First Earth Trojan Asteroid Discovered

The Bad Astronomer writes "Astronomers have found the very first Earth Trojan asteroid, a rock that more-or-less shares Earth's orbit around the Sun. Seen in data by NASA's WISE mission, 2010 TK7 is about 300 meters across and leads the Earth by 60 degrees around the Sun. Trojans have been seen for Jupiter, Neptune, and Mars, but this is the first for our planet."

Comments

How does a condom company sponsor an asteroid?

[Anonymous Coward]

It seems like the asteroid would do just find without corporate sponsorship.

Trojans!

[Oxford_Comma_Lover]

... the very first Earth Trojan asteroid,

Curse its sudden but inevitable betrayal.

Re:Trojans!

[frosty_tsm]

... the very first Earth Trojan asteroid,

Curse its sudden but inevitable betrayal.

Now die!

Re:Trojans!

[Rasperin]

Let's just hope it doesn't break at a very inconvenient time :P

Re:Trojans!

[Alien Being]

Ribbed for her pleasure TM.

Finally

[avgjoe62]

The Earth has abandoned all that parochial school teaching and pick up some Trojans...

First Earth

[SnarfQuest]

Is First Earth anything like Second Life?

Re:First Earth

[uvajed_ekil]

Here's something you could use, though I doubt you'll get it. http://en.wikipedia.org/wiki/Reading_comprehension

Re:First Earth

[Anonymous Coward]

Here's one for you http://en.wikipedia.org/wiki/Humor#Understanding_humour

L4

[Stavr0]

This one should be called 'Lagrange'

Re:L4

[Anonymous Coward]

This one should be called 'Lagrange'

Only if it has a lot of nice girls.

Re:L4

[Jah-Wren Ryel]

Rumour spreadin' a-'round in that Texas town
'bout that rock outside La Grange
and you know what I'm talkin' about.
Just let me know if you wanna go
to that stone out on the range.
They gotta lotta nice girls ah.

Have mercy.
A haw, haw, haw, haw, a haw.
A haw, haw, haw.

Well, I hear it's fine if you got the time
and the ten to get yourself in.
A hmm, hmm.
And I hear it's tight most ev'ry night,
but now I might be mistaken.
hmm, hmm, hmm.

Ah have mercy.

Re:L4

[h4rr4r]

Way to ruin the joke.

Re:L4

[Anonymous Coward]

Shame I gave away all my mod points ^^^ shoehornjob

Re:L4

[Anonymous Coward]

We've already got 1006 Lagrangea.

Re:L4

[camperdave]

It must be quite the asteroid to have an entire planet in it's L5 Lagrange point.

Re:L4

[Anonymous Coward]

Ah how how how how.

Re:L4

[phrostie]

we should name it Dusty Hill

Re:L4

[History's Coming To]

Yup, I'm with you and Clarke. This is an L4 object, 60 degrees ahead of us.

Re:L4

[mark_elf]

Is the earth in a tiny Lissajous orbit around it's L5?

Isn't this a ticking time bomb?

[Anonymous Coward]

If the orbit isn't exactly the same, then I'd expect the distance to slowly become smaller (either the asteroid revolves faster around the sun or slower). Won't it enter Earth's gravity well and crash into us when it comes to close?

Re:Isn't this a ticking time bomb?

[iggymanz]

No, the Lagrange points are stable garbage dumps for planets to put "small" things of 9% of its mass or less, the stuff stays there. It's one of the ways a planet clears its orbit.

Re:Isn't this a ticking time bomb?

[Cyberax]

And if a LOT of stuff accumulates there - you get a new moon. Eventually.

That's how we got our favorite Luna, probably.

Re:Isn't this a ticking time bomb?

[jojoba_oil]

Being that this is in the same orbit around the Sun as Earth and it will stay there, is this a viable location for a human colony?

First space colony would be the moon, then this asteroid, then Mars?

Re:Isn't this a ticking time bomb?

[element-o.p.]

From TFS:

...2010 TK7 is about 300 meters across...

It would be kind of cramped, and I rather suspect the gravitational pull would be negligible for all practical purposes.

Re:Isn't this a ticking time bomb?

[spaceyhackerlady]

It would be kind of cramped, and I rather suspect the gravitational pull would be negligible for all practical purposes.

Assuming the same average density as Earth, the surface gravity would be about 1/50000 that of Earth. I make it 0.0002 meters/second squared.

...laura

Re:Isn't this a ticking time bomb?

[HaZardman27]

Thanks for the explanation. My first thought upon reading this was "wait a second, didn't Pluto lose its status as a planet in part because it had not cleared its orbit?"

Re:Isn't this a ticking time bomb?

[mister_playboy]

A significant fraction of the earth's density (~20%) comes from gravitational compression.

A smaller body with the exact same material composition as Earth would have lower density than the Earth does.

Re:Isn't this a ticking time bomb?

[c0lo]

No, the Lagrange points are stable garbage dumps for planets to put "small" things of 9% of its mass or less, the stuff stays there. It's one of the ways a planet clears its orbit.

Theoretically you are right. Practically, the orbit of TK7 is actually unstable. Because TK7 executes some Lissajous orbit around L4 and the Moon orbit is eccentric (search for the "the case of the Earth-Moon system" in the linked page).

