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A 10th Planet in Our Solar System? 218

Apuleius writes "Here's a BBC story about a planet that may be orbiting the sun at 30,000 AU (Pluto's at 30 AU)...." This new wanderer, which may not have been created during the original formation of our system, according to the story, orbits the Sun backwards compared to the other planets. There's one in every crowd, isn't there?
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A 10th Planet in Our Solar System?

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  • by Anonymous Coward
    I don't know for sure, but isn't the orbiting period related to the distance to the sun? What would be the orbiting time for this 'planet'? bye, pieter
  • The book was "The 12th Planet" by Zecharia Sitchin. As to his educational background from his website (www.sitchin.com):

    "Zecharia Sitchin is one of a small number of scholars who can read the Sumerian clay tablets which trace Earth's and human events to the earliest times. He was born in Russia and raised in Palestine, where he acquired a profound knowledge of modern and ancient Hebrew and of other Semitic and European languages, the Old Testament, and the history and archaeology of the Near East. He graduated from the University of London, majoring in Economic History, having attended the London School of Economics and Political Science.

    Sitchin is a member of the American Association for the Advancement of Science, the American Oriental Society, the Middle East Studies Association of North America, and the Israel Exploration Society."

    Sitchin has written five books including "The 12th Planet" about the influences of 'extraterrestrial gods' on our civilization.
  • by Anonymous Coward
    Yeah I've heard a couple times about the discovery of planets past Pluto. Assumably, these were just found out to be wrong a bit later. My question is this: is there a groovy website that details the Planet X false alarms? ... Thanks!
  • it says it's
    "three billion billion miles" from the sun,

    "30,000 times more distant from the Sun than the Earth, putting it a significant fraction of the distance to the nearest star"

    so that's 3e18 miles, or 30,000 times 1e14 miles-to-Earth, which means at 1.86e5 miles per second, light would take 5.37e8 seconds to get to Earth, when in fact earth is eight light-minutes from the Sun, or about 4.8e2 light-seconds, so their [the BBC's] math does not sound right !!

    if we attack it a different way, 30,000 times 8 light-minutes is 24,000 light-minutes, or 400 light-hours, or 16.7 light days, which is only a bit over 1% of the way to Proxima Centauri, so this does not sound right either; it is hardly "a significant fraction of the distance to the nearest star"

  • by euroderf ( 47 )
  • If it is not exactly normal to the average ecliptic it will get pulled in to the average ecliptic plane. This will of course take and infinite amout of time. (This post is after working it out on the back of an envelope as is all good physics)
  • I believe the gravitational influence of the other planets would pull it into the ecliptic/the ecliptic up to it.
  • Yep. Originally, the Pluto-Charon system was noticed, and no-one could tell it was in fact two bodies. It was christened "Pluto", the 9th planet. When technology had improved and we were able to get a better look at it, it was noted there were two bodies. The larger of these is now called Pluto, the smaller Charon.

    Probably eventually it will be classified as a double planet system, if it is downgraded from planet status?

  • Dude, at a half light-year away you're talking some serious transit time. You might want to make this vacation part of a career change, or perhaps your retirement Grand Tour.

    When I retire, I don't plan on living my last millenia in this solar system, or even this galaxy. I plan on retiring to the Smal Magelenic Cloud. Of course, this would be after nanotech makes me almost immortal.

  • I don't know what kind of analyis was applied or what methods were used to come up with this, so I won't commment on that.

    What bothers me though, is that there are people who have been studying the orbits of comets for a very long time. People like Brian Marsdan at Harvard-CFA. Why hasn't Brian seen this sort of thing? He has access to a lots of data, a lot more than a mere 13 comets. It makes me wonder if this "discovery" may be nothing more than a selection effect (the 13 comets selected just happen to produce this sort of effect, but when you include a larger body of data, the phenomenon disappears).

  • Yes, and the b* have Episode 4, so you can't see how they were defeated.
  • You won't get much of a reaction without hydrogen - helium, at the heaviest. Jupiter is mostly heavy gasses (relatively speaking) and those aren't going to fuse in Jupiter's core.

    Even an object several times Jupiter's mass isn't going to do anything, if the atomic weights are too high. It takes the conditions inside a blue supergiant to get iron to undergo fusion, for example, and that reaction is unstable. (It takes more energy than it gives out.) Stars with iron in the core have a tendancy to splatter themselves over space in a supernova.

    Our own sun is capable of handling hydrogen, and some helium. Nothing heavier. Jupiter and Saturn are likely to have harbon cores - much heavier than helium and far too heavy for even a star of one solar mass.

    If this new planet, likewise, has a heavy core, it won't be capable of undergoing fusion, unless it's close to twice the mass of the sun. Something only two or three times the mass of Jupiter isn't even going to burp.

  • Damn!!! I was gonna post something like that.

    Guess we'll have to name the planet Mondos now :)
  • That's funny..I must BE from that planet....I've always eaten my corn on the cob vertically...

    go figure..

  • From the article:

    Being so far from the Sun - three thousand billion miles - it
    would take almost six million years to orbit it.

