Backyard astronomers and astrologers alike are bound to welcome the announcement of three new planets in our solar system!
By next month our Solar System is expected to officially contain twelve planets, meaning astronomy texts and astrological charts will have to be republished. The new lineup in order from the sun will now be Mercury, Venus, Earth, Mars, Ceres, Jupiter, Saturn, Uranus, Neptune, Pluto/Charon and 2003 UB313 (nicknamed Xena).…
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— go to most recent comments76 - Jet in Columbus
REUVEN!!!!-If I didn't know your situation, I'd say you deserved to be shot for that joke. Now go to your room without your cornflakes and stand in the corner.
oy vay
77 - Richard Brodie
I think it is legitimate to ask what the purpose and potential benefit is of redefining the term "planet" to mean something other than "Those major celestial bodies that rotate in their own widely separated orbits around the sun, with or without other smaller satellite bodies called mooons." - a definition which includes the traditional nine, plus Xena and whatever others might remain to be discovered.
Ceres remains an "asteroid", i.e "One of a group of celestial bodies of varying sizes that rotate around the sun in more or less the same orbital swath." Again what is accomplished by calling Ceres a planet, just because it is larger and rounder in shape that all of its other sister asteroids?
Charon remains a "moon" by virtue of being the smaller of two bodies which rotate around each other. Again what is gained by calling Charon a planet, based its center of rotation being above the surface Pluto, while NOT calling Luna a planet merely because its center of rotation is below the surface of Terra?
Ockham's Razor is the principle proposed by William of Ockham in the fourteenth century: "Pluralitas non est ponenda sine neccesitate", which translates as "entities should not be multiplied unnecessarily." Allow me to propose Brodie's Razor: "Concepts should not be changed and/or complicated unnecessarily."
78 - gonzo marx
wow...then i guess we had best go back to the Aristotlean definition of what an "atom" is, that way we don't expand on definitions as we learn more...
does this mean we have to define the Earth as flat too? since it was the "definition" and "Brodie's Razor" doesn't want more complex explanations that are more accurate to replace whatever was "traditional" before new information or discoveries made the old definition incomplete or obsolete
here, i had never thought everything coudl be so .....simple
/end snark
Excelsior?
79 - Richard Brodie
gonzo suggests that the new definition of "planet" is somehow "more accurate": explanations that are more accurate
So, since you either don't want to or can't answer my question as to what exactly is the reason, purpose, use, value, and benefit to this redefiniton of the term "planet", perhaps you could at least explain in what way you see it as being "more accurate."
80 - duane
Actually, Richard (#77) makes a defensible point by questioning the purpose of the proposed nomenclature revamp. This is certainly part of the debate going on with the 90 or so astronomers arguing at the IAU Assembly. I'm pretty sure that the proposal has nothing to do with the "whole liberal PC, European Civilization destroying agenda," however.
The majority of astronomers at the meeting are against the proposal in its current form.
The "hot topic" is what to do about Pluto. Many astronomers think that Pluto should never have been named a planet in the first place, and that we should go to an 8-planet roster.
81 - gonzo marx
i can easily agree that this should be debated and looked at... all part of scientific process
my whole snark was the idea that definitions shouldn't change within the scientific community
Richard, i DID answer you.. definitions need to be updated as new data makes information more accurate, or changes previous conceptions
is this one of those instances?
perhaps, that's what is being discussed and debated by those who know far more about it than this gonzo
sooOOoooOOOooOOOooo... "where's the beef?"
Excelsior?
82 - Jet in Columbus
Richard 77: you can spout platitudes and dispute till doomsday, but the fact that you can not change nor can you argue with is that the official scientific body as redefined the definitions.
Whether you like it or not,
Whether you dispute it or not,
That is a fact you can not change!
Live with it and move on.
83 - Jet in Columbus
Gonzo, Gonzo, Gonzo, Gonzo, Gonzo, do you really think he's listening to you?
84 - Jet in Columbus
Richard-The International Astronomical Union, no matter how stupid you think they are, has the last say in the matter.
If they say the sky is blue and you happen to be under a thunderstorm and say it's gray, guess what they win.
come out of the rain
your umbrella has a hole in it.
Tantum meus sententia
Jet
85 - Jet in Columbus
Duane 80, as I pointed out in my article, Pluto was made a planet because when it was discovered they thought it was the same size at earth.
Pluto will stay a planet for only one good undesputable reason.