Re:Isn't this a ticking time bomb?

[instagib]

Which means that if you fart while sitting on the Asteroid you'll reach escape velocity.

Pluto rules

[SnarfQuest]

Since this trojan shows that the Earth hasn't cleared its orbit, does that mean that Earth is no longer considered a planet?

Re:Pluto rules

[Bob the Super Hamste]

Given its position earth will never clear its orbit, but then I guess Jupiter shouldn't be considered one either as it also has an asteroid trapped in one of its Lagrange points.

Re:Pluto rules

[iggymanz]

Nope, putting small objects into a Lagrange point of stability is one way a planet clears its orbit.

Re:Pluto rules

[LateArthurDent]

Since this trojan shows that the Earth hasn't cleared its orbit, does that mean that Earth is no longer considered a planet?

Being in a Lagrange point doesn't mean that the Earth hasn't cleared its orbit. Unless you want to argue that the presence of a moon means the Earth hasn't cleared its orbit. After all, the moon also roughly follows the orbit of the earth around the Sun.

Re:Pluto rules

[Bob the Super Hamste]

I should have corrected my initial post:

Given its position earth will never clear its orbit, but then I guess Jupiter shouldn't be considered one either as it also has an asteroids trapped at its Lagrange points, as does Neptune and Mars.

Re:Pluto rules

[marcosdumay]

Well, I guess that rule doen't apply to trojan points. Otherwise the list of planes would be quite small (4 now, but may quite well setle in 1 - Mercury - or 0 when we get better telescopes).

Re:Pluto rules

[Anonymous Coward]

Clearing the neighborhood is a bit more involve than just pointing out any object in the orbital path and screaming "So it's not a planet or Pluto is!!!onehundredeleven!!!"
 
I really don't understand the endless bickering over these points. So you'll have to call Pluto a dwarf planet to be technically correct. Ok. Is it really that big of a deal? No sane person is going to stab you with a ballpoint pen if you call Pluto a planet either. If anything, it's good that we have a solid definition today. They could have made the definition in such a way as to include Pluto but that would lead to a whole host of other objects being called planets too. The line needed to be drawn somewhere and this is where it was drawn. No one died because they did this. Just get over it already.

Re:Pluto rules

[idontgno]

Actually, the Earth-Moon barycenter follows an orbit around the Sun. It just looks like it's Earth's orbit.

Re:Pluto rules

[Anonymous Coward]

Planets can clear their orbits by placing things in their Lagrange points. Same way teenagers clean their rooms by shoving everything in the closet or under the bed.

Re:Pluto rules

[iggymanz]

I learned that trick way before I was a teenager. under the dresser behind shield of shoes was a good place too.

Re:Pluto rules

[TWX]

Given that the barycenter's center of mass is within Earth itself, I'm happy to call it Earth's orbit for simplicity's sake. Come to think of it, the only planet or dwarf planet whose satellite is massive enough to place the barycenter outside of the planet itself is Pluto.

I suppose that the astronomy and astrophysics communities could further refine the definition of planet based not only on size, but on the location of mass relative to a satellite...

Re:Pluto rules

[camperdave]

Count on zero. The Solar System is a messy, dirty place.

Re:Pluto rules

[Dthief]

no because its tiny...the other object needs to be comparable in size, like was the case with pluto and the plutoids (of nearly the same size)

Re:Pluto rules

[Dthief]

like your mom's coochie

Re:Pluto rules

[Chris Burke]

No planet has cleared it's orbit 100%, which is okay because that never was the requirement.

Earth has done the job of clearing its orbit 100,000,000 times better than Pluto has. it doesn't have to be perfect to clearly be in a different class.

Re:Pluto rules

[FrootLoops]

That seems problematic, with the variation in satellite size.

Re:Pluto rules

[Chris Burke]

It's not even necessarily about the size of other objects, but about the total mass of objects.

Pluto is a tiny fraction of the mass in its orbit.

Everything else in earth's orbit is a tiny fraction of it (not counting Luna).

Re:Pluto rules

[SEE]

The problem with the barycenter rule is that the Jupiter-Sun barycenter is outside the Sun. Do you delist it as a planet because it doesn't orbit the Sun, but a point outside the Sun?

What we really need to do is get rid of the idea that planets are going to be a short, enumerable list that elementary school students can memorize, and instead use it to mean any object, wherever it is, that's too small for its gravity to make it fuse but big enough to wind up in a round shape under its own gravity.

Re:Pluto rules

[mister_playboy]

The barycenter of the Sun-Jupiter system lies at 1.068 Solar radii from the Sun's center... i.e. outside the Sun itself.

Re:Pluto rules

[niktemadur]

Agreed, I've come to think that Phobos and Deimos should be reclassified as gravitationally trapped debris or something along those lines.
To qualify as a satellite, using volume percentages would be problematic in the realm of gas and ice giant planets, so maybe something along the lines of spherical shape would be the way to go.