    "This would explain why it has not been found," explained Dr
    Murray to BBC News Online. "It would be faint and moving very
  • This is not all new, because there has been a theory called the "nemesis theory" which is an extension to the catastrophe theory. It states that there have been quite a lot of impacts on earth that more or less caused mass extinction. The impact that killed the dinosaurs is just one of them. Some scientists have found a strange cycle in those impacts of about 20 million years. They figured it must be caused by a small star, doubling with the sun. This sounds like more evidence for that theory.

  • Odd to here the news is from the BBC. Maybe Dr. Who was a documentary series...:-)
  • nearest star (Alpha Centauri) is 4.3 light years from earth, or: 4.3 * 365 * 24 * 60 * 60 * 186,000 miles (25,222,492,800,000). Planet "X" is 30,000 times more distant than earth from the sun (earth is 93,000,000 miles from the sun): 30,000 * 93,000,000 miles (2,790,000,000,000), so in this case 'a significant fraction' is approximately: .11061555343173692966, so I'd say the comment was pretty accurate.
  • But the new planet would be 30,000 times more distant from the Sun than the Earth, putting it a significant fraction of the distance to the nearest star.

    What does he mean by significant fraction?

    30000 Times the distance from the earth to the sun would be about 0.5 lightyear. The nearest star other than our sun is about 4.5 lightyears away.

    If there really is a massive planet orbiting the sun at half a lightyear away, there is no hope of ever sending a probe and taking pictures.
    • Light travels at 186,000 Miles per second.
    • Translation. Light travels at 669,600,000 Miles per hour.
    • Translation. Light travels at 16,070,400,000 Miles per day.
    • One AU (Astronomical Unit) is approximately the distance from the Sun to Earth. Or approximately 5 light minutes. 55,800,000 miles.
    • 30,000 AU is approximately 1,674,000,000,000 miles.
    • 30,000 AU/1 Light Day. (1,674,000,000,000/16070400000=104.16~)
    • So a ONE WAY trip at the speed of light would take approximately 104 days 4 hours. A round trip would be another 104 days and 4 hours. Now assuming that Fiber connections can actually push data at light speed, it'd take 208 days, 8 hours for the round trip, plus a couple seconds for the server to respond to the 1/3 of a year old request.
    • What IS the timeout period for IIP? (Interstellar IP)

    Chas - The one, the only.
    THANK GOD!!!
  • Oh the horror. Proof that shub-internet actually exists, if one thinks even for a moment. I can't believe people are worried about Y2K or the New World Order when there are crawling cthuloid horrors like this running and bleeping and bleating and croaking along our networks right among the more mundane packets of daily email, slashdot posts and Britney Spears mp3's.

    At one time I had some hope but better, far better, to live in shameful ignorance than even take slight cognizance of the sanity depriving crawling chaos. Take comfort that the Pope is sanctioning new internet saints and that scientists are the ones responsible for this discovery. Yeah, right.

    Say what you want, but when these subterranean horrors meet up with their elders .... I mean, it's not what they done, but what they're a goin' to do.

  • you saw a gorgeous female on bbc? impossible
  • This may not be a planet.... Do any astronomers reading Slashdot know if 30,000AU would qualify this as a planet via Bode's Law? If it is, wouldn't there be other objects between it and the Sun? It may be a moon that was sent into this retro orbit by some collision, as it is believed of Pluto.

    Linux- Viva La Revolution!
  • Why bother going there? Why not just get a bigass telescope and look at it? It's not like there'd be any life there or anything.
  • Slightly off-topic: Isaac Asimov wrote novel called "Nemesis" that I thought was one of his better books.
  • There have always been different stories for Planet 'X', most of then disappeared when the Kuiper Belt started to be discovered. There was a story with Pioneer 10 earlier this year which had it suffering orbital peturbations from KB objects.

    If it does exists, it's too far away for a probe with current technology.

    I suppose they will call it Prosperine (Pluto's wife) as that appears to be widely used in SF for a tenth planet.
  • Or is it one of the others?
    Or have I taken leave of my senses completely?
  • There is mention of a "massive" object, but no mention of its estimated mass. Given that Pluto may be de-regulated from its status as a planet (has anyone heard the results of this?) due to its insignifigant size and mass, is it fair to speculate on the existance of this as another planet?

    Of course, if this object is massive enough to divert the course of comets then I suppose it is reasonable to assume that it would qualify as massive enough to factor as a planet...

    Its nothing but pure speculation at this point, but that does not prevent it from being fascinating.
  • I just lent the book out, but Carl Sagan utterly destroyed this argument in the book Broca's Brain.
    -Chapter on the paradoxers.

    (Don't mean to rain on your parade :)
  • Now that we may have found Alvin how long do you think it'l be before we find Dave?

  • Charon I think it is.

    The Moon and Earth are a binary planetary system too, it's only there's a greater mass difference and, well, a slight difference in materials and hence living conditions.
  • I thought that the question of Pluto as a planet was really more of the question of its origins and its composition than its mass.

    Off memory I think one theory is it came from a big asteroid belt orbiting our solar system a lot further out, but don't quote me on that.

