quite the pretty picture. On the 10th, Mars and Saturn will be at their closest to each other, .7 degrees apart (of course they're still 800 million miles apart, but let's not split hairs).

Plus, while all this is going on, over in the east, Jupiter will be rising at the same time. On the 4th you're gonna be looking up at the sky anyway, for fireworks, so take a couple minutes and try to find some planets. Show your kids! Impress your girlfriend! Or boyfriend, of course.

I stole the image from Sky and Telescope's excellent This Week's Sky at a Glance.

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I've fallen off the orbital mechanics train the last couple weeks, so I'm making up for it today with a double post of things orbital.

100 years ago this week something very big and very weird exploded in the sky above Tunguska River in Siberia. I remember the small thrill I got reading about it when I was a little kid. It flattened trees for 800 miles, lit up the night sky half a world away with luminous clouds, set seismograph needles a-twitter, painted halos around the sun. There was no crater, and no remnant of the explosion has ever been found (admittedly, no one bothered to examine the impact site for 19 years). Ground zero was easy to find only because the trees flattened in a circle, all pointing toward the center. This odd lack of any debris has spawned a bucket of strange theories, ranging from collisions with anti-matter and black holes to alien spacecraft, nuclear fusion, and methane explosions. The more likely theory is that an asteroid or comet exploded a few miles above the ground. There is a little round lake about six miles away, with a peculiar cone at the bottom, that points to this theory (i.e. - a piece of the asteroid thrown by the explosion created the lake). But no one really knows.

A pretty cool deal, though, regardless of the specifics. It's known as the Tunguska event. It even sounds cool. Very X Files.

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This just in! I read this morning that Nikola Tesla, the guy who invented both the radio and AC power before going utterly freakin nuts, caused the Tunguska event. According to "sources," he test-fired a death ray on the evening of June 30, 1908, and once he found out about the Tunguska event, he dismantled the weapon, deeming it too dangerous to remain in existence.

Easily he coolest explanation I've ever heard. Wish I'd known about it when I was a kid. Gotta call Art Bell.

The YORP Effect

Since asteroids are basically just witless hunks of ice and rock, you'd think they'd live pretty boring, solitary lives. But you'd be wrong.

They pair up frequently, and become binary asteroids co-orbiting a central point. Sometimes they form threesomes. Woo-hoo! Sometimes they have tiny moons, tagging along after them. This picture is of Ida and Dactyl, an asteroid and its moon, but has always reminded me of a mother and child.


I love this picture. Dactyl is the little one.

Others hang around together in groups, often hitching rides in the LaGrangian points of planets (where the gravitational influences all balance out). i imagine them smoking cigarettes, whistling at girls, and trying to scrape up enough money for a six pack.

They also, improbably, begin to spin in the same direction, at the same speed, or specific resonances of that speed (it's called the YORP effect, named after the initials of the guys who figured it out). This has always struck me as particularly weird, that unrelated asteroids would mimic each other's orbital behavior. Apparently it has something to do with the pressure of sunlight on the surfaces of the asteroids, so that like sailboats on a lake, they'll all react similarly to the solar wind. But i like to think of it as a complex dance. It heartens me to realize that the universe rarely allows things to work alone as independent operators, whether those things be space rocks or ants or humans. I don't wanna say that randomness doesn't exist. Randomness is all. But from randomness spring unexpected patterns, complex structures, and hopelessly entangled relationships.

We are never, ever alone.

Even when we wanna be.

A God of Ice and Rock

One of the cooler things about the Oort Cloud is that it may not even exist.

It is purely theoretical, and has never been directly observed. The reason for its theoretical existence is because it explains the behavior of comets. Comets seemingly come out of nowhere, and while most of the rest of the solar system stays within the plane of the solar system (except for that contrarian former planet Pluto and the odd asteroid here and there), comets come barreling in at all possible angles.

So there's that.

Also, if comets were simply orbiting elements of the solar system, zooming toward the sun every few hundred years or so, there wouldn't be any more comets. The solar system has been around a very long time, and comet orbits are by nature pretty unstable; after this long a time most comets should have collided with a planet or the sun, or been flung out of the solar system by gravity, or simply broken apart by close passes to the sun.