Re:Pluto rules

[Dthief]

quoting from wikipedia (and thus the true gospel):

"In the end stages of planet formation, a planet will have "cleared the neighbourhood" of its own orbital zone, meaning it has become gravitationally dominant, and there are no other bodies of comparable size other than its own satellites or those otherwise under its gravitational influence. A large body which meets the other criteria for a planet but has not cleared its neighbourhood is classified as a dwarf planet. This includes Pluto, which shares its orbital neighbourhood with Kuiper belt objects such as the plutinos. The IAU's definition does not attach specific numbers or equations to this term, but all the planets have cleared their neighbourhoods to a much greater extent than any dwarf planet, or any candidate for dwarf planet."

http://en.wikipedia.org/wiki/Clearing_the_neighbourhood

Re:Pluto rules

[Anonymous Coward]

Do you delist it as a planet because it doesn't orbit the Sun, but a point outside the Sun?

Of course not, that would be stupid. However, it does mean that the Sun should be classified as a "dwarf star" and not a "star".

Re:Pluto rules

[iggymanz]

could you elaborate, was that the clarity, taste, aroma or bouquet?

Re:Pluto rules

[Chris Burke]

Don't neglect the "gravitational dominance" aspect, which can be calculated using the Planetary Discriminant (also described on that page), and essentially subsumes the "comparable size" part. If there were other objects of comparable size, then these metrics would necessarily be much smaller.

Re:Pluto rules

[nofx_3]

The problem is big and massive are two different things, and it depends on the material composition of the object. So we will end up with objects that are in hyrdostatic equilibrium that are smaller in diameter / size than other objects that are not. Take asteroid 4 Vesta for instance, it's larger in diameter than several objects that are in hydrostatic equilibrium, yet it is not itself. Also there are plenty of moons that are in hydrostaic equilibrium, according to your definition these would be planets. I think you at a minimum need to add "and orbit around an object which is massive enough for fusion to occur". Then of course we get into the weird world of brown dwarfs...

Re:Pluto rules

[Unkyjar]

I know it's outside the surface of the sun, but the corona is no longer considered part of the sun?

Re:Pluto rules

[NemoinSpace]

Contrary to overwhelming corroborating opinion, the sun, while not super massive, is not an "average star" - being more massive than about 80% of others. Look it up in a star catalog (instead of google)

Re:Pluto rules

[Anonymous Coward]

The problem with the barycenter rule is that the Jupiter-Sun barycenter is outside the Sun. Do you delist it as a planet because it doesn't orbit the Sun, but a point outside the Sun?

No, because it's not part of the definition of a planet that it must orbit a star. You can have rogue planets that are nowhere *near* a star. I would, however, change the definition to no longer say that Jupiter orbits the sun. I would say the Sun and Jupiter orbit each other.

And yes, I know that technically that applies to every massive object, including the Earth and the Sun. I'm just saying that you should only be allowed to simplify it to "body B orbits body A" if the barycenter of the B-A system lies inside A.

Re:Pluto rules

[MichaelSmith]

1.068

As numbers go that one is right up there with the angle subtended by the Moon and the Sun from the Earth. The apparent orbital resonance between Mercury and Earth is a great joke too.

Re:Pluto rules

[Dthief]

mostly taste

Re:Pluto rules

[jc42]

No, I think you meant: Jupiter shouldn't be considered one either as it also has thousands of asteroids trapped at its Lagrange points.

The numbers are quite a lot smaller for Neptune and Mars, though. And the total mass of Jupiter's Trojan asteroids is quite a bit less than Jupiter's mass.

The real exception continues to be our Earth, which shares its orbit with a dwarf planet with mass only about 1/80 of Earth's mass.

The real problem here is a technical term ("planet") whose definition includes features both intrinsic and extrinsic to the object it describes. Such definitions are always pitfalls when put up against the chaos of the actual universe.

Using a single term for a class of objects that includes both Mercury and Jupiter should also be considered a sign that the term is useless, and at least two new terms are what is really needed. Probably three, actually. But it doesn't look like we're going to get that solution any time soon.

My favorite explanation is that the fuss over "planet" was a joke perpetrated by some astronomers with a twisted sense of humor. They're still laughing at the fuss it produced.

Re:Pluto rules

[Teancum]

Arguably the Moon (aka "Luna"... which is just another way to say"Moon" in another language) is a dwarf planet, together with Io, Ganymede, Callisto, as well as Ceres and Pluto and a few other outer Solar System object in the Kuiper Belt. The whole orbit clearing thing is pure BS and eventually will have to be dismissed as a horrible idea.

If anything, I think Titan ought to be "promoted" to be considered a terrestrial-type planet together with Earth, Venus, and Mars as having a "thin" (less than 1% of the planetary mass) but substantive atmosphere. That it happens to orbit a very brown dwarf proto-star is irrelevant, or perhaps even proof of the idea.

Really, the whole thing with trying to define planets based on anything but their directly observable physical characteristics is to me pure BS. As planetary systems are discovered around other stars (and some already are starting to be visible with modern telescopes), the variety and magnitude of what might be considered a planets is going to be more diverse than could be thought of with such a heliocentric definition. The very notion that the only thing to be considered a planet must orbit the Sun (as the dominant mass of the orbital system) is already absurd. For that notion alone the IAU ought to take up the whole definition again but this time really consider the long term ramifications for other star systems in that definition too.... or perhaps they aren't called "planets" when they orbit a star other than our Sun?