    There's really no definition of a planet to my knowledge, it's more of a touchy feely thing, and that's the reason you get holy ways among astronomers about Pluto. =)
  • Yeah, the Oort cloud, that's the asteroid belt, that's it, maybe I should read the article first. =)
  • Pluto has always been considered a boarder-line minor planet. A Minor planet is basicly something the size of a small moon or large asteroid orbiting in our solar system. They don't tell the mass, so I assume that this is just what it is, a minor planet. There are a lot of minor planets out there, so this guy finding one would not be that much of a break through. Pluto is only famous because it was found a long time ago and became famous (1930's I think). The technique this astronomer used to find it is cool, its been done before to find planets exterior to our solar system through.
  • IIRC the technical definition of a planet is anything that orbits the sun. So if I threw a baseball into orbit around the sun by that definition it would be a planet. As far as classifying things as planets as we know them I don't think there is a definition. Look at the controversy over pluto for example. I think basically it comes down to size. If it's small it's an asteroid, if it's big, it's a planet.
  • If you read the article you would see that they give the size to be several times that of jupiter. Jupiter happens to be the largest planet in our solar system. Now if you rule out this new thing as a "minor planet" I hate to think what you would consider earth.
  • i remember a story on /. claiming that scientists had decided that Pluto was not a true planet. Wouldn't that make this the 9th planet?
  • I claim my 10 points, and humbly point out that someone cracked that one higher in the thread. nb, I think you got the spelling correct.
    Was that the one where Adric bought the farm?
  • Well, basically you don't. There's gravity, or you can throw away 3/4 of your sail, and have a laser reflect off it to push at you, but in low light conditions, the sail doesn't do much for you.
  • Yeah, but
    a) you can only work the deceleration trick once, since you need to throw away most of your sail to work it
    b) you need a looong time to stop, since the efficiency for stopping is much less (probably about 1/4) the efficiency for ordinary thrust at the same distance.
  • Check out project Orion, in the '50s or '60. The idea is to make LOTS of small atom bombs, and explode them behind the ship. Of course you need a rather sturdy construction for the ship, but you can get a pretty good acceleration, as long as nobody needs to get anywhere near the path of flight or the hind end of the ship.

    Sounds like a good use for some old stockpiles of stuff that's just begging for some way to throw it away, doesn't it?
  • Watch out, its Mondas, and its crawling with Cybermen! Just you wait, they're going to invade us in 1988 and...uh, whoops, wrong universe! *Dives into the TARDIS*
  • I, too, have some doubts about the newest candidate for Planet X... However, I want to answer/clarify some of your points.

    1) IMO, 13 points is not statistically significant. However, for all 13 orbits to be altered in the same way is somewhat remarkable.

    2) AFAIK, Jupiter has no nuclear reaction within it's core. The critical mass to begin nuclear fusion is 10-100 times that of Jupiter. If "Planet X" is only a few times more massive than Jupiter, it would certainly have a higher core temperature, but not necessarily high enough to fuse hydrogen.

    3) The "observations" of brown dwarfs has been solely through their gravitational effect on companion stars rather than direct optical observations.

    4) You are correct about the orbit. Without some observation of the objects trajectory, there is no way to know if it is elliptical (bound to the Sun) or hyperbolic (not bound).

    Looks like it will be an interesting read nonetheless.


  • Well, if it is 30,000 AU from the Sun, it would be approximately 10% of the distance to Proxima Centauri. That star is about 1.25 parsecs away, and 1 pc == 206025 AU.

    It's not all that significant in some respects, but if it is bound to the Sun, it certainly is interesting.

  • by MoToMo ( 17253 )
    We should name it Ork!
  • The BBC article mentioned that the object might lie in the constellation Delphinus. Although Delphinus is not far away from the ecliptic, Delphinus is not an ecliptic or zodiac constellation.

    The ecliptic is defined as the plane of the Earth's orbit around the sun, and the zodiac is defined as the zone within 7 degrees of the ecliptic, roughly corresponding to Mercury's orbital inclination.

    There is nothing about the ecliptic that makes it certain that all undiscovered hypothetical planets must lie within it. Pluto's orbital inclination is about 17 degrees, and it is not uncommon for comets to have highly inclined orbits. Our Northern Hemisphere friends were fortunate in that two bright comets (Hale-Bopp, Hayutake) passed really close to the North Celestial Pole recently.

    One thing to note is that Pluto and comets are relatively distant members of the Solar System. They would feel less of a gravitational influence from other planets such as Jupiter than inner planets. It therefore makes sense that a hypothetical distant planet, particularly if captured and half a light-year away, would only be in the ecliptic by chance, and not because of any immutable cosmic law.
  • There's a couple of reasons why this proposed planet is harder to detect than some of the planets outside the solar system:
    • The planets detected outside the solar system are all close to their parent stars. To confirm the existence of a planet, scientists must follow it for one orbit. This hypothetical planet has an orbit that takes six million years to complete. No human astronomers live that long.
    • The detection method for these extrasolar planets involves watching the stars for wobbles. This method cannot work with our own Sun, because we are a part of the system that we would be observing. It's like trying to touch your elbows with your hand: you can touch your right elbow with your left hand, but you cannot touch your right elbow with your right hand. Sometimes, being too close can impede detection.
    • The only direct way we would detect this planet would be by its reflected light. At half a light-year, the sun would be merely a very bright star, 900,000,000 times dimmer than it appears from Earth. That's not much light to illuminate the world. Then consider that the reflected light must travel back the same distance, and you will see that not much light gets back at all.

  • So what you're saying is that Holst was right?
  • Could just be some large object, doesn't necessarily imply that it is a planet.

