Slashdot Mirror
Two Planets Found Sharing One Orbit
dweezil-n0xad writes "Buried in the flood of data from the Kepler telescope is a planetary system unlike any seen before. Two of its apparent planets share the same orbit around their star. If the discovery is confirmed, it would bolster a theory that Earth once shared its orbit with a Mars-sized body that later crashed into it, resulting in the moon's formation."
Quick, we need to redefine the meaning of "planet" yet again.
Win a signed Stephen Carpenter ESP Guitar from the Deftones: http://def-tag.com/?r=0008781
That there's a duplicate Earth on the exact opposite side of the Sun!
First rule in government spending: why build one when you can have two at twice the price?
This is more liberal lies. Bill O'Reilly told me that you can't explain that!
What a fool believes, he sees, no wise man has the power to reason away.
I always assumed that Dantooine and Tatooine were twin planets like this. Or did that mean something else?
I swear to God...I swear to God! That is NOT how you treat your human!
That there's a duplicate Earth on the exact opposite side of the Sun!
OK, just for the fun of it: what would be the most efficient method to check this hypothesis?
By checking how its gravity would effect other planets in the same star system. For background: Counter-Earth on Wikipedia, Lagrangian point L3 on Wikipedia, and Counter-Earth on TV Tropes. Executive summary: We don't have one, and we know this because if we did, we'd be able to detect its pull. Furthermore, such an orbit would be unstable.
It's not clear that this is anything new. A number of astronomers have suggested that we should treat the Earth/Luna and Pluto/Charon pairs as "double planets" sharing an orbit. And there's a pair of Saturn's moons that share an orbit. Of course, whether these are counterexamples depends on the picky, legalistic details of how you define the term "planet", which we've discussed to death here on /. already. Fun as such pseudo-arguments may be, the fact is that they're not terribly significant.
Thus, for the Pluto/Charon pair, reclassifying Pluto as a "dwarf planet" make it especially an edge case, since it still includes the term "planet" in its classification. But they're both large, spherical bodies in a single orbit around the sun, while also orbiting each other.
The Earth/Luna pair is a bit of a mathematical curiosity. One of the arguments supporting calling our moon a "planet" orbiting the sun is that its orbit is everywhere convex with respect to the sun. You'd expect a "moon" to have a much more wiggly orbit, parts of which are curved away from the sun, and this is true of the other objects in the solar system that we call moons. OTOH, the barycenter of the Earth/Luna pair is (slightly) inside the Earth, which can be used with some definitions to say that it's really a satellite of the Earth.
And, of course, Saturn's two moons in a single orbit can be disqualified because they're obviously not "planets". They're not even big enough to be spheroidal, which is required by most definitions of a planet.
But the fact remains that our solar system contains at least three example of paired bodies sharing an orbit about their primary, and periodically exchanging the lead position. The mechanics of such orbits have been long understood, and astrophysicists can tell you when such orbits are stable. So while this may be "news" in the sense that it's about such orbits around another star, it's hardly news in the astrophysics sense.
What'll be interesting news is the discovery of three astronomical bodies in a "Scottish reel" orbit, which was proved possible several years ago, but to my knowledge hasn't actually been observed yet. Possible places to find them are in the asteroid belt, in Jupiter's "Trojan" asteroid clumps, and in the Kuiper Belt.
Those who do study history are doomed to stand helplessly by while everyone else repeats it.
how is this amazing. there are an infinite amount of things in the skies... I wouldn't be surprised to see a new Galaxy that had an outline shaped like a Penis
I think they've already found one in the Porn Cluster ... I think it's called the Sheen Galaxy.
Yes. Please say nothing more of Gor, thank you.
The problem with the planet detection methods used by the Kepler team is that it is all calculated based on occultations; the slight dimming of the star's light as a planet passes between that star and the Kepler satellite. This only works if the planet in question is 1) HUGE or 2) very close to the star or 3) the Earth just HAPPENS to be in the plane of the planet's orbit around the star. That's why we're discovering so many enormous planets with orbital periods in the range of only a few days. But the nice thing about the Kepler data seems to be that it's eliminating many of the "it could NEVER have happened that way!" explanations. With upwards of 500 billion stars in the Milky Way galaxy and we've looked only at a few thousand, it looks more and more that ANYTHING is possible when it comes to planetary formation.
Oh, sorry, typed it wrong...
What two consenting planets do doesn't affect other planets' orbits.
Slashdot "libertarians": Small government for me, big government for those I disagree with. -1, I disagree with you
Captain Kirk beams down there, takes his shirt off, and gets the chick. Wait, two planets? Wait a second, we'll have to fly in a second, evil, Captain Kirk from a parallel universe. And how about a Spock with a beard? Does Ryanair fly there? Can we get a discount rate for two? Well, knowing them, they'll charge an extra exorbitant fee for Spock's beard. And the plane won't even land in the parallel universe, but in another universe, "Really close by!"
Schroedinger's Brexit: The UK is both in and out of the EU at the same time!