I'm not too hung up on calling Pluto a "dwarf planet", as I think the definition really is quite appropriate. The issue is what else might fit that definition too. Perhaps even Charon ought to be considered a "dwarf planet" as well? The trick is if Pluto has a substantive atmosphere or if it is more airless like the Moon or the Galilean Moons of Jupiter. Hopefully the New Horizon spacecraft will put that question to rest for once and all, and perhaps show us a bit more in terms of what this astronomical object might be able to display when viewed up close.

Re:Pluto rules

[SEE]

Actually, it's part of the current IAU definition that a planet must no merely orbit a star, it must orbit the Sun itself.

Re:Pluto rules

[SEE]

So we will end up with objects that are in hyrdostatic equilibrium that are smaller in diameter / size than other objects that are not.

The former are massive enough to be planets, the latter are not.

I think you at a minimum need to add "and orbit around an object which is massive enough for fusion to occur"

Nope. The path of the orbit of Luna around the Sun is a fully convex shape. So clearly Luna is still a planet under that rule . . . unless you start adding a whole bunch of additional qualifications regarding dominating the orbit or barycenters. And you have the problem of bodies in interstellar space too small to fuse (sub-brown dwarfs, rogue planets) but which don't orbit any stars, except in the sense they orbit the galactic center of mass.

The only rule that avoids dozens of special clauses is to stick with mass. Luna, Ceres, Io, Pluto, Charon? Planets one and all.

That's no Asteroid

[DigiShaman]

It's a KE weapon to be used by some nation.

I'm sorry, you lost part of your city to an asteroid?! Damn, what are the odds of that happening. Nature sure does suck doesn't it.

Re:That's no Asteroid

[sconeu]

Stephen Baxter's Titan has an asteroid being used as a KE weapon.

Re:That's no Asteroid

[jkflying]

Neil Asher's 'Prador Moon' has an entire moon being used as a KE weapon...

Re:That's no Asteroid

[myowntrueself]

E E 'Doc' Smith 'Lensman' series has pairs of PLANETS being used as a KE weapon

So now someone cite a scifi example of a solar system or galaxy used as a weapon?

Re:That's no Asteroid

[MichaelSmith]

Niven and Pournelle were there first.

Re:That's no Asteroid

[MichaelSmith]

So now someone cite a scifi example of a solar system or galaxy used as a weapon?

E E 'Doc' Smith 'Lensman' series featured two galaxies colliding. Not sure if it was by design.

Re:That's no Asteroid

[Robert Zenz]

That depends, does using a giant ring around the sun to generate one hell of a laser count?

Main concept missing from summary

[iggymanz]

The asteroid orbits one of the two Lagrangian points of stability of the Earth-Sun system

Re:Main concept missing from summary

[tommy2tone]

The asteroid orbits one of the two Lagrangian points of stability of the Earth-Sun system

There are 5 Lagrange points. One on the other side of the sun, one on the other side of us, 1 ahead of earth in orbit, one behind earth in orbit, and one in between us and the sun.

Re:Main concept missing from summary

[ZombieBraintrust]

If there are only 5 then why did it take so long to find this rock? Is it becaue the sun is between us an it? If so then there could be some real intersting stuff at that lagrange point.

Re:Main concept missing from summary

[ZombieBraintrust]

Ahh read the article. The rock isn't at the lagrange point but rather orbits the lagrange point.

Re:Main concept missing from summary

[Anonymous Coward]

RTFA.

Re:Main concept missing from summary

[iggymanz]

But three of the Lagrange points are only stable in a plane perpendicular to the orbits of the two bodies making the point, they are not points of stable equilibrium for any displacement

Re:Main concept missing from summary

[Anonymous Coward]

Right, but only L4 and L5 are technically stable. L1 through L3 are only stable in one plane - I think they call it meta-stable. L4 and L5 will cause the object to "orbit" the point in a kidney shaped orbit. They never sit "at" the point as there is always some force to perturb them.

Re:Main concept missing from summary

[tommy2tone]

If there are only 5 then why did it take so long to find this rock? Is it becaue the sun is between us an it? If so then there could be some real intersting stuff at that lagrange point.

because the rock is 300 meters wide... space is a lot larger than that. Also the sun makes it difficult to see from the ground

Re:Main concept missing from summary

[Anonymous Coward]

There are 5 Lagrange points.

But they are not all stable, are they? As far as I recall, there are also some unstable.

Re:Main concept missing from summary

[camperdave]

Actually, the Sun would help because it would be illuminating the asteroid. It would be a permanently lit crescent in the morning sky.

Re:Main concept missing from summary

[Dthief]

yes, and only 2 are STABLE minima, the other 3 are unstable maxima

Re:Main concept missing from summary

[camperdave]

L1, L2, and L3 are all unstable (which is why I never understood the push to put a refuelling depot at Earth-Moon L2). Only L4 and L5 are stable.

Re:Main concept missing from summary

[Anonymous Coward]

L1, L2, and L3 are all unstable (which is why I never understood the push to put a refuelling depot at Earth-Moon L2).

Because it takes greatly reduced stationkeeping effort vs other orbits (where the moon causes perturbations) -- and even less if you go into a halo orbit instead of parking right at the L2. This means both less fuel used, and less time pressure on contingency missions if your stationkeeping thrusters or control system should be disabled.