    What is the definition of a planet anyway, and what makes it different from an asteroid.

    Isn't this the 3rd tenth planet to be discovered in as many years?
  • but REALLY...how does this fall under "news for nerds"

    What do you mean, how is this "news for nerds"????

    Scientific news can't be classified as "news for nerds"? Loosen up your collar, man, let some more blood flow north. It doesn't just have to be computer- or technology-based news to be considered here for /.
  • Rupert? I hope you're right, because my first thought was that it was Unicron!

  • According to that article, the orbiting time is 6 million years.

    The last I heard, scientists gave our sun about another 5 billion years before it explodes.

    That means that the planet, if that is indeed what it is, will orbit the sun another 833 times, give or take a few, before the sun explodes.

    Are you, by any chance, off by a factor of 10^3? :)
  • According to that article, the orbiting time is 6 million years.

    The last I heard, scientists gave our sun about another 5 billion years before it explodes.

    That means that the planet, if that is indeed what it is, will orbit the sun another 833 times, give or take a few, before the sun explodes.

  • You're all wrong. Its obviously Mongo Planet of Doom.
  • Of course, you could also argue anything larger than size X is a planet (in which case the four Gallileians, Luna, Titan, and Triton are planets if Pluto is...), or any of a dozen other criteria.

    Yeah, but 'moon' is really a status, not a description. Titan would certainly have no disputers as to being a planet if its primary was the sun rather than Saturn. Triton probably *was* a planet -- the current theory runs that Pluto and Triton are the last survivors of a group of small icy/rocky planets outside Neptune's orbit, but that a single or multiple disasters led to Pluto being knocked into its elongated orbit, Charon possibly being formed from an impact with Pluto a la Luna, Triton being captured by Neptune, and possibly even Uranus' sideways tilt.

    The outer system looks like the remains of a driveby shooting... something big came by, but we don't know what or when!

  • I hacked a Java gravity simulator I wrote last year to show the hypothetical Planet 10 slingshotting comets into the inner solar system. The physics is quite realistic, but the scenario is very simplistic. I did just as a tool to show how knowing the trajectory of a number of comets can hint at the orbit of a perturbing body.

    The href is http://www.astro.wisc. edu/~dolan/java/planet10/Planet10.html [wisc.edu]

    Please send comments/complaints by email instead of posting.

    P.S. if you want a pretty accurate simulation of the solar system, crank the timstep down to a few days, zoom in and turn on the planets (options screen).
  • I think what you're thinking of is that one of Saturn's moons (Phoebe) orbits backwards (or retrograde) around Saturn. The thought is that this irregular-shaped, small moon is an asteroid captured by Saturn's gravity well. It is notable that Phoebe is Saturn's outermost moon (number 18 as of 1994).

    Jupiter also has four retrograde moons: Ananke, Carme, Pasiphae and Sinope, also the outermost moons of the planet (numbers 13-16 as of 1994)
  • If it wasn't in the ecliptic, it would not have much to interact with.

    Not true. The solar system is only flat (i.e. disk-like) out to about 100 AU or so - the outer edge of the Kuiper Belt. Beyond that, the Oort cloud is a spherical shell likely containing billions of proto-comets. Since these comet cores are arranged pretty much uniformly in 3 dimensions, the hypothetical planet would not need to be in the ecliptic to slingshot the comets towards the inner solar system.
  • I don't think it could be a brown dwarf. If it were, at 30,000 AU it would be visible to the naked eye (about 6th mag apparent), and significantly brighter than Neptune or Uranus.
  • There was no telescope involved. This hypothetical planet has not been seen.

    The comets in question have had their trajectories computed (there are difficult, but well-known procedures to calculate the 3D orbits of comets/asteroids/etc from their 2D positions in the sky - one was invented by Gauss). Once the trajectories are known (in the form of elliptical orbits around the Sun), you can figure out where in the sky the furthest point from the sun lies (called the aphelion). This is the point at which the comet was ejected from the Oort cloud at the fringes of our solar system.

    My understanding of this potential disocvery is that the 13 must all have aphelia which lie in a line in the outer solar system. This line would then indicate the trajectory of the perturbing body (our hypothetical planet in question) and yield a preliminary orbit.

    The high probability that this is not coincidence (1 in 1700) probably comes from the authors' calculations of whether the aphelia lie in the same region by chance or not. This calculation would take into account the uncertainty of the 3D location of the aphelia (since we couldn't have *seen* each comet at its aphelion - we can just extrapolate their orbits out to that point).
  • I think it spins on its axis a different way, but not orbits backwards
  • by Ivo ( 26920 )

    this must be the planet Rupert! (Ever read the 5th part of the Hitch Hiker's Guide to The Galaxy?)

