A Planet That Orbits Its Star the Wrong Way 257
Smivs writes "BBC News is reporting that astronomers have discovered the first planet that orbits in the opposite direction to the spin of its star. Planets form out of the same swirling gas cloud that creates a star, so they are expected to orbit in the same direction that the star rotates. The new planet is thought to have been flung into its 'retrograde' orbit by a close encounter with either another planet or with a passing star. The work has been submitted to the Astrophysical Journal for publication. Co-author Coel Hellier, from Keele University in Staffordshire, UK, said planets with retrograde orbits were thought to be rare. 'With everything [in the star system] swirling around the same way and the star spinning the same way, you have to do quite a lot to it to make it go in the opposite direction.' Professor Hellier said a near-collision was probably responsible for this planet's unusual orbit. 'If you have a near-collision, then you'll have a large gravitational slingshot from that interaction,' he explained. 'This is the likeliest explanation. But it might be possible you can do it by gradually perturbing the orbit through the influence of a second planet. So far, we haven't found any evidence of a second planet there.'"
Maybe it was Kal-El? (Score:3, Funny)
You know, he has this thing about spinning planets the other way around...
Why do they blame the planet? (Score:5, Interesting)
Maybe the sun reversed its spin.
Re:Why do they blame the planet? (Score:4, Informative)
The star is not a likely cause for its abnormal rotation, although that would make it far more interesting.
Re:Why do they blame the planet? (Score:5, Insightful)
Car analogy (Score:2)
How does this happen? TFA is an article about a planet that has retrograde motion and someone manages to whip out a car analogy. And it even sort of makes sense. Well played, sir. Well played.
Re:Why do they blame the planet? (Score:5, Insightful)
You have little understanding of how science works and how scientists actually think. If you want to talk about cherished theories that can't be changed talk to creationists and theologians. If you want to talk about theories that explain and simulate the universe that are regularly changed, usually but not always gradually, learn the scientific method and about science.
I have been trained as a physicist and a scientist and the first lessons they begin teaching(besides calculus and the other basic courses) are that science is the process of curiosity, reason and doubt. It is a collaborative effort that is larger than any single person and it is a slow struggle where answering one question means opening up many many more. It is the process of expanding the universe by exploring the world around us and seeing how big, vast and wonderful our lives and this world really are.
Religion too often gives us the like of seven days, 6000 years and a wet ball of mud to live on, with harps and clouds if you've been good afterward. Its comforting but it is small.
Re:Why do they blame the planet? (Score:2)
It's not even comforting. I hate the sound of harps, considering to spend eternity listen to that junk... What was that qualification list again to avoid it? Lie, steal, cheat and listen to heavy metal music?
Re:Why do they blame the planet? (Score:3, Insightful)
You haven't had too many good discussions with Theologians, have you?
Theology and science are sibling disciplines, addressing different issues. You find lots of curiosity, reason and doubt in both.
Seven days, 6k years, etc. aren't theology. I agree entirely with your conclusion there. These kind of small, restrictive ideas come from the same kind of (selective) mindlessness that you can often find in militant atheism.
I agree with your response to the GP, for the record.
Re:Why do they blame the planet? (Score:3, Insightful)
Religion too often gives us the like of seven days, 6000 years and a wet ball of mud to live on, with harps and clouds if you've been good afterward.
Of course religion doesn't give you a wet ball of mud. It gives you a wet flat plane of mud, with water above it (read Genesis).
Re:Why do they blame the planet? (Score:4, Insightful)
The "dust cloud" theory only states that the majority of planets should rotate with their sun. There are a number of known mechanisms, some discusses in TFA, which can produce retrograde motion. We have several moons in the solar system showing retrograde motion. So this does absolutely nothing to disturb current theories of planet formation - you would have to find dozens of these to do that. It just appears that, in this case, one of several interesting events must have happened, and it might be worth looking for evidence of such an event. For example, if it were a near collision, it would be worth backtracking the paths of nearby stars to see if they were candidates for this decision.
This is not a "the current rules are broken" announcement, but a "hey, something interesting" announcement.
