Slashdot Mirror
A 10th Planet in Our Solar System?
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?
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.
--
And this theory has also been immortalized in a pop song! Shriekback 's 1985 hit Nemesis, from the fabulous album Oil and Gold: as far as I know, the only song about asteroid-based extinctions.
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!!!
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.
Baker's Law: Misery no longer loves company. Nowadays it insists on it
http://www.sigsegv.cx/
The nemesis theory describes a star, not a planet, so there is some difference.
-matt
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.
I'm a loner Dottie, a Rebel.
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.
Dan. -- So what if it's spelt wrong, nobody's perfect
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 website... great for info about the solar system.
Here's the Pluto page.
The main problems with Pluto's status as a planet are:
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.
- Escape velocity is 25,000 MPH or so (from the surface of the earth; it is a function of altitude).
- The Space Shuttle is nowhere near our fastest booster.
- 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.
- 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
Time is Nature's way of keeping everything from happening at once... the bitch.
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
Time is Nature's way of keeping everything from happening at once... the bitch.
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
Time is Nature's way of keeping everything from happening at once... the bitch.
Such a planet would have no influence on the plane of the inner planets' orbits, nor they upon it.
--
Deja Moo: The feeling that
Time is Nature's way of keeping everything from happening at once... the bitch.
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
Time is Nature's way of keeping everything from happening at once... the bitch.
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
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
-- I wonder which will go down in history as the bigger failure: the War on Drugs or the War on Filesharing
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
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?
What does he mean by significant fraction?
1/*000 ?
1/*000000 ?
1/*000000000 etc.....
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...
cheers
marty
"I can't buy want I want because it's free. Can't be what they want because I'm me." -Corduroy, Pearl Jam
Lets just bring it here...
People who bite the hand that feeds them usually lick the boot that kicks them
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)
Stop worrying about the risks of nuclear power and start worrying about the risks of not using nuclear power.
The so-called Nemesis 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.
Stop worrying about the risks of nuclear power and start worrying about the risks of not using nuclear power.
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!
-Xuff
Homepage & W
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)
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.