Wednesday, February 26, 2014

We've Got A Trojan

Recently I wrote about how Pluto, the former planet, got demoted because it hasn't cleaned up its neighborhood of space debris. It's not that Earth is completely tidy, but at least it's not surrounded by crud. This is one of the attributes that allows us to call ourselves a planet. (Also, we're the ones who got to define "planet.") There are asteroids and meteors and comets and other dust bunnies in the vicinity but for the most part our planet has long since vacuumed up everything major in the region. The odd space rock will wander on through, but those don't count against us; we're just being hospitable, even to the point of occasionally giving them a soft spot to land. (Sorry about that, dinosaurs. And Russians.)

We do get to keep a moon. A planet can accumulate a pet moon in a number of ways. It can start out with a gang of dust and gas around it that begins to associate ever more closely until it spheres up. Or, it can steal an already-made one that was just passing through. The way we got our moon was that somewhere along the line something huge smacked into us and knocked a chunk out. So our moon is like the loogey we hawked that didn't quite clear our shoulder.

The reason there's ever a solar system in the first place is that masses are attracted to each other, because space is a big and scary place to be by yourself; we call it gravity, but it's really atomic loneliness. Of the stuff in the disc that became our solar system, almost all of it got claimed by the sun itself, and the leftover dribs and drabs became us, our planet buddies, and other miscellany. Everything started to bunch up. We get something solid to stand on because we are close to the fire, so all the rocky bits and iron and metals with a high melting point were at our disposal. There isn't that much of that. Most of the stuff running around the sun, by far, is in the big gas planets. Jupiter's the biggest, having formed first, and Saturn, Uranus, and Neptune had to make do with what was left over. I'm not sure you can land on Jupiter or Saturn, although you could maybe sort of land through them. Uranus and Neptune are icy, so you could stand on them. Briefly.

Artist's Depiction
We're all very fond of our moon and many of us have thought it would be cool if we had another. So a few years ago we found out we do! Sort of! We have our own Trojan Asteroid, and it orbits with us, if not around us. A trojan asteroid is a space rock that travels in the same orbit as a planet or a planet's moons, simply by positioning itself at a Lagrangian point. So there you have it.

Lagrangian points are certain locations--five of them--at which the combined gravitational pull of two massive objects, like the Earth and the sun, allow a smaller object to travel with them rather than going haywire. Our trojan is leading us around the sun, even though it is only a thousand feet across. It's like a weiner dog straining at the leash. I don't know why it's called a trojan. It has no protective qualities at all.

Since there are only five Lagrangian points associated with the Earth and the sun, you'd think scientists could have found the sucker before now, but it's little and hard to see in the daytime, which is all the time. But also, it doesn't just hang out at the predicted point. It oscillates around it, wildly, in what is called a "tadpole-shaped loop," and if that doesn't cheer you up, you should probably seek pharmaceutical help. Scientists might have been encouraged to refer to its path as a tadpole-shaped loop in order to avoid calling it a spermy loop. They're in enough trouble with the Trojan thing.

So we can't gaze on our trojan at night, but still it's ours, and the least we can do for it is give it a better name than "2010 TK7." I'm going with Skippy.

44 comments:

  1. If we ever send a manned expedition to the Trojan, the spaceship should be in the form of a wooden horse, with the astronauts inside.

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    1. And the little Trojans will say "oh look! A horse! Let it in!"

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  2. Well, I learned something new today...I think.

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    1. Yes. You learned Lagragian points, and you learned them hard.

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  3. Traditionally the asteroids near Jupiter were named after characters from the Iliad. By extension objects exhibiting similar behaviour elsewhere then are also called Trojan asteroids.
    I did not know that previously, but had heard the term ‘Trojan planet’ before to describe the possibility that two whole planets might share one orbit.
    Another more exotic possibility is where two planets orbit around each other, the orbital centre being the space between them.