  • Let's send a probe to that planet. Maybe they already have all this stuff there. :-)

    I'd really like to know what a Perfectly Normal Beast sandwich tastes like. :)

  • I seem to recall an article, oerhaps in Discovery News, about using a large magnetic field, and trapping ions in it. This setup functioned just like a solar sail, but doing away with the mass of the solar sail.
  • The IAU has no plans to do so. They considered it, but decided against it. They gave it the title "King of the Kuiper Belt" so it's feelings wouldn't be hurt.
  • I think that might have been one of Erik von Dainikken's books. he was famous for the "Chariots of the Gods" books; ancient astronauts, ufo's, Atlantis, etc. He filled 12 or 13 volumes with 'interesting' things. No I did not read them. I stopped halfway through COTG because the damn thing was near unreadable.
  • In my professional opinion as a janitor, I think that theory is a little weak on the evidence. Even if a huge mass was deflecting comets from the Oort cloud, why exactly would they consistently hit Earth every 20 million years? There's a lot of empty space out there- even if a whole legion of comets got sent our way, they would have much more chance of hitting us than shooting a bunch of electrons at a nucleus.
  • Umn, friend, you have an off-by-one error in your orders of magnitude:

    >If we attack it a different way, 30,000 times 8 light-minutes is 24,000 light-minutes, or 400 light-hours, or 16.7 light
    >days, which is only a bit over 1% of the way to Proxima Centauri, so this does not sound right either; it is hardly "a
    >significant fraction of the distance to the nearest star"

    Umno. 30,000 times 8 light-minutes is 240,000 light-minutes, 4000 light-hours, 167 light-days, a bit over 10% of the way to PC. A significant fraction.

  • This is not all new, because there has been a theory called the "nemesis theory" which is an extension to the catastrophe theory.

    And this theory has also been immortalized in a pop song! Shriekback [amazon.com]'s 1985 hit Nemesis, from the fabulous album Oil and Gold [amazon.com]: as far as I know, the only song about asteroid-based extinctions.

    priests and cannibals, prehistoric animals
    everybody happy as the dead come home
    big black nemesis, parthenogenesis
    no one move a muscle as the dead come home
    how bad it gets, you can't imagine
    the burning wax, the breath of reptiles
    god is not mocked, he knows our business
    karma could take us, at any moment
    cover him up, I think we're finished
    you know its never, been so exotic
    but I don't know, my dreams are vicious
    we could still end up, with the great big fishes.
  • I've heard that Pluto is in danger of losing its status as a planet, but what I've never understood is why Pluto was considered a planet but Charon was not. Charon is usually referred to as Pluto's moon, but my understanding is that Charon is actually about 2/3rds the mass of Pluto, so really they orbit around a common epicenter (that is not within either body, but between them.) So that sounds like a double planet to me, not a planet with a moon...
  • Hey Rob. What kind of transfer rates do you think Slashdot would get if we dropped the servers on this planet and strung it to earth with a couple bazillion miles of fiber? (Well. Other than the 208 day lagtime between and receipt, receipt, and then final delivery of the page. that is.......)

    Chas - The one, the only.
    THANK GOD!!!
  • Yep -- the Pluto/Charon barycenter is in the space between the two, and neither Pluto nor Charon ever move retrograde to their mutual orbit around the Sun.

    IIRC, the only other similar relationship between a "planet" and its "satellite" is Earth/Luna, where the barycenter is significantly outside the Earth's core and neither Earth nor Luna ever move retrograde to their mutual orbit around the Sun. (Every other satellite will, in its orbit around its primary, move the in the opposite direction of it's primary's movement around the Sun.)

    And, given that Luna is larger than Pluto, it's then easy to argue that the Solar System has eleven known planets: Mercury, Venus, the dual planets Earth and Luna, Mars, Jupiter, Saturn, Uranus, Neptune, and the dual planets Pluto and Charon.

    Of course, you could also argue anything larger than size X is a planet (in which case the four Gallileians, Luna, Titan, and Triton are planets if Pluto is...), or any of a dozen other criteria.
  • I remember hearing about "Planet X" in grade school.

    Seriously, though, it's a good bet that this is a brown dwarf (basically a small, dormant star).

    And yeah, orbiting the opposite way, it definitely doesn't sound like it was formed in the accretion disk around the Sun.

    Hey, but maybe we have something useful to send a probe to now past Pluto. Provided NASA doesn't botch it and mix up metres and yards.
  • The acceleration of a solar sail drops as inverse cube of your distance from the sun. It will very fast become comparable to friction from interstellar matter after you pass Pluto (cannot say off the top of my head but this can be calculated).

    It may be a feasible way to move things cheap and clean between earth orbit and mercury, venus and mars but that's about it.

    If you want to use solar sail your only feasible option for launching something fast past Jup will be to pull the crazy stunt of deccelerating towards the sun with the solar sail and using the sun's gravity well and the solar wind after that to get yourself up to max speed. In either case you are hardly going to get anything very high.

    A ion drive seems to be much more feasible (or a combination - start on sail, go towards the sun, use the well to accelerate, accelerate further on sail, dump it and continue on a ion).

    This of course assumes that someone will be able to get a working ion drive (in other words a decent proton accelerator in space). It does indeed have constant acceleration until you run out of reactive matter. And all you need is an electrical power supply. F.e. nuclear power generator and a tank of hydrogen to ionize and accelerate.