We've all considered it a planet for so long. That's sort of along the same lines of why we all still use a QWERTY keyboard even though a better and more efficient arrangement has been suggested.
"Mankind is more disposed to suffer with evils that are sufferable, than to right themselves by abolishing the forms to which they are accustomed"
because of this if Pluto has to be accepted as a Planet, than Xena does too. I agree that Ceres doesn't deserve the title, but I have no more business or credentials to argue with the IAU than do any of us...
Tantum meus sententia
Jet
86 - Jet in Columbus
Gonzo 81-Indeed!
87 - Richard Brodie
I really didn't expect any of you Pavlovian slavs to be able to give me an answer. You're all totally conditioned to accept, without questioning, anything that comes down as politically correct doctrine from the ivory towers of an apallingly self-censored and one-sided academia. This predictable lock-step reponse of the brainwashed faithful is usually seen in the humanities. In this case we see it spilling over even into the sciences, where again we see a very predictable enthusiasm for anything that proposes to turn long established tradition upside down. What a pathetic bunch of lemmings you all are.
88 - gonzo marx
Richard... did you miss #81 where i specifically address yer Question....again?
seems so
is it just your knee jerk reaction against anything outside of your pre-Conceived notions that you object to? or somethign more specific?
what do you propose to do when new information renders old terms and definitions inaccurate?
besides bitch, that is...
Excelsior?
89 - Jet in Columbus
Richard-are you using a QUERTY keyboard to type your messages when a better system is readily available or are you being a lemming like the rest of us?
see comment 85
Tantum meus sententia
Jet
90 - duane
Jet, it hasn't been decided yet. It's a PROPOSAL. Read #80.
Why are you trying to stifle Brodie?
... but I have no more business or credentials to argue with the IAU than do any of us...
I will obey. Ummm ... no further comment.
Gonzo, as you know, definitions and classifications change periodically as new knowledge comes to light. Usually, the classifications reflect an underlying fundamental commonality bestowed by Nature. Sometimes classifications reflect a simple commonality in observed phenomena, where the underlyng cause is yet to be recognized. These latter classifications are more an aid to communciations between specialists than anything else, kind of a shorthand way of speaking or writing -- for example, an "intermediate polar" (or IP) is a type of binary system in which one member is a white dwarf with a high magnetic field that accretes matter from a low-mass main sequence star in close orbit. It's a lot easier to say "IP."
So one has to ask what is fundamentally different about various pieces of rock such as Ceres and Pluto. Or one has to ask if the new nomenclature makes communications easier.
91 - Jet in Columbus
Gonzo, you're just no fun when you're making sense...
92 - duane
Lemming? Moi? Hehe. Calm down, Brodie. I was actually sticking up for you. You have a point to make? Try to make it without the insults. Some people have such short fuses around here. Sheesh.
93 - Richard Brodie
Richard, i DID answer you.. definitions need to be updated as new data makes information more accurate
I would not dispute this, but that's not what I was asking. I was asking HOW is this redefinition - not even based on any new data, btw - more accurate.
You were honest enough to say that you don't know. And I apologize for lashing out, but I get tired of being continually attacked, personally, for having non-PC positions.
94 - gonzo marx
to both duane and Riochard... no worries
it IS all about discussion and communications
and both of you raise extremely valid Points, which is why the eggheads are having this discussion and trying to hammer all this out
i'm not in either "camp" on this one, just a bit excited that those eggheads are actually looking at all this and trying to more accurately define/describe our Universe based on new information and interpertations
silly of me, i know... but i get all hot and bothered over the forward progress in these fields, for some reason i find it kinda Important
Excelsior?
95 - Jet in Columbus
Duane, were I a member of the IAU, I could see a justification for debating definitions, but I'm not, as are none of us.
Therefore I go along with people who know more about it than I do-after all it's their decision not ours.
I'm using a querty keyboard because that's what I'm used to. Someone else came along and invented a better system that's more efficient, but that doesn't mean I have to use it. It's the same as Mr. Brodie-someone has ocme along with a better system, but he doesn't have to use it.
However...
As more and more people use then next system, we'll become more and more obsolete, so I'd say it's better to learn the new system and stay current.
Ten years down the road kids will have been taught that there are 12 planets and if we say there are only 9 well be looked at like doddering old fools...
there are thousands and thousands of articles being published that the IAU's decision has already been made from the Pittsburgh Press to CNN.