Re:Main concept missing from summary

[camperdave]

But L4 and L5 are completely stable. No need for stationkeeping thrusters at all.

Re:Main concept missing from summary

[mister_playboy]

L2 is much closer to Earth than L4 or L5 is.

Re:Main concept missing from summary

[Anonymous Coward]

I don't think L2 is really what you had in mind.

Re:Main concept missing from summary

[tommy2tone]

yes but the sun would also give a glair on any ground-based telescopes...

Re:Main concept missing from summary

[camperdave]

yes but the sun would also give a glair on any ground-based telescopes...

Where would the Sun get egg whites?

If you mean glare, you'd be wrong. Astronomical darkness ends about an hour and a quarter before sunrise. This asteroid, because of its orbit, will rise precisely four hours before the sun. So you've got over 2.5 hours of dark in which it would be visible.

Re:Main concept missing from summary

[LeadSongDog]

L1, L2, and L3 are all unstable (which is why I never understood the push to put a refuelling depot at Earth-Moon L2). Only L4 and L5 are stable.

When you pull off the freeway for refuelling, you want to do it at the top of a hill, not the bottom: it wastes less energy (and reaction mass in our case). Yes, you have to stationkeep at the hilltop, but that's cheap in comparison. Question for the orbital mechanics in the house: what potential energy difference takes a kg from L5 up to L2 anyhow? "Inquiring minds want to know".

Re:Main concept missing from summary

[tommy2tone]

Where would the Sun get egg whites? If you mean glare, you'd be wrong.

Oops! Haha.

This asteroid, because of its orbit, will rise precisely four hours before the sun. So you've got over 2.5 hours of dark in which it would be visible.

This depends entirely on where you are in the world. And I restress that the asteroid is only 300 meters wide. It would still be difficult to see.

Re:Main concept missing from summary

[Anonymous Coward]

This is true, I don't know why some idiot moderator modded parent down.

I like the proposed names

[Bob the Super Hamste]

I like the proposed names of Coeus or Crius, the sons of Gaia for those who didn't RTFA, that that author suggests.

Re:I like the proposed names

[Anonymous Coward]

Given that it's a Trojan, I think Coitus might be a better choice.

Intriguing

[dastrike]

And here I thought that from what I've heard so far that Earth had possibly some dust or at most some gravel at its L4 and L5 points. This discovery of a sizable asteroid there makes the Earth's L4/L5 points much more interesting. Hopefully there is even more to be found!

Re:Intriguing

[tommy2tone]

I am surprised they haven't found this before. They are planning on installing satellites at L4 and L5, you would think they would figure out if there was anything there waiting on us.

Re:Intriguing

[Amouth]

well if you look at it's orbit it is orbiting the L4 in way that is out or our orbit plane.. so while it's stable it's also not exactly just sitting there.

When did it get there?

[Med-trump]

When did it get there?

Re:When did it get there?

[Dthief]

I bet it is a spy satellite placed by aliens to watch us from afar.....its also a good port to refuel when you want to go on a weekend anal-probing trip with the fam.

Re:When did it get there?

[Anonymous Coward]

Tuesday.

and what's "First Earth" ?!

[Thud457]

If it's a Trojan asteroid, does that mean it's full of space Greeks?!!!

Re:and what's "First Earth" ?!

[PlasmaEye]

What's scarier is that it could be full of space Spartans.

This is madness!
THIS. IS. SPAAAAAACE!

Re:and what's "First Earth" ?!

[Anonymous Coward]

Totin' that joke all over this place aren't ya? You're such a clever individual!

Re:and what's "First Earth" ?!

[Anonymous Coward]

Blasphemy! Madness!

Re:and what's "First Earth" ?!

[c0lo]

If it's a Trojan asteroid, does that mean it's full of space Greeks?!!!

No, it just means that Earth hasn't updated its antivirus (and, possibly, has a nasty habit of visiting promiscuous sites on the Internet).

Re:and what's "First Earth" ?!

[bursch-X]

If it's space greeks they could be dangerous being all broke and such, could turn them into space pirates

Re:and what's "First Earth" ?!

[Paul1969]

If it's a Trojan asteroid, does that mean it's full of space Greeks?!!!

Sigh. Try using your brain occasionally.
The Trojans were *not* Greeks. The Greeks were their enemies.
I guess the Brad Pitt movie didn't make that point clearly enough.

Re:and what's "First Earth" ?!

[Anonymous Coward]

Give us another 20 years or so and it'll probably be filled with Space Geeks at the very least. If they're from Greece, all the better!

Re:and what's "First Earth" ?!

[Zenaku]

I'm going to give you the benefit of the doubt and assume you aren't trolling:

A Trojan Asteroid would be full of Greeks in the same way that the Trojan Horse was full of Greeks.

Re:and what's "First Earth" ?!

[eriqk]

"The thing's hollow—it goes on forever—and—oh my God—it's full of Greeks!" --David Bowman

Re:and what's "First Earth" ?!

[Anonymous Coward]

In space no one can hear you scream.

maybe it trails

[VolciMaster]

how do we know it's "leading by 60 degrees"? Maybe it's trailing by 300!

Re:maybe it trails

[Anonymous Coward]

Or maybe the sun is rotating around us...