Re:Why do they blame the planet? (Score:2)
Re:Why do they blame the planet? (Score:2)
Re:Why do they blame the planet? (Score:5, Insightful)
Depends on what gets perturbed, I guess.
Try not to think just in two dimensions. Imagine the orbit as a very large ring. Instead of thinking of it shrinking, imagine the ring pivoting out of the usual orbital plane. Imagine this ring slowly rotating. Eventually, it'll settle back to the plane yet the planet will be orbiting backwards relative the the original and the star's rotation.
Re:Why do they blame the planet? (Score:3, Insightful)
Wow, what a free-your-mind moment I had reading that.
A similar scenario could be that the sun somehow turned upside down. Maybe the sun spins in two dimensions: around the expected axis perpendicular to the orbital plane, and also an axis parallel to the orbital plane.
Re:Why do they blame the planet? (Score:2)
I'm curious if the gravity well of the new local sun will eventually slow it's backwards orbit down and reverse it at some point or if it will end up like our moon in a locked orbit that never changes the side facing the planet? It's theorized that a black hole will actually drag the space time around it in the direction of it's spin. You would think that even a miniscule gravity well from a sun (comparatively speaking) would do the same to space-time and end up dragging the orbital momentum of the planet down to the point that it either slows it's retrograde orbit or starts orbiting in the proper direction (thinking in scales of billions of years).
I've even seen theories about Venus that are in a similar vein due to the fact that it's orbital rotation is actually backwards from the typical counter-clockwise rotation that all of our solar system planets follow. I'm not suggesting that it was 'captured' from a passing star, but perhaps it fell from farther out in our solar system and was 'captured' in the inner system in a similar way?
Re:Why do they blame the planet? (Score:5, Funny)
Sun's don't go both ways. They're all either straight or gay.
Re:Why do they blame the planet? (Score:5, Funny)
Sun's don't go both ways. They're all either straight or gay.
Maybe, but who's to say it can't be turned? It's orbital ring got invaded by a foreign object. Maybe this particular sun, you know, liked the experience?
Re:Why do they blame the planet? (Score:2)
I wonder if that would be possible if the planet's star collided with a second star, which could have inverted the original momentum.
Re:Why do they blame the planet? (Score:3, Insightful)
Could this perhaps been the effect of another star passing nearby and changing the axis of the star rather than flipping the orbit of the planet?
Re:Why do they blame the planet? (Score:2)
I would suspect (without bothering with any math) that the energy required to reverse the spin on the star would be much larger than to set the planet orbiting backwards.
Hence the planet changing orbits is more likely.
Re:Why do they blame the planet? (Score:2)
How about the energy required for the big bang versus no big bang? Which is more likely then?
Re:Why do they blame the planet? (Score:2)
Re:Why do they blame the planet? (Score:2)
Conservation of angular momentum.
Maybe its in the southern hemisphere of that star? (Score:5, Funny)
Re:Maybe its in the southern hemisphere of that st (Score:4, Funny)
You mean its an Australian planet, mate?
Re:Maybe its in the southern hemisphere of that st (Score:2)
How do they know which way the star spins? Are they just assuming it is spinning in the same direction as its orbit around the galaxy? Why can't the entire system be retrograde?
I suppose since they can detect the direction the planet orbits, they can measure the blue shift and red shift of the advancing and receding sides of the spinning star, and know that way.
which left? (Score:2, Funny)
Re:which left? (Score:4, Funny)
Right
Poor Planet (Score:5, Funny)
Re:Poor Planet (Score:5, Funny)
Re:Poor Planet (Score:2)
Nobody move!
Re:Poor Planet (Score:2)
Re:Poor Planet (Score:2)
All the other planets keep pointing and saying "You're doing it wrong!"
To which it keeps replying,"G'day mate."
Re:Poor Planet (Score:2)
All the other planets keep pointing and saying "You're doing it wrong!"
That's what folks always say about us lefthanders. And then you wonder why we're perturbed!
Re:Poor Planet (Score:2)
All the other planets keep pointing and saying "You're doing it wrong!"
One of these things is not like the others,
One of these things just doesn't belong,
Can you tell which thing is not like the others
By the time I finish my song?