Who am I to argue?
Who are WE to argue?
Tantum meus sententia
Jet
96 - gonzo marx
well Jet, taking the devil's advocate position here...
ANYONE can Argue on these matters...
it is precisely BECAUSE people can and do Argue that a lot of progress gets made
mebbe it's just me, but i place NO faith in authoritarian pronouncements until and unless they show their Proof and lay out the Work that lead to the conclusions under discussion
THEN comes the Argument part... everybody's invited... try and tear it down
if and when it survives all that, THEN we have a working hypothesis
the scientific method and all that, predicated on exactly what we are doing here, arguing and trying to shoot holes in each other's theorems
a messy process, i know, but i ain't seen or heard of a better one yet...(despite ID proponents, of course)
Excelsior?
97 - duane
Jet, just a note for future reference, because I've seen this happen several times before at BC. You should never assume anything about the qualifications or credentials of posters or commenters at BC. Just to give you an example; as it happens, I am a member of the IAU, among other professional societies. The IAU is not a monolithic bureaucratic entity. It's made up of astronomers and other types of scientists from around the world, and believe it or not, they are mostly not your authoritarian types. And Brodie, they certainly aren't PC. They hate that shit. I'm not a planetary astronomer, so I'm following this stuff just like you guys are, and I'm interested to hear what they come up with. As far as the reasons for the proposed changes, I have some cynical guesses, but I'm going to wait on that before I open my big mouth.
98 - Jet in Columbus
To all-especially Duane and Richard-unfortunately I've posted too many articles at once and I'm getting a little frazzled and frayed at the edges.
I have a particularly annoying smartass on another string who seems to live to annoy me and won't comment on the subject at hand-determined to just sling childish insults instead.
I'm a little short fused and I've been taking out on you and I do sincerely apologize.
I was wrong to do so.
Jet
99 - duane
Damn right Gonzo (#96). Good call.
100 - Deano
I just want to get these muther-f@#$ing planetoids off my muther-f@#$ing plane...t list.
101 - Jet in Columbus
since we all seem to be typing at the same time I refer you back to comment 98
102 - gonzo marx
thanks duane, and i can guess at your "cynical" speculations...
all the more Reason for this discussion on every level
oh yes, yer a member of the IAU?
/swoons
will you have my cyber-babies?
Excelsior?
103 - Jet in Columbus
'nuf said Duane
104 - duane
Gonzo, any dipstick with a few publications can be a member. I really didn't want to mention it except that I don't like hearing that kind of "who are we to argue?" kind of talk.
105 - Jet in Columbus
Duane, why arent you in Prague and did you read 98?
106 - Jet in Columbus
Okay a serious question. Is there a monolithic planet/dead star/dreadnaught out in the Oort cloud steering comets and if so why aren't they orbiting it instead of our sun?
107 - duane
No problem, Jet. Stay frosty.
As far as the Prague meeting, I have to pick and choose from among dozens of meetings to go to every year. The last IAU meeting I attended was in Sydney, and frankly, it just isn't my cup of tea. It's too big, too general. It is all-encompassing. Because of that, it's broad but lacks the depth that I prefer at a meeting. I prefer to attend specialized meetings where my subjects are the highlight. Not to mention that overseas travel is wearying to my aging bones.
108 - gonzo marx
first guess would be that the gravitational field or the shape of the comet's orbits are influenced by said body, but not enough to be tidal locked into an actual orbit around the body in question...
on the other hand, it could all be part of my master Plan as your new Galactic Overlord
now, i'll just have to take Darth Cheney in as my new "apprentice"
but i digress
Excelsior?
109 - Jet in Columbus
From USA Today-yesterday
A 12-person committee representing the world's largest group of planetary scientists on Thursday threw its support behind a new planet-defintion proposal that would increase the tally of planets in our solar system to 12.
More dissent emerged, too, from several prominent planet experts.
The definition, proposed yesterday at a meeting of the International Astronomical Union (IAU) in Prague, preserves Pluto's planet status and essentially classifies as planets all round objects that orbit the Sun and do not orbit another planet. The tally of planets is expected to eventually soar into the hundreds if the resolution is passed by a vote next week.
The Division for Planetary Sciences (DPS), a group within the American Astronomical Society, has the opposite view. The 12-member DPS Committee, elected by the membership, "strongly supports the IAU resolution," according to a statement released Thursday.