Re:maybe it trails

[digitig]

We and the sun are orbiting the common center of gravity. It's just that that common center of gravity is well inside the sun.

Re:maybe it trails

[PhxBlue]

In a word? Vectors.

Re:maybe it trails

[VolciMaster]

In a word? Vectors.

Whoosshh..

We know who to blame here

[Anonymous Coward]

Way to go Microsoft.

Now even asteroids are trojaned.

Re:We know who to blame here

[SnarfQuest]

Nope. It's caused by Global Warming, which is caused by man. Everything that happens, or doesn't happen, is caused by Global Warming.

Re:We know who to blame here

[peragrin]

even if it is a glacier which every 5,000-10,000 years builds itself up, and then melts away. repeating the process over and over again, in some form of cycle that is very hard to understand.

It's not a Trojan...

[Anonymous Coward]

It's an artificial monitoring station.

Run Away!!!

[SomewhatRandom]

Well, now, uh, Launcelot, Galahad and I, wait until nightfall, and then leap out of the asteroid, taking the French, uh, by suprise. Not only by suprise, but totally unarmed! ...*Who* leaps out?

Re:Run Away!!!

[berashith]

damnit. i came here just to make this joke.

Re:Run Away!!!

[SnarfQuest]

Well, then, go away. I need to se a man about some shrubbery.

Re:Run Away!!!

[berashith]

be sure to bring a herring with you. Never know if you'll need one.

Re:Run Away!!!

[Anonymous Coward]

is that a euphemism for your dealer?

Re:Run Away!!!

[Anonymous Coward]

Well, then, go away. I need to se a man about some shrubbery.

What about Bush?

sooo...

[Anonymous Coward]

So, would this be a job for TrojanMan?

Obligatory ZZ Top reference

[Anonymous Coward]

Rumour spreadin' a-'round in that Nerdy town
'bout that Rock inside La Grange
and you know what I'm talkin' about.
Just let me know if you wanna go
to that stone out on the range.
They got no friction out there ah.

Have mercy.
A haw, haw, haw, haw, a haw.
A haw, haw, haw.

Well, I hear it's fine if you got the time
and the TK7 to get yourself in.
A hmm, hmm.
And I hear it's tight most ev'ry night,
but now I might be mistaken.
hmm, hmm, hmm.

Ah have mercy.

Trojan Asteroid is that like a

[Anonymous Coward]

Trojan Asteroid is that like a prophylactic planet?

you must declassify

[Anonymous Coward]

it appears earth has not cleared its orbit of debris. you must declassify it as a planet now.

Cruithne

[Anonymous Coward]

Cruithne is still cooler.

Re:Cruithne

[niktemadur]

Thanks, I was trying to remember the name of that bad boy. Cruithne!
http://en.wikipedia.org/wiki/3753_Cruithne

Don't slow down

[sousoux]

In fact. Don't speed up either.

VLBI

[vlm]

Who will be the first person to suggest placing VLBI radio telescopes at each lagrange point? Oh I guess it'll be me. A nice heavy asteroid would be convenient for vibration dampening WRT antenna pointing.

The problem is when/if we ever do planetary colonization, those L points will be in high demand for planetary relay satellites, as no matter where any other planet is in its orbit relative to earth's orbit, at least one earth L point should be in view... so what do we want there, sensitive receivers or big ole transmitters? I'm guessing we'll have some kind of scientific "quiet hours" scheme where the scientists get the first second of every minute, first minute of every hour, and first hour of every day, of radio silence. Or maybe they'll just be screwed?

Re:VLBI

[Anonymous Coward]

The problem is when/if we ever do planetary colonization, those L points will be in high demand for planetary relay satellites, as no matter where any other planet is in its orbit relative to earth's orbit, at least one earth L point should be in view... so what do we want there, sensitive receivers or big ole transmitters?

One of each? Reserve L4 for comms, L5 for astronomy. An array of scopes at every planet's L5 would be an awesome VLBI array; even just 1 Earth and 1 Mars scope would exceed a pair of Earth scopes most of the time, Put your comm stations in orbits about the L4 that are perpendicular to the planet's orbital plane, and high enough to see over the sun most of the time. You've obviously got ground stations on most planets, these can fill in during the brief dropouts as your comm station experiences conjunctions _and_ is near the ecliptic.

Re:VLBI

[Anonymous Coward]

sorry.. The Corporation will not tolerate such blatant abuse of its property. Get back to work son, you need to fill your mining quota by the end of this work cycle..

Re:VLBI

[PhxBlue]

those L points will be in high demand for planetary relay satellites, as no matter where any other planet is in its orbit relative to earth's orbit, at least one earth L point should be in view... so what do we want there, sensitive receivers or big ole transmitters?

Or we could split them up: One Lagrange point for transmitters, one for receivers?

Re:VLBI

[NoNonAlphaCharsHere]

All the *radio* astronomy will be done from the "dark" side of the Moon, which will block the radio noise pollution from the Earth.

Re:VLBI

[Nethead]

Damn! Now I have an intense urge to put a 2m ham repeater at L4.