And the Oort Cloud explains that pretty well too.


Here's the theory: there is a great cloud of icy rocks surrounding the solar system in a sphere (as opposed to a disc), rocks left over from the birth of the solar system. The outer edge of the cloud is VERY far away, around a light year (the closest star, by comparison, is about 4 light years away). Since these iceballs are so far away, they are only tenuously connected by gravity to the sun, and thus are easily pulled out of orbit by passing stars, passing black holes, the plane of the galaxy, etc.. When something passes by, it affects the orbits of what it encounters. If that something is large enough, and passes close enough, everything in the Oort Cloud goes a little nutty. Orbits near the cosmic interloper change, and there is a cascade effect where objects with changed orbits change the orbits of other objects, which in turn affect other orbits, which in turn affect other orbits, on and on.

The result is the the solar system gets pelted with iceballs, like pellets shot out of a shotgun. Which helps explain all those craters on the various moons and planets out there. And helps explain as well why there is a mass extinction event here on Earth every several million years (tangentially related is the idea that every time we pass through the plane of the galaxy, roughly every 32 million years, the Oort Cloud gets jostled and everything dies; the fossil evidence bears this out).

It's also an explanation for those uncommonly beautiful objects occasionally gracing our skies, improbable tails arching across the sky like a bridge to a foreign land.


Comets might even explain the existence of life itself. They contain a lot of water, and are widely theorized to contain the amino acids responsible for life as well. So comets may have brought life came to Earth, and perhaps others places as well.

So. Let's recap. It might or might not exist. It had been around since the beginning of the world. It explains the physical world around us. It graces us with uncommon beauty. It is responsible for mass extinctions, and perhaps for the origin of life as well.

Might exist, might not. Timeless and beautiful. Responsible for the life and death of worlds.

Remind you of anyone?

Pink Moon

Lil Hucky, the little Clowncars and I ventured out at sunset to watch this month's full moon (called the pink moon, Hux tells me, named after trees that bloom pink blossoms this time of year). We do this fairly often. It was cloudy, so the moon was less than spectacular, but I learned a little trick. We always park in the same spot to watch moonrise, and we always guess where on the horizon it will come up (the person with the closest guess "wins"). And while we were sitting there in the car, an extremely simple way to predict where the moon will rise occurred to me: look where your shadow is pointing! That is where the moon will rise. Cool, eh? And so simple. This'll only work for a full moon (as the sun and the moon are only directly opposite each other then), but, at least this time, it worked like a charm. My obsessive interest in orbital mechanics pays off!

Sadly, I told my family immediately upon figuring it out and thus cannot use my newly-gotten knowledge to win the moonrise guessing game. I can only use my powers for good, not evil. I'm like Gamera!

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In other news, I found an answer to the baseball-thrown-from-the-space-shuttle question at the Straight Dope. Not an unimpeachable source, but a pretty good one. And amusing to boot. According to them, throwing the baseball toward Earth, or away from Earth, will not affect the orbit of the baseball at all. As Larry Niven (a GREAT sci-fi writer) puts it, "East takes you out, out takes you west, west takes you in, and in takes you east." Orbits depend upon speed. If you don't change the speed of the baseball, you won't change the orbit.

So, the only way to change the orbit of the ball so that it'll fall to earth is to throw it straight back from the shuttle, to slow it down. But (and the math here is seriously over my head, so I'm trusting the Straight Dope) a ball thrown at 92 mph wouldn't come close to getting it out of orbit - you'd be able to drop the orbit a 100 miles or so, but not all the way to Earth.

Atmospheric friction would eventually bring it down. But our premise here is a crowd at Yankee Stadium waiting for the ball to fall so the ump can shout "Play Ball!" And unless the crowd is willing to wait a few years, it's not gonna happen. Those Yankee fans are a notoriously impatient lot.