"The new definition is clear and compact, it is firmly based on the physical properties of celestial objects themselves, and it is applicable to planets found around other stars. It opens the possibility for many new Pluto-like planets to be discovered in our solar system," the DPS statement reads.
An informal SPACE.com survey of astronomers who study planets in and out of our solar system found six in favor of the resolution and seven against. A separate private straw poll being conducted by the National Academies of Sciences has so far yielded an overwhelming "No" response, a source told SPACE.com.
'Terrible definition'
Clearly no consensus has emerged, however.
"I think it's a terrible definition," said David Charbonneau, a researcher at the Harvard-Smithsonian Center for Astrophysics who searches for and studies planets around other stars. Charbonneau joins two other astronomers close to the issue who sharply criticized the plan].
Charbonneau said the definition was motivated by a desire to determine whether Pluto and another object, 2003 UB313, are planets. But the IAU now says there are a dozen other objects that might be planets but need further study.
"It is ironic that we are left with more, not fewer objects for which we are uncertain of their 'planetary' status," Charbonneau told SPACE.com. "Perhaps astronomy will undergo a schism, with sects of astronomers proclaiming different numbers of planets."
"As representatives of an international community of planetary scientists, we urge that the resolution be approved," said the DPS statement, signed by chairman Richard French of Wellesley College.
In an e-mail interview, French said he supports the defintion but realizes its shortcomings.
"My own personal definition would have been different from the final IAU resolution, but scientists have been stalemated for years by defending their own pet definitions," French said. "I understand the appeal of a simple declaration that Pluto is no longer a planet and that the solar system has only eight, but I also think there is value in the present definition that has applicability to planets around other stars as well."
The DPS has about 1,300 members, at least one-quarter of which are outside the United States. The statement does not represent the views of all members, said DPS Press Officer Sanjay Limaye. "There has been some feedback saying, 'I don't like it,'" he said.
'Worst' decision
The definition would make a planet of the asteroid Ceres and also reclassify Pluto's moon Charon as a planet, on the logic that the center of gravity around which Charon and Pluto orbit is not inside Pluto but rather in the space between them. (Earth's moon orbits our planet around a center of gravity that is inside Earth.)
Pluto and Charon would be called a double planet, and they'd also be termed "plutons" to distinguish them from the eight "classical" planets. Ceres would be termed a dwarf planet.
The definition entirely misses the key element of a solar system object, namely its role in the formation of the solar system," Charbonneau said. "There are eight fully formed planets. The other objects " Ceres, Pluto, Charon, [2003 UB313], and hundreds of thousands of others, are the fascinating byproducts of the formation of these eight planets."
David Jewitt, an astronomer at the University of Hawaii who searches for objects in the outer solar system, told SPACE.com that the proposal is "the worst kind of compromised committee report."
Jewitt has long avoided the whole debate over whether Pluto is a planet "because I think it is essentially bogus and scientifically it is a non-issue." He waded in reluctantly this week.
"Scientifically, whether Pluto is also a planet is a non-issue," Jewitt writes on his website. "No scientific definition of planet-hood exists or is needed. Is that a boat or a ship? It doesn't matter if you are using it to float across the ocean. Scientists are interested in learning about the origin of the solar system, and setting up arbitrary definitions of planet-hood is of no help here."
Geoff Marcy, who has led the discovery of more planets around other stars than anyone, called the definition arbitrary.
"Pluto, its moon, and large asteroids cannot suddenly be deemed planets," Marcy said in an email interview. "How would we explain to students that one large asteroid is a planet but the next biggest one isn't?"
Astronomers made a mistake when they deemed Pluto a planet in the 1930's, Marcy and many other astronmoers say. "Scientists should show that they can admit mistakes and rectify them," he said.
'Just might work'
However, one mild endorsement came today from Brian Marsden, who heads the Minor Planet Center where asteroids, comets and other newfound solar system objects are catalogued.
Marsden was on an IAU committee of planetary scientists that tried for a year but failed to come up with a definition for the word "planet," which was never needed until recent discoveries of Pluto-sized worlds out beyond Neptune. The newly proposed defintion was crafted by a second IAU committee of seven astronomers and historians.
Marsden is a firm believer that there are eight planets, but the new proposal has him sounding more flexible than in the past.
In an e-mail message from Prague, Marsden said the new definition is "intended to satisfy the eight-planet traditionalists (such as myself) and the 'plutocrats.'" He added that he's "not against" the idea of using roundness as a determining factor.