    There’s an old sci-fi film wherein an astronaut ‘returns’ to Earth only to find everything is reversed – because he has actually arrived at a duplicate Earth occupying the same orbit, but on the far side of the sun, that is a mirror copy.

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    1. OMG! My mole would be on the other side!

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    2. The movie you are describing is "Journey to the Far Side of the Sun". Here is the synopsis on the IMDB:

      http://www.imdb.com/title/tt0064519/plotsummary?ref_=tt_ov_pl

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  4. I've gotten to the point where I live for your science lessons.

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    1. I think you need a hobby, but thank you.

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  5. Anything on a tadpole-style loop is okay in my book.

    And I, too, shall call it "Skippy".

    Pearl

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  6. That was all in English, right?
    Sigh. A scientist I am not.

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    1. Here you go, the easiest Lagrangian point to "get:" a point real close to the earth but in between the earth and the sun, just where the gravitational pull from earth almost overcomes the pull from the sun.

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  7. I still confuse asteroids and hemorrhoids.

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    1. Insert Uranus joke here, or wherever you'd like.

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  8. A "tadpole-shaped loop". Well, that makes my day. I'm waiting with eagerness to find something that orbits in a paramecium-shaped loop. Or better still, an amoeba-shaped loop. I wonder how they determined it was a tadpole and not a paisley...

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    1. If you had a bunch of them in one spot it would totally be a paisley.

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  9. I understood approximately two words here: wiener dog, and tadpole. Wait, that seems to be three words.

    Apparently both science and math are beyond my grasp.

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    1. No ma'am. If I had you here I would pound it right into you.

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    2. Is that what's known as hands-on learning?

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    3. Yes. You have to knead the receiving brain until it's spongy, and then you can pound in the information. Doesn't work on Republicans.

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    4. Then the division in the country is the Spongy Brains and the Hard Heads?

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  10. Who's the real estate agent for that property?

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    1. Are you wondering if there's a goat clause?

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    2. A opposed to a Santa Clause?

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  11. I assume everything written before the 'naming of the Trojan' part was just filler so I'm right there with you on calling 2010 TK7 Skippy. Done and done.

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    1. Aw, you're not even trying! But good attitude, anyway.

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  12. I'm very enamoured of Skippy, our LaGrangian lovechild. Think they might even name a kids' show after him. Her? Herm? Mmmm, neutral pronouns...

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    1. You're not supposed to feel that way about your OWN KID!

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  13. Jupiter is theorized to have a solid core, possibly one giant diamond. So if you could make a spaceship that could survive the massive pressure of Jupiter, you could land on its core. Arthur C. Clark in his book, 2061 or 3001 has astronauts encountering Jupiter's core on Europa after it was ejected in the alien makeover in 2010 that makes Jupiter into a second sun. I never have heard whether Saturn is supposed to have a core.

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  14. Atomic loneliness is a PERFECT phrase. Thank you. And Skippy (or perhaps Brad) work for me as names for our furtive trojan.

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  15. Replies
    1. Nobody's known it for long, 'specially not the likes of us.

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  16. Well, this screws up MY astrology chart!

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    1. Yeah, if the moon is in your asteroid, it does.

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  17. I thought you were going to write about some Trojan virus your computer had picked up, instead I learned a lot about planets and moons which I will forget as soon as I move onto the next blog....

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  18. "The reason there's ever a solar system in the first place is that masses are attracted to each other, because space is a big and scary place to be by yourself; we call it gravity, but it's really atomic loneliness."
    Stunning! Set that to a country background with a slide guitar, and you've got sheer poetry!

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    1. Yeah, but I'd totally need that slide guitar.

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  19. I like Skippy - a good name for nether-moon. We may not have much debris to navigate, but we are adding to it with our own space junk.
    the Ol'Buzzard

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  20. What the ol'Buzzard said. We are traveling with a cloud of debris buzzing around us like flies around a manure wagon. And slowly, slowly, they are all falling back to earth. Because space is a big, scary place to be and everyone longs to go home.

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