I'm no astrophysicist... (Score:2, Interesting)
but wouldn't this type of retrograde orbit be possible if the planet had gone "rouge" from it's original system and was then captured in the gravity well of its current parent star?
Re:I'm no astrophysicist... (Score:2)
This is exactly what I was thinking. A rouge planet could have been knocked out of orbit from a weak star and captured by this no star. The direction the star rotates wouldn't impact the captured planets orbit, the only important factor would be the mass of the star and if it was enough to capture the planet at the planets nearest approach.
Re:I'm no astrophysicist... (Score:5, Funny)
A rouge planet
What does Mars have to do with this?
Re:I'm no astrophysicist... (Score:2)
This is part of the argument as to why Pluto isn't a planet; it doesn't rotate in the same plane as all the other planets and sun's spin. So it's likely that it wasn't formed along with the rest of the solar system. Of course, if a planet can rotate backwards due to some close encounter with another object, I guess Pluto's orbit could have been knocked about too.
Re:I'm no astrophysicist... (Score:4, Informative)
Re:I'm no astrophysicist... (Score:2)
like my ex used to cake on.
Is she hot and still single? :P
And to think I was going to use the EVER-CLASSY "Can I have your stuff?" line...
Re:I'm no astrophysicist... (Score:5, Funny)
"But it might be possible... (Score:5, Interesting)
But, if it were to happen slowly, doesn't that imply that at some point it has a minimal orbital speed (if that's the correct term), and would fall right in? Seems to me that if it reversed direction, it must have been a relatively quick event. Unless, perhaps, the planet ends up being sent away from the star, and is then recaptured in a retrograde orbit. But, that's still not a "gradual perturbation."
Re:"But it might be possible... (Score:5, Insightful)
Er, no. The idea is that the inclination of the orbit keeps getting larger until the planet is orbiting "backwards." The planet doesn't stop and reverse its orbit.
Cheers,
Dave
Odd, then... (Score:2)
Finally, the article explains how they can tell which direction the planet crosses the star, but how do you tell which way the star is rotating?
Re:Odd, then... (Score:2, Insightful)
I also wonder if the planet suffers more collisions than it would otherwise.
Re:Odd, then... (Score:3, Informative)
Nope. It would just take one swift hit normal to the plane of the ecliptic to cause the angle of inclination to steadily change until it was revolving backward. However, the inclination may still be changing for all I know.
Nope. Each swift hit (delta-momentum) results in a single orbit change. A hit normal to the ecliptic is the most efficient in terms of angle-of-inclination change, but it does not cause a continuing inclination change.
Re:"But it might be possible... (Score:5, Insightful)
To put this in analogy form:
Picture someone making a pizza, when they spin it and throw it up in the air it lands spinning the same way. But if the pizza flips over in mid-air the rotation will be reversed when it lands but it didn't have to stop and reverse direction to do it.
Oh, and somehow a car is involved.
Re:"But it might be possible... (Score:5, Informative)
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Re:"But it might be possible... (Score:5, Interesting)
In this case, it's really the angle of the orbit that would be perturbed. Eventually it would be orbiting above and below the north and south poles of the star, and then perturbed even further until it was rotating the wrong direction. In that sense, it's actually orbiting in the correct direction, just offset 180degrees.
A similar explanation is often used to describe the fact that Uranus rotates clockwise, whereas all the other planets in our solar system rotate counter-clockwise. (Note, rotation != revolution. Rotation == spin, revolution = orbit). Effectively, virtually all the angular momentum of any given solar system is in the same direction. The odd object's motion may be twisted into appearing the wrong way by some dramatic celestial event.
Re:"But it might be possible... (Score:4, Informative)
A similar explanation is often used to describe the fact that Uranus rotates clockwise...
Er, Venus I mean. Uranus is slightly stranger...
Re:"But it might be possible... (Score:2, Funny)
"...you can do it by gradually perturbing the orbit through the influence of a second planet" claims the article.