The IAU proposal will be voted on by IAU members Aug. 24.
"It all just might work," Marsden said.
110 - Jet in Columbus
Gonzo 108......... Uh huh
111 - Jet in Columbus
You know in a way it's a good thing. Major planets would be planets and the zillions of objects we don't necessarily feel worth bothering with or memorizing, would just be shoved in a folder marked "Plutons" and forgotten...
or is that an over simplification?
112 - Victor Plenty
Much as it might pain me to do so, I too must defend Richard's right to question the definitions set by the IAU (even though I find his specific reasons for questioning these particular definitions to be utterly irrational and fundamentally misinformed).
So, on this I have to agree with Duane. There is nothing sacrosanct about the IAU's definitions. Just as they can change the definition now, they could change the definition again if someone brings up good enough reasons for doing so.
I happen to agree with them on the need to settle on a better definition for what a planet is, but not because of blindly bowing down to their authority.
The old definition is too sloppy. Scientific definitions should not rely on tradition. A coherent definition ought to enable us to look at an object's properties and determine whether or not it's a planet, solely by reference to the definition. We should not need to know whether the object is on some officially recognized list of duly accredited planets, as accepted in the traditions of our grandparents.
Tradition might have been good enough when our instruments could barely tell Pluto even existed. Now that we are likely to find many objects much larger than Pluto, orbiting other stars as well as our own, we need a definition that is coherent, not just palatable to traditionalists.
There is plenty of precedent for doing things like this. For example, Ceres was defined as a planet soon after its discovery. Then, about 150 years ago, it was removed from the roster of planets and redefined as an asteroid. (Incidentally, Brodie is mistaken in several ways about what asteroids are and where they are, but this comment is already getting too long so I won't go into that.)
Is the proposal under consideration at the IAU right now the best solution to these issues? I'd have to say probably not, especially with the added complications of defining new entities like "plutons" and "double planets." But it is a step toward improving a situation which has been unsatisfactory for many years now.
113 - Jet in Columbus
Sorry guys, but I still say it an elegant and simple solution...
8-(possibly nine with one still out there beyond Xena) Classic planets, and then the rest are thrown in together as "Plutons".
Simple, we only have to deal with 8 or 9 and the rest are of passing unique interest, but don't have to be dealt with unless absolutely necessary.
Carus deus, quis have ego commissio?
Jet
114 - Jet in Columbus
Well, I was going to write an article about how the IAU was setting up a committee to search for Earth-threatening asteroids, but the data looked awful familiar, then I remembered I'd already written it!
115 - PoizonMyst
Its nice to see we are all in our usual jovial spirits ... debating over space with vigourous fervor :-P
I too have been watching the IAU website with great expectation of their final decision on the definition of a "planet" since the announcement of 2003 UB313's discovery. For years I have doubted Pluto's classification as a planet for a number of reasons - its off kilter orbit of the sun, it's comparitive size and binary orbit with it's "moon" Charon, its proximity to the Kuiper belt, and the discovery of several large "round" bodies within the belt that suggest to me Pluto is just another of these which had simply been knocked off course sometime in its ancient history, placing it just within the reaches of the "Classical Planets".
Personally I find the proposed solid "definition" by the IAU a little ambivilous also ... not that I can really do much about it, or have a better proposal. I think they are having an awful time trying to come up with something viable, which will make everyone happy and won't require much adjustment should further discoveries be made in the unforseen future to challenge the definition.
Firstly, there's Pluto's recognised historical significance as a "planet" - which if changed, as mentioned, would put astrologers readings out of whack (not that they arent already a good month out of whack anyway :-s) and offends those hard-heads who don't want to see Pluto's status "downgraded". Also, it changes the text-books ... but then that's what space exploration is bound to do anyway, isnt it? I own plenty of astronomy text books, less than ten years old, which are already obsolete for purely accurate information.
Then theres that damn discovery of UB313 ... everything was fine and dandy until that chunk of rock came along! We were all happy to go on oblivious to those "slightly smaller than Pluto" discoveries (like Quoar and Sedna) until UB313 had to go and wreck everything by being bigger than our beloved Pluto! Something was going to have to be done about defining such objects sooner or later. Really, they were popping up left right and centre ... it was only time until one larger than Pluto would rear it's ugly head. Anyone believing otherwise would be just a little naive. Personally, I was quite satisfied with the idea of "trans-Neptunian objects" and viewing Pluto for what it really is - a Kuiper Belt object gone walkabout which occasionally hangs out within the orbit of Neptune.