There is a ridiculously enormous amount of data. Numerous cameras, totaling to almost 100Mpixels 'blinking' every 6 seconds. Assuming a minimum of 4 bits per pixel, that would be at least 720 Gb every 24h, that somehow have to be transmitted to a station on Earth from wherever the hell Kepler is. And nor that traffic includes flight and error control, neither the maintenance and diagnostics on the on-board computer is included in the former calculation. Plus, for some reason, there is not enough bandwidth to accommodate all available throughput.
As for post-retrieval data processing, what does it tell you that mission officials are seeking civilian help in interpreting data?
The three laws of thermodynamics:(1) You can't win. (2) You can't break even. (3) You can't even quit.
Our orbit isn't perfect. So maybe the counter earth would be visible in the sky just beside the sun. But would go behind it and reappear out the other side each time one of the planets passed perihelion. Is our orbit eccentric enough for this?
Kepler has identified 1200 planet candidates in its first four months of data operations, 19 which had been confirmed as of last week. Graphing the planets by various attributes starts to give a respectable idea of size, year, star-type, density and perhaps other attributes in solar systems. Kepler could find ten times as many planets as these in its 3.5 year nominal, 10-year extended, mission.
These planets are at the stable lagrange points, not in orbit with each other.
Which, by the way, is perfectly fine with regards to the IAU's definition. These planets have cleared their orbit nicely, and are gravitationally bound to each other.
Prediction for end of Universe #42: Fencepost error in Quantum_bogosort.cpp
...is filing a few billion John Doe lawsuits against "Any and all current or potential occupants of said potentially planetary bodies..." for sharing an orbit.
Sharing is bad
How come Slashdot never gets Slashdotted?
Both are to be considered "dwarf planets"
We prefer the term "little planets"... (you insensitive clod!)
Because the universe has a finite age and light has a speed limit, there are a finite (though still very large) number of things we can see in the universe. Further, as far as we can tell everything in the universe obeys the same laws of physics. Thus we don't necessarily expect infinite variation in the cosmos - there should instead be a good deal of uniformity. When something unusual or exceptional occurs, it's interesting because it wasn't necessarily expected that such a thing could exist.
There were 12 planets all sharing orbits, orbiting in some stars habitable zone.
But then again there were angels with awesome tits running around too.
Two planets orbiting the same star is arguably only possible with horseshoe orbits. If two objects are of similar size so on cannot say one orbits the other, it is described a a double body rather than primary and satellite.
A Lagrangian moon will likely develop into a horseshoe orbit over time.
don't cut it off www.mgmbill.org
Planet...or space station?
DUNH DUNH DUNH!
Having at least one X chromosome makes you female enough for hating John Norman's works. Actually, I don't care about the content but that man's infernal writing style is bad enough that the Goreans (in-book, not the BDSM subculture) could use it to break their slaves' minds... Well, if they needed anything more than a few stern words to do that.
USE HOT GRITS WITH STATUE OF NATALIE PORTMAN (NAKED AND PETRIFIED)
1. read slashdot ...
2. attempt humor
3.
4. PROFIT!!!
Two planets cohabiting an orbit; what could be funny or profitable about that?
Yes, the Earth and the Moon share the same orbit too.
Please mod me 1 or troll. It's where the truth is these days, even on Slashdot. Beware the power of moderators everywh
In theory, matter in a disc of material around a newborn star could coalesce into so-called "co-orbiting" planets, but no one had spotted evidence of this before.
Off course not. Even star turtles like a little privacy.
Nae king! Nae laird! Nae yurrupiean pressedent! We willna be fooled again!
The derivation of Lagrange's result linked from the NASA page you just linked is probably about as good as any explanation you'll find outside a $100+ textbook, and better than some of those as well.
"I can't imagine how things could get any worse!" (some guy) "That could just be failure of imaginatioÂn on your p
Finally, somebody has discovered a counter Earth!
Okay, they had to look in another solar system so it's not really a counter "Earth," but still. The real question is whether this will inspire John Norman to publish a new installment in his Gor series.
Nine for Mortal Men doomed to die...
Doppelgänger (Journey To The Far Side Of The Sun).
Isn't an orbit determined by the center of the rotation? The Earth is in orbit around the Sun and the moon is in orbit around the Earth.
Why isn't moon capitalized? Because it's not a planet! Now go to your room!
The Moon is capitalized because its a proper noun in this usage. In general usage we call the moon that is orbiting the Earth simply "the Moon". And since there is only one moon orbiting the Earth and it is referred to as the Moon, it is correct to capitalize it.
In the solar system there are many moons but there is only one Moon.
No, not belts. You know. Like, rings, dude. You know that's what Kepler's *really* for, right?
These are my friends, See how they glisten. See this one shine, how he smiles in the light.
No, but I've had sex with plenty of them. Does that count?
No, but I've had sex with plenty of them. Does that count?
[CITATION NEEDED] /. after all.)
(This is
How is the Riemann zeta function like Trump rallies? Both have an endless number of trivial zeros.