Even if I had a second planet, I could probably figure out waaay more productive things to do with it than piss off the orbit of my first planet. That kind of puerile use of a natural resource on such a massive scale would probably only serve to perpetuate the vicious cycle of interplanetary-domestic-violence that has ruined so many healthy, loving solar systems. On behalf of Solar Family Therapists everywhere I'm ashamed that this Prof. Hellier condones such a flagrant misuse of such a precious resource.
Re:"But it might be possible... (Score:3, Informative)
In a 2 dimensional universe, yes. In this one? No. It implies that the plane of the orbit rotates through 180 degrees much like (here it comes everyone) a car tyre when you do a U-turn. It keeps rotating but eventually ends up going the other way.
Re:"But it might be possible... (Score:2)
If this were a movie then Mr. Spock would say that your pattern indicates two dimensional thinking.
Then, Captain Kirk would pound you in the butt in a totally heterosexual way with photon torpedoes.
I think it's a good thing that we aren't in a movie.
I know this one! (Score:2)
Maybe the planet's not native to that star. (Score:2)
IIRC, our solar system was not original part of the Milky Way, but was from some smaller dwarf galaxy that got absorbed into it. There could have been a parallel here which might be easier to explain it.
Opposite spin (Score:5, Informative)
were thought to be rare? (Score:4, Insightful)
Since this is the only one that's been found, I'd say that planets with retrograde orbits are still thought to be rare.
Re:were thought to be rare? (Score:5, Insightful)
There have only been a few hundred extra-solar planets found, so finding one that has a retrograde orbit is surprising if they were thought to be much less probable than 0.5% or so.
It all depends on the meaning of "rare", which is one of those innumerate words we ought to be doing without.
You insensitive clods! (Score:4, Insightful)
Axial Tilt? (Score:3, Insightful)
How about (Score:2)
the planet wasn't spawned by that particular star? Maybe it's a capture. I would imagine that a capture doesn't have to go with the spin, or against the spin - it could orbit from pole to pole.
Phhhht. I should have been an astronomer, huh?
Re:How about (Score:2)
(And by the way, I think if a planet's axis made a radical change, the poles would change as well. But I'm not sure.)
Re:How about (Score:2)
But - what if the planet weren't intact yet, when the capture was made? Two stars passing close together, one or both capture some of the matter swirling around the other star. It's still hot and gaseous, but orbiting in the opposite direction. Only later does it cool, coalesce, and eventually form a planet. I suppose it's more likely that an older star stole the matter from a young star - if they were both young stars, the captured matter would have been more likely to have met resistance, and eventually been forced into a more conventional orbit.
You are going to Kill Someone...... (Score:5, Funny)
This evokes that scene from "Trains Planes and Automobiles"......
Re:You are going to Kill Someone...... (Score:2)
Thanks for the laugh. That is one of my all-time favorite comedy scenes. I laugh every time I think of it.
Gradual Perturbation (Score:2)
But it might be possible you can do it by gradually perturbing the orbit through the influence of a second planet. So far, we haven't found any evidence of a second planet there.
Wouldn't a slowly perturbed planet fall into it's star once it reached stand still or near to it? Or maybe it was perturbed while way out far from the star, and then managed to reverse and miss the star as it fell towards it, and somehow got a near circular orbit again. I'd like to see what the path for a theoretical gradual perturbation and orbit reversal would look like.
Is it really a planet? (Score:2, Funny)
It's obvious. (Score:2)
I'm not entirely sure how, but I know global warming is involved in some way.
IIRC, sun is also a star... (Score:2)
... can't we send Superman to make it spin the other way to have normal time and not going back in time? :P
Red Dwarf (Score:2)
Did you feel that? (Score:2)
Did you feel that tremor? It was from millions of astrologist/astrology "practitioners" shuddering at the thought of a planet's permanent retrograde status!
Another possibility (Score:4, Interesting)
Another possibility is that the planet does not originate from the star it is orbiting. For example, the planet may have been in an unstable orbit around star 'A' and eventually escaped from star 'A' it traveled through space until it was caught in the gravitation of star 'B' and began to orbit. The orbit of the planet around star 'B' would be based more on the direction and angle it approached star 'B' as opposed to the spin of star 'B'
Just my theory.