As for redefining Ceres as a "Planet" ... be it a "dwarf planet" (and that's not even part of the official definition) ... wtf is that? Ceres is a bloody asteroid! Albeit a big bastard, but it's so obviously part of the Asteroid belt. Bloody hell, when did that thing get thrown in the mix?
As for "Classical Planets" and "Dwarf Planets - oddly these two ideas are not actually planned as part of the definition - described only as historical and descriptive references. "Pluton" however is apparently given status as part of the "Planet" definition ... just to be PC I suppose. Should be interesting as to where a hypothetical Planet X the size of Mercury, or larger, would fall if discovered.
In this decision the IAU is never going to please everybody, or describe everything that could be out there, in one neat little dictionary definition. I even saw an interview with one pedantic twit who suggested the proposed IAU definition excludes Saturn as a "Planet" because it isnt "spherical" enough ... yes, well, we know he wasnt reading the press release correctly :-|
Obviously some people just cant handle change. But then, what can you do? The whole nature of new technology in space exploration is inevitably going to turn up more and more celetial objects that havn't been previously defined - just watching a couple of episodes of Star Trek (yes, I know there are lots of plot faults) should be enough to prepare us for unexplained weird shit in space.
Oops ... waffle on, waffle on.
116 - Jet in Columbus
Thanks PoisonMyst, I appreciate the update and the info.
As I've said before I like the decision, as it gives us 8 classic planets to deal with and the rest can be tossed in the "Junk drawer" of science called a "Pluton"
You imput was appreciated here
Jet
117 - Vern Halen
Planets, schmanets - I'd like to know know more about this Nemesis thing - the doppelganger to dear ol' Sol. Any more info about that out there?
118 - Jet in Columbus
Fair enough Vern, Use this link and scan half way down the page for "Planet X" information
119 - PoizonMyst
Jet 116
Yeh I don't mind the proposed definition either ... my only beef being the inclusion of Ceres 'cause it can't be placed in the junk "Plutons" category.
120 - Victor Plenty
Ceres has already been a planet and survived a "downgrade" to asteroid, as I've mentioned previously. It wouldn't hurt Pluto to go through the same thing, just as it wouldn't hurt the other planets to have Ceres join their little club. In some ways, Ceres is even better qualified for planet status than Pluto is. Ceres has an orbit that doesn't cross any other planetary orbits.
Quaoar and Sedna and Xena have weird orbits, so I can understand why people wouldn't want to think of them as planets. By comparison to them, Ceres is in a nearly circular orbit.
We will have to reach some agreement on how to pronounce Ceres, though. Is it "see-rees"? Or "sear-ees"? Or maybe "sare-us"?
121 - Victor Plenty
Small correction: Quaoar's orbit is actually a bit rounder than Ceres'. Sedna and Xena are the highly eccentric ones.
Still, both Ceres and Quaoar have orbits more like a standard planetary orbit than Pluto has. Not only are their orbits closer to circular, they are also closer to the plane of the ecliptic than Pluto's orbit.
122 - Jet in Columbus
Poison Myst-Well Ceres hasn't been studied all that closely so who knows? We may be surprised.
123 - Jet in Columbus
Thanks Victor. I for one am comfortable with Ceres as a planet because it isn't likely to break out of its orbit like asteroids are, which would the only addition to their definition that I would have added.
Carus deus, quis have ego commissio?
Jet
124 - Jet in Columbus
PS... I've been pronouncing it Seer-rus in my head
125 - Jet in Columbus
I've been pondering the origin of the Mars-sized planet that collided with Earch, carved out the Pacific Ocean, and formed the Moon.
In the order of my own personal likelyhood...
A. A planet that formed in our orbit opposite of the sun that slowly worked its way around to collide with us. This has the simplicity of not having to play with gravitational mechanics and interference with other planets.
B. A Huge asteroid from the belt- but how did it get here without interfering with Mars.
c. A space wanderer that was pulled in with the sun's gravity.
I sort of used to fantasize of a "mirror" Earth on the opposite side of the sun in our orbit that I called "Gypsy"
I've often wondered why we've never stationed a satelite in stationary orbit to watch the Earth go around the sun, possibly at the sun's north pole at say the distance of say 2-400 million miles.