Bullets and baseballs

So, I read yesterday that some astronaut on the space station was gonna throw out the first pitch from space for the Yankees-Bosox game. How does that work, exactly? Is he really gonna throw it from space into Yankee stadium? It seems unlikely. I missed the beginning of the game because of soccer practice (which got snowed out, another strange story, but I digress), so I never got to see the pitch thrown. I assume he lobbed a throw inside the space station, it got shown on the jumbo-tron at Yankee stadium, the umpire said "plsy ball," life goes on. But I don't know. All the press releases and coverage of the game just said he threw out the first pitch from space. No more explanation. You'd think somebody in the newsroom would have enough intellectual curiosity to find out exactly what that means. And then tell us.

But no.



Again, I digress.

My main point is, I don't think you can throw a baseball from the space station to Earth. If I remember my high school physics, all actions produce equal and opposite reactions. So, if you tried to throw a baseball from space, the ball would go toward Earth a little, the space station would go away from Earth a little, they'd both end up in orbit. Because the baseball is already falling. That what orbits are: objects in freefall around other, larger objects. Caught in the sweet spot where centrifugal force balances out gravity. That's what Newton really figured out when that apple fell on his head. Not that gravity caused the apple to fall. But that the falling apple and the orbiting moon are both exhibiting the exact same behavior. Both are in freefall.

But something tells me my logic regarding the baseball is wrong. Because if you fired a gun toward Earth, surely the bullet would hit. It wouldn't go in a straight line, it'd travel in a spiral, but ultimately it would hit. The bullet would have enough energy to cancel out the centrifugal force. I think.



So maybe the deciding factor is how hard you throw the baseball. I don't know.

Anybody out there know? Anybody out there care? Anybody out there spend inordinate amounts of time thinking about useless minutia like this?

Probably.

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Since I don't have an end to that thought (it's basically just an extended question), I'll post a wonderful picture I stole from Primordial Slack. She stole it from someone else. So I can't give credit. But it sure is cool.

Mini moons

Interlopers. Hangers-on. Hitch-hikers. Parasites. Guardian angels. Extended family. Entangled relationships from which you will never escape.

Take your pick.

The earth has more than one moon.

Okay, technically they aren't moons, since they don't rotate the earth, but are instead "co-orbital objects," that gravitationally interact with us as we make our way around the sun. They don't shine, they're too small to reflect back much sunlight, they are dark chunks of rock, leftover from the birth of the solar system.

And there are several of them, but I wanna talk about the largest one today.

3753 Cruithne (pronounced "krooy-nyuh," named for a King of the Celtic Picts) is the coolest of all, because of its very strange horseshoe shaped orbit. Of course, all orbits are ellipses, but from the point of view of the earth, Cruithne's orbit is a set of spirals that, taken together, form a horseshoe (the picture below is a simplified version). I'd be lying to say I understand it fully, and I've been pondering it for weeks now, but the result is a stable and carefully choreographed two-body orbit where neither object will hit the other one.



Please don't this this as a sign of intelligent design, or some uber-mind in charge of a great celestial clockworks. It's not. The reason Cruithne is in such a stable (albeit intricately choreographed) orbit is simply because if it were in an unstable orbit, it would have been flung into space, the sun, or even the earth. Like that thing that killed the dinosaurs. It's the cosmic version of "last man standing," and if it is evidence of anything, it is evidence of endless possibility, of the bounty of patterns nature can form from such simple building blocks.

Full Moon

There's a total lunar eclipse tonight, from 7 p.m. til 10 or so, Mountain Time. But that's not what I'm writing about.



Lunar eclipses always occur during full moons. And full moons always rise exactly at sunset (if that seems mysterious, a pencil and paper will help you figure out why). And that's what I'm writing about: that exact moment when the sun is perched on one horizon, the moon on the opposite. Happens once a month. It's a charged moment, as if the moon, sun and Earth are all in precarious balance for a brief instant. Time seems to slow down to accommodate it, balanced as well. Then the moon goes up, the sun goes down, the moment is over, time snaps back, life goes on. We try to experience it firsthand several times a year, by driving out to the bank of the Arkansas River to watch the full moon rise. The girls, predictably, are more interested in playing with the car radio than watching the moonrise.