Dumb earthlings.. (Score:2, Funny)
Second one found! (Score:2, Informative)
"Thought To Be Rare" (Score:2)
Yup, a pretty silly statement when the observation was of the first one discovered.
Still a silly statement after the second one discovered, the very next day:
http://www.newscientist.com/article/dn17613-second-backwards-planet-found-a-day-after-the-first.html [newscientist.com]
Re:Losing it's luster (Score:2)
Speak for yourself. This has been on my mind since I read about it this morning.
There is just so many possibilities and, for me, each one is amazing.
But don't worry. It's football season!
Re:Losing it's luster (Score:2)
I wonder how long until we figure out a way to detect inhabited planets. Can't be too far off.
They're already working on that; I read something recently about a probe that they're testing on Earth right now (it's in space, looking at Earth as a control). It's later going to turn around and look at extrasolar planets for signs of things important to life.
However, we're still unable to detect Earth-size planets in other star systems, as most of the planets we've detected are Jupiter-sized or more, but they are detecting progressively smaller planets.
Re:Losing it's luster (Score:4, Informative)
They're already working on that; I read something recently about a probe that they're testing on Earth right now (it's in space, looking at Earth as a control).
I think you mean the LCROSS Spacecraft [slashdot.org]
Re:Losing it's luster (Score:2)
Yep, that's the one. Thanks for that.
I especially liked the first comment about a false negative (for life) because of being over Detroit, and the reply who corrected him saying Detroit is full of rats and cockroaches.
Re:Losing it's luster (Score:2)
Re:Losing it's luster (Score:2, Insightful)
Re:Losing it's luster (Score:2)
I believe its exact words were 'Mostly harmless.'
And to answer the other question, when you flush, the water not only spins the other way, it comes out after YOU, not out of sight.
Re:Losing it's luster (Score:2)
Re:Losing it's luster (Score:5, Informative)
However, we're still unable to detect Earth-size planets in other star systems, as most of the planets we've detected are Jupiter-sized or more, but they are detecting progressively smaller planets.
You're a bit behind on that. Planets that are well within one order of magnitude of the size of Earth have been discovered. This one [slashdot.org] may be less than twice the size of Earth.
Re:Losing it's luster (Score:5, Informative)
why do you slashfucks keep using this order of magnitude shit even when it doesn't apply? do you really think it makes you look smart? orders of magnitude are used in a very specific fashion that even a 2nd grader can understand but you guys keep throwing it out there like it's a generalization. it's fucking not.
What's wrong with what he said? He said planets within an order of magnitude have been found. That means planets up to ten times as massive as the earth or as small as on tenth of the earth. He then points to an example where the planet is estimated to be half the size of earth.
Maybe you should brush up on simple 2nd grade mathematics principles before taking a pitchfork out and lighting that flaming brand?
As for a generalization, it can very well be one. It compares like objects within a scale that doesn't require any other measurements. You can say that one object is 2 magnitudes bigger than another if it is 100 times the size. You don't need to measure either object in any units.
So either get used to us "slashfucks" using scientifically agreed to and mathematically correct statements even if you don't understand them, or well, feel free to go find a site more suited to your level. Perhaps something with lolcatz or photos and a rating system?
Re:Losing it's luster (Score:5, Interesting)
I was looking at the stars one evening and the thought occurred to me that every star harbors a hideous mess; an immense collection of orbiting debris ranging from bloated gas giants with dozens of exotic moons to mangled chunks of gold weighing billions of tons. Those nice neat little points of light are actually solar systems, every bit as rich and complex as our own. Life, at least in primitive forms, is probably a common afterthought.
Think about the planet you're on now. Everything beyond iron is the shrapnel of stellar detonations coalesced and melted into a ball of metal orbiting the sun. Staggering quantities of baryons mushed together in weird configurations, colliding, erupting and aging for billions of years. Somewhere there is a near perfect sphere of nickel weighing five Earths and orbiting a black hole. It will be destroyed next week when it collides with and vanishes forever into the guts of an 9 billion year old brown dwarf. It will have never been observed by anything more sentient than a dusty comet.
When you really think about it the universe is creepy.