Re:VLBI

[Anonymous Coward]

This asteroid is in L4. For VLBI, L1 would do. L2 is inconveniently shadowed (i.e. no solar power) and L3 is on the other side of the sun, so no direct communication is possible. As PhxBlue noted, using L5 is another option. And finally, these are just Earth's Langrangian points. For solar-system-sized VLBI, we might as well use L4 and L5 of other planets. Mars conventiently has trojans in both, and a far bigger distance between them (i.e. longer baseline for VLBI)

Re:VLBI

[psydeshow]

Damn! Now I have an intense urge to put a 2m ham repeater at L4.

Hell, I have an intense urge to park a Winnebago at L4.

Gor.

[Anonymous Coward]

So they finally found Gor. John Norman wrote about it ages ago. http://en.wikipedia.org/wiki/Gor

Re:Gor.

[mlts]

If this were found at L3, that would sound about right.

Earth downgraded, no longer a planet

[Anonymous Coward]

Wasn't clearing it's orbit of other objects one of the conditions of being considered a planet that in part lead to Pluto being downgraded? I strictly mention this because I think the downgrade was silly. They seem to cherry pick conditions with the intent to downgrade Pluto.

Re:Earth downgraded, no longer a planet

[Anonymous Coward]

First: you're misinterpreting "clearing its orbit" -- while literally it certainly could be taken that way, it's actually a term of art with a specific, if implicit, meaning. It doesn't apply to small bodies under the primary's gravitational control. This includes moons (orbiting) as well as trojans (L4 and L5 points) and crossing bodies with orbital resonances. (As an interesting side note, AIUI the case of a double planet is a bit sketchy -- in a few million years when the Earth-Moon barycenter finally lies outside Earth, I guess they'll have to clarify...)

This is why Neptune is a planet even though Pluto (and other plutinos) cross its orbit -- they're under Neptune's control, locked in a 3:2 resonance.

As for the "silly" downgrade. Looking at the solar system, we can see there's several distinct classes of bodies visible:

1. Gaseous bodies large enough for stellar ignition (i.e. stars, namely Sol)
2. Gaseous bodies large enough to clear their orbit, but not large enough for stellar ignition (i.e. gas giants)
3. Rocky/icy bodies large enough to clear their orbit (i.e. terrestrial planets)
4. Rocky/icy bodies large enough to round themselves, but not to clear their own orbit (i.e. dwarf planets)
5. Rocky/icy bodies too small to round themselves (i.e. asteroids and comets)

These are drawn along natural lines -- we see clusters of objects in each group, and relatively few borderline cases. (Of course, we may be biased by the nature of our specific star system on some points, since exoplanetary astronomy is still in its infancy.)

Now our first division is based on what a body orbits -- the Jovian moons would surely qualify in group 3, but are not planets because they don't orbit the sun. IMO this is more than a bit weird, but it's a long-standing convention which the ITU doesn't want to shake up.
But with the proviso that we exclude bodies not orbiting the sun, we've got this term "planet" -- what should it's definition be?7

• [23] -- Includes the classical planets, Urectum and Neptune, but leaves out Pluto.
• [234] -- Plausible, but it means scores if not hundreds of planets -- notably including Ceres and Vesta, which we demoted way before Pluto was found. OTOH, it does keep Pluto, which we already called a planet.
• [2345] -- Ruled that one out a long time ago when we downgraded the handful of asteroids discovered at the time.

So the question is: demote only 1 planet, rolling back the most recent addition, and returning the set of planets to exactly what it was from 1846 to 1930? Or promote two asteroids, rolling back a decision (re: Ceres and Vesta) more than twice as old as Pluto's acceptance, changing the set of planets to something it's never been before, and including countless new bodies (including the newly discovered Eris, Haumea, Sedna, Orcus, Quaoar, Makemake, and some others without names or whose names I forgot)?

Neither approach is wrong per se, but I see the ITU's solution as slightly better, especially since orbit-clearing is fairly easy to determine from Earth, while hydrostatic equilibrium is much harder to establish (and IMO it's better that the uncertainties will be between asteroid/comet/SSSO and dwarf planet, rather than between planet and non-planet -- less butthurt over things being upgraded and downgraded that way). It's less change, it only changes recently classified things, and it reduces the odds of having to revise all our textbooks with a new planetary list each year unless and until we make a _significant_ new discovery. Basically the same reasons downgrading the asteroids was a good idea back in the 1800s -- or are you still feeling assraped by that decision, too? (BAAAAWWWWAAAAAAWWWAAAAAWWWWW! WHY DO YOU GUYS HATE CERES?!)

Now maybe you disagree -- maybe you'd rather (as, e.g. Alan Stern) class 2 & 3 as "uberplanets", 4 as "unterplanets" with the combined set of 2, 3, & 4 as "planets" -- which is sane enough. And you can certainly argue that ITU should have expli

Re:Earth downgraded, no longer a planet

[Anonymous Coward]

it's actually a term of art with a specific, if implicit, meaning.

Which is why using it as a metric to determine whether something is a planet or not sucks. The "goal of not having hundreds of planets" was silly from the start.

Re:Earth downgraded, no longer a planet

[Anonymous Coward]

it's actually a term of art with a specific, if implicit, meaning.

Which is why using it as a metric to determine whether something is a planet or not sucks.

Well, yes. The wording, without an explicit definition, sucks. Which says exactly nothing about the (non)suckage of the rule as actually implemented, using the actual implied definition.