  • The nemesis theory describes a star, not a planet, so there is some difference.
  • a brown dwarf rather than a 10th planet. For years astronomers have been theorizing an as yet unseen large body in some kind of orbit around the Sun. It's more plausible that it's a Brown dwarf with enough mass to keep itself from being drawn into the solar system at large but not enough mass to keep from being caught in the Sun's deep space gravity well.
  • Ever cruise by the NASA site lately. Check up on the probes designed to sail on the solar winds. I'm sure the story was on here a coule of weeks/months ago. If deployed today, it would overtake Voyager in about 2 years.
  • Pluto is much larger than Ceres, the largest asteroid; 2274 km to 933 km. Even Pluto's moon is larger than Ceres (Charon is 1172 km), though Pluto is considerably smaller than Mercury (4,880 km) and both Pluto and Mercury are smaller than the moons Triton and Ganymede. But it's vastly bigger than any of the other trans-neptunian (Kuiper Belt) objects, or the Centaurs (TNO refugees between Jupiter and Neptune); Chiron is the largest Centaur and it's barely over 200km; the biggest known TNO is around 400km.

    Arguing that Pluto is merely the largest of a class of similiar objects doesn't seem to wash for me; you could say that the inner planets are merely the largest examples of a class of rocky objects inside Jupiter's orbit. The line between minor and major planet is essentially arbitrary, setting it in between Ceres and Pluto makes as much sense as setting it in between Mercury and Pluto. Since the former has been the standard for 70 years, seems no reason to change it. If a bunch of 2000km Kuiper Belt objects start turning up, they'll probably rethink.

    A more interesting question is whether Pluto should be considered a double planet -- the 2:1 ratio between it and Charon is by far the smallest in the solar system, and if I recall correctly the mutual point they both orbit around is actually *above* Pluto's surface, unlike any other satellite relationship known.
  • the effect is pretty conclusive. I have caculated that there is only about a one in 1,700
    chance that it is due to chance.

    That doesn't quite scan. I presume he means a one in 1700 chance that it was something other than a rogue planetary body.
  • Much to my dismay, Pluto has kept on as a planet, surving the most recent incarnation of controversy over it's real status. No astronomer worth his weight really thinks classifying Pluto a planet is anything more than convienient for confusable schoolchildren (i don't think that's a serious issue either i think kids could easily grasp and enjoy such a controversy).
    Simply stated: there are asteroids out there bigger than it. It's incredibly tiny. It has an unconventional, totally erratic orbit. It's made of ice, unlike any other planet out there, but very much like all the other crap floating around way out there, just inside (outside?) the solar system.
  • Check out the Nine Planets [seds.org] website... great for info about the solar system.

    Here's the Pluto page [seds.org].

    The main problems with Pluto's status as a planet are:

    • The mass is too small... only 1/6 as massive as Earth's moon. When originally discovered, Pluto was thought to be massive enough to exert a gravitational pull on Neptune, but now we know that's not the case. The discovery of Charon in 1978 helped pin down the combined mass of the Pluto-Charon system (basic astronomy... in a binary system, the orbital period is related to the sum of the masses).
    • It's not unique... it turns out that there are hundreds, maybe thousands of Kuiper belt [seds.org] objects out there at roughly the same distance as Pluto, many in 3:2 resonance with Neptune's orbit (just like Pluto). The first of these was 1992 QB1 (as the name suggests, discovered in 1992).

    So Pluto is just the biggest and brightest of a whole family of rock/ice "asteroids" out there beyond Neptune.

    Perhaps calling Pluto a planet is just an accident of history, based on a wild over-guesstimate of its true mass. But why rock the boat? And after all, Pluto is a couple of orders of magnitude more massive than the biggest Mars-Jupiter asteroids (Ceres, Pallas, Vesta, etc).

    PS, From the Nine Planets mass figures, Charon is 1/9 the mass of Pluto, not 2/3. But it's still pretty accurate to call Pluto-Charon a double planet.

    Earth-Moon is really a double planet too (despite 1/80 mass ratio), if you go by visual appearance... the difference in radius is much smaller than the difference in mass (volume is proportional to radius cubed, and the Moon is less dense than Earth as well).

  • Before reading the article I was saying to myself : "Hey this is cool, another planet in the Solar System!"

    After reading it, my mind had some doubt about the claims.

    How by studying only 13 comets, could someone arg that he as found a planet wich is several Jupiter masses at such a large distance.

    If he studied the path off known comets that already travel through the inner solar system, they certainly did nt travel far enough for their orbit to get significantly, in a observable way, altered bu such a distant object.

    For 13 comets to be affected by this distant object, they should all have similar orbits. If one comet as an elongated orbit wich is oposite of this object, it's orbit will not be affected in an observable way.

    In the light that Jupiter may have nuclear reaction in it's core (some theory exist about that possibility) an object with several Jupiter masses willl certainly have nuclear reaction in it's core and would emit some kind of radiation. At such a close distance from the Sun, it would certainly have been discovered long ago. We are able to observe brown dwarves at much longer distance.

    With a "six million" years orbit, no one can say that it is, in fact, orbiting the Sun (especially for an object that has not been observed).

    Finally, such a big object will certainly not be a planet, but some kind of star.