Extrasolar astronomy requires extraordinary equipment. We need to build more of it and figure out what the universe looks like below cosmological scales because we haven't got the first clue what's really out there. Humans were simply not endowed by nature with sufficient imagination to anticipate more than a small fraction of all the crazy shit we're going to find.
Re:Losing it's luster (Score:2, Insightful)
Re:Losing it's luster (Score:2)
Water exists only on our planet (no direct evidence it exists anywhere else, especially right now, in the Universe) and it allows us to survive
http://www.newscientist.com/article/mg19426065.400 [slashdot.org]
Re:Losing it's luster (Score:2)
lols, I was thinking what in ze hell? Excuse the pun. But what are the Russian drinking on the space station? Or is the LEO a part of our planet too?
.
It's funny how we like to categorize things. This planet, that planet, we're here, you're there, I am Chinese, you're Haitian. I am standing on "this" planet. To me, there is no planet. There is this space that we ALL live in.
Re:Losing it's luster (Score:4, Insightful)
Well, maybe you were amazed. The existence of extra-solar planets has never been in serious doubt; we went a long time without finding any for the simple reason that they are extremely hard to detect. There were many supposed observations that fizzled out in experimental error, and that resulted in a lot of skepticism being attached to further finds. Now that we have the proper measurement techniques, the discoveries are coming at a rate of a dozen or more per year.
Look at it this way. Suppose you and I are standing on two mountaintops a few miles apart on a dark moonless night. I have a five-cell flashlight and one of those war-surplus searchlights they use to advertise new furniture stores. If I point the flashlight at you and turn it on, you'll see it easily.
Now suppose I point the searchlight at you and turn it on. Then I turn the flashlight on again -- or maybe I don't. Can you tell whether it's on or not?
That is approximately the problem involved in finding an extrasolar planet.
rj
Re:Captured object? (Score:2)
While it is possible, it would probably be extremely unlikely. The odds are pretty slim for a planet to be stripped from one star and then captured again by another star. Space is just too damn empty, on average there is only 1 star per cubic parsec and the orbit of earth is 1/206625 pc.
Interactions with other giant planets in the system are probably the most likely explanation as they talk about in the article. Three-body interactions can have pretty crazy outcomes, astrophysically and for life in general :)
Re:Captured object? (Score:3, Interesting)
How about a direct capture, from an near-encounter with another star? That is, similar to the explanation in TFA, except that the planet originally belonged to the other star.
Re:Lets ask Dr. Pauli (Score:2, Informative)
Re:Not the first (Score:5, Informative)
Re:Not the first (Score:2)
Pluto is a Kuiper belt object anyhow. Objects that small in the vicinity of gas giants can get tossed into all sorts of orbits -- inclined, retrograde, highly elliptical -- but it would take quite a slingshot effect to get a large rocky planet or a gas giant going "the wrong way".
One way I can imagine a smaller object getting that way is if it never really reverses direction, the inclination just keeps increasing until it actually crosses perpendicular to the plane of the planets. Eventually it could get back into a fairly normal inclination but going backward because it has wrapped around. Again I can't see this working with a large planet -- once inclined, it would probably just stay that way since whatever large mass flung it out in the first place is now too far away to continue tilting it.
I wouldn't be all that amazed if it turns out the planet was a wanderer that got captured, and it isn't native to that solar system.
Mal-2
Re:Not the first (Score:2)
Pluto has a retarded orbit (no, that's not a scientific term)
Actually it is. Well, kind of:
Orbits Using Retarded Fields
http://authors.aps.org/eprint/files/1997/Jul/aps1997jul09_006/main.html [aps.org]
An economical semi-analytical orbit theory for retarded satellite motion about an oblate planet
http://adsabs.harvard.edu/abs/1980fmet.sympQ....G [harvard.edu]
and I would not be too far from correct terminology in saying that Earth's orbit is degenerate in the plane of Mars' orbit, no?
Re:Not the first (Score:2)
Re:possibly more simple explanation (Score:2)
Re:Important question... (Score:2)
Do toilet flushes swirl in the opposite direction on this planet?
What? Up?