The "goal of not having hundreds of planets" was silly from the start.

If you feel that way, fine.
But in that case, it's clear they didn't "cherry pick conditions with the intent to downgrade Pluto", they merely chose the same "silly" goal they'd had since the 1800s, of seeking to restrict "planet" to the handful of bodies with the greatest individual significance, rather than the much larger population of individually less-significant objects.

One, if it were true, would be a shocking (if totally inexplicable) ideological distortion of science to persecute one particular object. The other one, which is true, reflects the simple truth that not everyone will agree on how to extend and rigorize an old term with no precise definition.

Must be a bad communicator...

[Anonymous Coward]

TK7...why aren't you at your post???

A++ DENIAL. WOULD READ AGAIN.

[Anonymous Coward]

of course, the vast majority of scientists disagree, but that's probably also "very hard to understand" for you

no surprise really

[v1]

First thing that crossed through my mind when I read this, duuh, that's an L4 or L5 isn't it?

Probably the only reason it took them this long to "discover" it was its small size. After all, they knew exactly where to look.

Re:no surprise really

[Anonymous Coward]

No, go look for an animation of Jupiters trojans and you'll quickly realize, that the L4 and L5 "points" are quite huge areas.

Wait, wait, wait

[Roachie]

Tell me.... Does it have oil?????

Re:Wait, wait, wait

[c0lo]

Tell me.... Does it have oil?????

Yes, of snake variety. Wanna buy some?

Trojan? Trojan?

[LynnwoodRooster]

THIS IS SLASHDOT!

Get out there...

[kronnek]

... and find out what it is made of. Get some govt funding going to a private company and mine it. Profit.

Let's turn it into a space habitat

[Paul Fernhout]

http://visions2200.com/SpaceHabitat.html

Re:Let's turn it into a space habitat

[Anonymous Coward]

I'm with ya Paul. That was my first thought as well. When do we leave, and how do we get there?
-sticks out thumb-

There are additional moons to be found

[GPS Pilot]

I've always suspected that Earth has some additional tiny moons that haven't been discovered yet -- but my professors always pooh-poohed that idea, without really giving a good reason why.

Now it turns out that an Earth Trojan has gone undetected until now. This strengthens my belief that Earth has some miniature natural satellites awaiting discovery.

Re:There are additional moons to be found

[iggymanz]

Sorry but there are none now, early in the formation of the earth-moon system there would have been debris, but after a billion years would be either ejected or become part of earth or moon.

http://www.newscientist.com/article/dn13836-did-earth-once-have-multiple-moons.html

Funny that third stage of Apollo 12 was found orbiting as moon.

Re:There are additional moons to be found

[GPS Pilot]

Thanks, but your article is about objects that might have hung out at the Earth-Moon Lagrangian points. It neither supports nor disproves the idea of some plain old moons currently orbiting Earth, which are simply too small to have been discovered yet.

equilateral triangle?

[Garble Snarky]

Why is it 50 million miles away? If it's at a Lagrange point, at 60 degrees offset, shouldn't it be 93 million miles away?

Re:equilateral triangle?

[iggymanz]

It's *almost* an equilateral triangle, if the earth's mass were totally negligible then it would be perfect e. triangle. Don't forget the earth-sun distance varies too, in elliptical orbit case you get lagrange area rather than point you get with circle.

Re:equilateral triangle?

[iggymanz]

and meant to conclude with, the object is orbiting the lagrange area and not at it

Does this mean Earth is no longer a planet?

[C_Kode]

Does this mean Earth is no longer a planet like Pluto?

Planet requirements:
1. It needs to be in orbit around the Sun. (Check)
2. It needs to have enough gravity to pull itself into a spherical shape. (Check)
3. It needs to have “cleared the neighborhood” of its orbit. (Uh oh! Pluto doesn't satisfy this requirement and apparently now Earth doesn't either!)

Obviously I jest, but I do find it funny.

Re:Does this mean Earth is no longer a planet?

[Myopic]

Yes, jests are fun. But seriously, it would depend on how many decimal places before you agree to round up to "swept out". I think most people would be willing to round up in this case, but not in Pluto's.

Re:Does this mean Earth is no longer a planet?

[syousef]

That is because the IAU passed an IDIOTIC politically motivated definition defined by a committee of washed out has-been scientists, that made absolutely no sense neither scientifically nor in the lay vernacular.

By this definition
- no extra-solar planet is actually a planet, since they don't orbit the Sun (aka Sol, OUR star). Why they couldn't replace "sun" with "parent star" or "primary graviationally bound star" is beyond me.
- a dwarf planet is not a planet either. (They needed to use another name for what they called dwarf planet...but no lets make it sound like a subclass even though it's not)
- you need further explanation to say how spherical is spherical
- you need further explanation things like what "cleared out it's orbit" means

I HATE the definition. It's just gibberish and does no credit to the science of Astronomy.

Earth must be hung like a Roman god

[GodfatherofSoul]

300 meters across?

This was predicted in 1985

[Anonymous Coward]

http://en.wikipedia.org/wiki/Eon_(novel) anyone?

It's so big

[Bengie]

The Trojan asteroid now comes with a fire & ice sensation.

It Must Be Said

[Lotharus]

I for one welcome our new Trojan Earth Overlords!