    In the shadow of all these doubt, I'll wait for the paper to be presented next week. Then I'll will listen to the comments of other scientist.
  • 208 days transmission time? That's not much longer than I usually wait for Slashdot to be served right here on Earth!
    1. Escape velocity is 25,000 MPH or so (from the surface of the earth; it is a function of altitude).
    2. The Space Shuttle is nowhere near our fastest booster.
    3. The Space Shuttle cannot get anywhere near escape velocity; it can get to an orbit at a few hundred miles altitude carrying no payload, and that's it.
    4. Omni is a poor guide to anything other than fiction. You are much better off using the Journal of the British Interplanetary Society, Analog, or even the sci.space FAQs.
    I just can't put it any nicer right now.
    Deja Moo: The feeling that
  • The ecliptic is a plane containing the sun and planets.
    The ecliptic is, IIRC, the plane of Earth's orbit. The other planets orbit in somewhat different planes. They're all pretty close, according to our best models, because the entire solar system was formed by condensation from an accretion disk around the proto-Sun. They didn't form in radically different planes and then get warped around to similar ones (there is no known mechanism for that), they were that way from their beginnings.

    If a planet was captured from outside the solar system, or if it was formed from a separate clot of gas and dust which was too far from the main accretion disk to be forced into the same orbital plane by gaseous drag, then it could easily have any orbital plane or direction. Posigrade, retrograde, polar... it is not constrained by anything we know of today.
    Deja Moo: The feeling that

  • Surely there must be some constraint if we assume that this object isn't extragalactic in origin?
    Nope. If you look at the sky, the Milky Way's plane goes from something like NNE to SSW; it's a long way from the plane of the ecliptic. A collapsing cloud of gas could have all kinds of swirls and eddies, especially if the collapse is driven by violent local phenomena like supernovae. Whatever plane the accretion disk winds up in will be the orbital plane of the planets it forms (or very close) but that doesn't have much to do with the orbital/rotational plane of the thing from which it formed. Look at Earth, which spins on an axis 23.5 degrees off from its orbital plane, or Uranus [enchantedlearning.com], which has an axial tilt of 97.9 degrees. You have all the disproof you could want right here in our own Solar system.

    If you have a second nucleus in the gas cloud which is gravitationally bound to the first one, but isn't in a region of gas density sufficient for friction to pull it into the same plane of rotation, anything that accretes from it will stay in whatever orbital plane it had to begin with (ignoring outside perturbations). And captured bodies can go any direction at all, depending on how they make their approach. There are no constraints of physics.
    Deja Moo: The feeling that

  • Unlikely. IIRC there is an inner-system planet with a moon orbiting in the retrograde direction (Neptune?), and the moon and planet (and the planet's other moons) have been going in opposite directions for as long as we can tell; neither influences the other much.

    Such a planet would have no influence on the plane of the inner planets' orbits, nor they upon it.
    Deja Moo: The feeling that

  • The acceleration of a solar sail drops as inverse cube of your distance from the sun.
    That's inverse square. Inverse cube is the fall-off rate for the static far-field from a dipole.

    Something like a StarWisp probe could investigate this in a short time. A StarWisp is essentially a very thin piece of metallic lace, and it is propelled by a microwave beam (a "light sail" that operates at microwave instead of optical wavelengths). It weighs a few grams; you hit it with a few gigawatts of microwaves and it takes off at an enormous acceleration. p = E/c, so 10 GW impinging on the sail with 100% reflection would yield about 67 N of force. If the probe weighs 10 grams, that is close to 700 G's of acceleration!

    If the cruising speed of StarWisp is 0.5 c, then it could do a flyby of this planet about a year from launch and we get the data 6 months later. That's quick enough to build the probe for your Master's degree and analyze the data for your PhD.
    Deja Moo: The feeling that

  • It is urgent that we dispatch a probe to Planet X as soon as possible.

    It is, after all, the sole remaining source of the Shaving Cream Atom, Illudium Phosdex.

    However, it will take quite a long time to get there. I wouldn't expect it before, oh, the 24 1/2th Century.
  • My point was not how is this news for NERDS...

    How is this NEWS?

    A many people have already pointed out, scientists have been talking about a possible Planet X for years...when I read the article...what news was there?

    Did they prove it exists? No...it's still just a theory they can't prove with existing technology

    Did they prove where it exists? No...two different groups are giving two different numbers...I don't know what the significant digits are but if you can't get anything more precise that "really really far away" what does that tell me?

    Even if I was the most die hard astronomy fan, I don't see anything in this article that leads me to believe anything newsworthy has happened here. For the record...I think there is a Planet Y in orbit at least 50000 AU away. Do have any conclusive proof, but it's still a theory and maybe someday, there will be a away to prove it and they'll have to call it planet JoeShmoe.

    - JoeShmoe

    -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= -=-=-=-=-=-=-=-
  • A few years back I read a book written by some sort of ph.d (one of those researchers who has a degree but whose ideas are so far fetched that no one else in his field believes him... every field has one..) that wrote of a planet that orbits our sun, but from very,very far away... the name of the book was "The Thirteenth Planet". It basically described humans being visited by powerful creatures that lived on this 13th planet and cited biblical and other ancient religious tomes pointing to the various instances where "holy" or "sacred" events occurred and tried to prove how these could only be done by these "aliens".. anyway, i digress, i'm not saying this guy is right or even sane, but the 13th planet was so far away that it only came near (relatively) to earth every like 2000 years.... like i said, i'm not one for human origins being tied to aliens (i'm a big evolution buff) but it makes me wonder how closely (if even) this is tied into that guys works or if the "ancients" ever knew about this planet....

    great, now i'm going to officially be named a psychopath on /.