In "Gilead," one of my favorite books ever, Marilynne Robinson does a much better job of of describing it than I:
"Then I realized that what I saw was a full moon rising just as the sun was going down. Each of them was standing on its edge, with the most wonderful light between them. It seemed as if you could touch it, as if there were palpable currents of light passing back and forth, or as if there were great taut skeins of light suspended between them. I wanted my father to see it, but I new I'd have to startle him out of his prayer, and I wanted to do it the best way, so I took his hand and kissed it. And then I said, 'Look at the moon.' And he did. We just stood there until the sun was down and the moon was up."

Such clear, simple writing.

So bundle up and go outside tonight (or stay in the car with the heater on like we do) and look up at the sky for awhile. See the moon and the sun and the Earth at play.

Adrift

When I first started this blog, about a month ago, I was pretty psyched about the possibility of an asteroid hitting Mars, perhaps right in front of one of the Mars rovers, giving us all a front row seat for the collision. Odds were at 1-in-75, then jumped up to 1-in-25, then down to 1-in-40, then, sadly, 1-in-10,000.

Turns out that it probably didn't crash into Mars.

Where is it now? No one knows.

It's lost.



The thing (it's in the little red circle in the middle of the picture) has been slingshotted by Martian gravity straight into the unknown (I can relate), and while Mars doesn't have enough gravitational muscle to sling it clear out of the solar system, it does have enough of an effect to seriously warp its orbit. So now it's adrift, untethered from its previous influences, and will slowly accumulate new influences, settling finally into a new orbit: stable, but very different. There are way too many variables for astronomers to calculate the new path.

Again, metaphors abound with this orbital mechanics stuff, which is why I like to write about it. And I won't belabor the metaphor, other than to say that I find the whole process oddly comforting; some random rock being wrenched out of a stable and comfortable orbit, thrust into a whole new family of gravitational influences, where, given enough time, it will settle into stability again. No collisions, nothing spilled. Just another trip into the unknown. Until gradually the unknown becomes, well, known.

I like that.

Gegenschein

I saw this once.



Saw it during a very dark night camping at Dinosaur National Monument, the same night I saw the Andromeda galaxy with my naked eye for the first time. The tequila helped.

Gegenschein means counter-glow in German, and that's just what it is. It's a very faint glow, just opposite the sun (yeah, I know, it's night, so the sun is below the horizon; it's just opposite where the sun would be if you could see it). Gegenschein is caused by sunlight reflecting off dust in the plane of the solar system (which is why it shows up directly opposite from the sun). The dust is made of splinters from asteroid collisions, from the tails of comets, from the leftover bits of the formation of the planets. It's quite literally older than the world itself. Gave me goosebumps at the time (as did Andromeda).

Again, the tequila helped.

About the title

The Oort Cloud is a sphere of comets (sans tails) surrounding the solar system about a light year away from the sun. Think of the cloud as a hard candy coating, the solar system as a chewy nougat center. Most of the objects in the Oort cloud have been there for billions of years, traveling in lazy, placid orbits. Every once in a while something big and ornery and entirely unexpected comes waltzing through, twisting the orbit of every object it encounters, flinging iceballs in all directions.

There's a metaphor in there somewhere.

Sometimes the iceballs are flung toward us, and they develop tails as they near the sun. The big, glitzy comets naked-eye comets show up about once a decade, but with a good pair of binoculars you can easily spot one or two small comets a year, even with the light pollution of a medium-sized city. I look for them sometimes, in the back yard, while the rest of my family sleeps. They are easy to spot, fuzzier than the surrounding stars in the background, often trailing faint ion tails.

I like the metaphors offered by old-school Newtonian physics. I'll leave non-local effects, entanglement, quantum mechanics and string theory to others. I prefer the elegance of Kepler's Laws, seemingly random structures, the dance of mass and gravity, the aftermath of great collisions. I like the inevitability and predictability of orbits. I like how almost everything in the universe is a sphere or a disc. I like that nearly everything spins.

I like how nothing is new, everything is a result of previous cataclysms, the pieces merely rearranged.

I can relate.