  • By analysing the orbits of 13 of these comets, Dr Murray has detected the tell-tale signs of a single massive object that deflected all of them into their current orbits. "Although I have only analysed 13 comets in detail," he told BBC News Online, "the effect is pretty conclusive. I have calculated that there is only about a one in 1,700 chance that it is due to chance."

    Observing at that distance, what is the resolution of the tools (telescope?) he is using? And of the many calculations to determine trajectory for 13 different comets, what would be the probability for error?

    Also, at that distance, the view we would get would appear to be effectively two dimensional with small depths very hard to perceive. Yes/no??
    That being the case, how would the they determine the trajectory for a comet that would be three dimensional, without all the info?

    But the new planet would be 30,000 times more distant from the Sun than the Earth, putting it a significant fraction of the distance to the nearest star.

    What does he mean by significant fraction?
    1/*000 ?
    1/*000000 ?
    1/*000000000 etc.....

    Being so far from the Sun - three billion billion miles - it would take almost six million years to orbit it.

    That being the case, how can they be sure it is orbiting our Sun?

    Hope someone can shed a little light on these for me...


  • Lets just bring it here...
  • by Yarn ( 75 ) on Thursday October 07, 1999 @01:09AM (#1632524) Homepage
    dude, the planets going the opposite direction to us... imagine how tangled the cable's gonna get, and dont mention the boosters... argh.
  • by XNormal ( 8617 ) on Wednesday October 06, 1999 @11:10PM (#1632525) Homepage
    As I see it he means that the orbits of the comets he studied, their vectors and timing have only a 1:1700 of having the relationship they have by chance, without a single large body deflecting them (assuming his math is correct, that is)
  • by XNormal ( 8617 ) on Wednesday October 06, 1999 @11:14PM (#1632526) Homepage
    The so-called Nemesis [geocities.com] theory is about 14 years old - a large planet with extremely long period deflects comets from the Oort cloud and is responsible for mass extinctions like the dinosaurs which appear to be happening periodically.

    The new thing here is that someone has actually calculated a probable orbit.

  • by Mr. Flibble ( 12943 ) on Wednesday October 06, 1999 @10:57PM (#1632527) Homepage
    From what I can gather he was unable to detect it directly. He has inferred the location and approximate mass through studying the alteration of the comets paths. Hence it is speculated to be there. My guess as to how he assumes that it is orbiting the planet is again by mathematical calculations. I assume that the 13 comets studied had known paths as they left the solar system, and altered paths as they returned (well, I guess they did not REALLY leave, but you get the idea)

    By calculating how much they were altered and the angle that they were altered by, it is possible to determine the location and mass (to some degree) of the altering influence.

    Its like shining a light on an object, you dont ACTUALLY see the object itself (although we believe that we do) you see the light that has been reflected by the object. We cannot see the suspect planet, but we can detect its gravitational influence on the comets themselves.

    This all taken in context that his observations and math are correct...
  • by Xuff ( 99173 ) <[xuff] [at] [xanthra.com]> on Wednesday October 06, 1999 @10:44PM (#1632528) Homepage
    What do you mean what does it mean? It means this massive object orbiting our sun could be the mothership of those blasted aliens that live in our washer/dryers and steal our socks, underwear, and other items of clothing to power their cold fusion engines and provide their replicators with raw material. Think about it, they're probably using their tractor beams to deflect the comets from hitting us so their greatest supplier of raw materials doesn't die out!
  • by Chocky2 ( 99588 ) <c@llum.org> on Thursday October 07, 1999 @02:31AM (#1632529)
    Astrophysics stuff...

    Kepler's laws say that the square of the period is approximately proportional to the cube of the radius (and using the right units, years and AU) equal. Which makes the orbital period just over 5 million years.

    The sun won't expand until it runs out of hydrogen and starts helium burning, even then it probably won't expand beyond the radius of Mars. Pluto will get a bit cooked, but it won't be swallowed up, the Jupiter and maybe Saturn could start to evaporate which would be really cool to watch if we weren't dead. And as the others said this ain't gonna happen for another five or six billion years, and it won't go BANG! though there will be a little pop! as it blows off it's outer layers to make a planetary nebula which will look really pretty if you're a couple of hundred light years away and not dead. Callum (just another astrophysics geek)

  • by Falsch Freiheit ( 7780 ) <[freiheit] [at] [gmail.com]> on Wednesday October 06, 1999 @10:57PM (#1632530) Homepage
    Hey, but maybe we have something useful to send a probe to now past Pluto.

    With a distance of almost half a light year, we'd either have to be very patient or come up with a method to send a probe much faster. (And, then, after we've figured that out, we can be about a dozen times as patient and send a probe to the nearest star.)

    At the very least, it's far enough away that the fastest way to get there is to spend quite some time coming up with a faster way to send things there. (Orbital rail-gun, anybody?) I mean, seriously -- get something started at about 1800 miles per second (fast enough to get to the sun in 13 hours) and it'd still take you almost 50 years. Take 10 years to come up with something twice as fast and you'd get your probe there 15 years earlier.

    In other words, it's a bit distant to be trying to send probes there just yet.

This process can check if this value is zero, and if it is, it does something child-like. -- Forbes Burkowski, CS 454, University of Washington