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Thread: All the planets in a line

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    All the planets in a line

    Fairly stupid title, but I know that the astronomical terminology for this sort of thing can get pretty specific.

    I was just watching BBC stargazing live, and Brian Cox had a model of the Solar System with all the planets in a line on one side of the Sun, and jokingly said that this would happen in 2012, before hastening to remind the viewers that it was a joke.

    But I've always wondered, how long would it take for all 8 of the planets to form a line on one side of the Sun? I know that simultaneous transits of Venus and Mercury only happen once about every 2-300,000 years, so I imagine the timespan for a full lineup of the usual suspects must be pretty vast. Could it happen in the lifetime of the Sun? Or at least before the planets are ripped from their orbits?

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    That’s an interesting question that Jean Meeus addressed in three chapters of the first book in his Mathematical Astronomy Morsels series: http://www.amazon.com/exec/obidos/AS...514/crastro-20 .

    First we must ask what is meant by a line? The planets’ orbital planes exist in three-dimensional space and are slightly inclined to each other. So a true straight line would be impossible.

    So let’s assume what is meant is the projection of the planets onto a single plane such as the ecliptic. So we would be looking for all eight planets to share the same heliocentric longitude at the same moment. While that is theoretically possible, the probability of that for just three planets is zero. That is to say if absolute precision is required. So let’s allow for some tolerance. Meeus found that during the years 0 through 4000, the only example of a heliocentric sector as small as 40° containing all eight planets occurred on 1128 APR 11. If the tolerance were to be only 1°, Meeus calculated that all eight planets would lie in such a narrow sector once every 10˛˛ years.
    For astronomical graphics and data visit
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    I was watching this aswell so i googled to find out if or when this has ever happened based on probability they line up every 86 billion-trillion-trillion-trillion years!

    http://www.etsu.edu/physics/etsuobs/.../planalign.htm

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    And coincidentally, the year 2012 only happens once every 86 billion trillion trillion trillion years! Couldn't be a coincidence!
    As above, so below

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    If theplanets ever all lined up on one side of the Sun, the astrology buffs would fear the Solar System tipping over.

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    Quote Originally Posted by Jens View Post
    And coincidentally, the year 2012 only happens once every 86 billion trillion trillion trillion years! Couldn't be a coincidence!
    LOL! Nice

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    Quote Originally Posted by jens View Post
    and coincidentally, the year 2012 only happens once every 86 billion trillion trillion trillion years! Couldn't be a coincidence!
    omg where's the bomb shelter???

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    I remember someone saying such an event was supposed to happen in 2040.

    please tell me you guys are joking about all this, I don't wanna be scared after finally coming to terms with things.

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    Quote Originally Posted by Tenshu View Post
    I remember someone saying such an event was supposed to happen in 2040.
    please tell me you guys are joking about all this, I don't wanna be scared after finally coming to terms with things.
    Yes, we're joking. The answer is that it will never happen in the lifetime of the solar system. Actually, even if it did happen, it wouldn't mean anything anyway! Planets align all the time (once a year or more basically, the earth aligns with each of the planets.
    As above, so below

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    Still, just to be on the safe side . . . try to be in the Southern Hemisphere that week just in case it all does tip over.

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    It is obvious some take what is written here as serious., and true... and look to this forum of putting bad astronomy where it belongs...

    in a Trash can.. Lets be perfectly clear... NO. A alignment where all planets of the solar system are lined up has not happened and can not.

    Down-loading a astronomy program that lets you see the position of planets in any time frame you like are not hard to find...

    This is a none starter as a question... wipe the concern away... Has not., and can not happen.

    To further dispel your fears consider that the two large gas giants of this system did pass as closely as the distance from the sun allows.

    And apart from making a few good photo opportunities... nothing changed. No super volcanic action. No tectonic action... Nothing.

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    Quote Originally Posted by DonM435 View Post
    Still, just to be on the safe side . . . try to be in the Southern Hemisphere that week just in case it all does tip over.
    Or alternately, if you need to stay in the northern hemisphere for work or whatever, it would be best to buy a pair of shoes with suckers on the bottom to secure yourself so you don't fall off the earth.
    As above, so below

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    Quote Originally Posted by Tenshu View Post
    I remember someone saying such an event was supposed to happen in 2040.

    please tell me you guys are joking about all this, I don't wanna be scared after finally coming to terms with things.
    You’re referring to 2040 SEP 08 when as viewed from Earth the five bright planets and the Moon will all appear contained within a span of 9.3°. They will not be in an especially narrow heliocentric sector. Below is a preview graphic I created for the event as viewed after sunset in the western sky from Chicagoland.

    For astronomical graphics and data visit
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    Quote Originally Posted by astromark View Post
    It is obvious some take what is written here as serious., and true... and look to this forum of putting bad astronomy where it belongs...

    in a Trash can.. Lets be perfectly clear... NO. A alignment where all planets of the solar system are lined up has not happened and can not.

    Down-loading a astronomy program that lets you see the position of planets in any time frame you like are not hard to find...

    This is a none starter as a question... wipe the concern away... Has not., and can not happen.

    To further dispel your fears consider that the two large gas giants of this system did pass as closely as the distance from the sun allows.

    And apart from making a few good photo opportunities... nothing changed. No super volcanic action. No tectonic action... Nothing.
    I don't think anyone on this thread, least of all myself, has suggested that such an alignment is possible in the near future, or that it will have any ill-effects on Earth. If they have, it has been in jest. Given that the figures posted for such an alignment so far include 1022 years (excluding Pluto) and 1044 years (including Pluto) and that the mathematically predicted lifetime of our Solar System is no longer than 1015 years, it would appear that your statement about such an event not occurring in the lifetime of our Solar System is correct, which is all I wanted to know.

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    Quote Originally Posted by Centaur View Post
    You’re referring to 2040 SEP 08 when as viewed from Earth the five bright planets and the Moon will all appear contained within a span of 9.3°. They will not be in an especially narrow heliocentric sector. Below is a preview graphic I created for the event as viewed after sunset in the western sky from Chicagoland.

    It will look like God is firing a shot across the Sun's bow.

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    Quote Originally Posted by DonM435 View Post
    Still, just to be on the safe side . . . try to be in the Southern Hemisphere that week just in case it all does tip over.
    If we're lucky, it will tip over in the Fall, so we get to skip Winter!

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    Quote Originally Posted by Centaur View Post
    You’re referring to 2040 SEP 08 when as viewed from Earth the five bright planets and the Moon will all appear contained within a span of 9.3°. They will not be in an especially narrow heliocentric sector. Below is a preview graphic I created for the event as viewed after sunset in the western sky from Chicagoland.

    That would actually look pretty cool-- I hope I'm still around to see it in 29 years.

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    Recall "The Jupiter Effect" by John Gribben predicting major global catastophes resulting from the then future 1982 "alignment" of seven planets. That book, as badly inaccurate as it was, helped spur my interest in astronomy back in 1974.

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    John Gribbin (you may be thinking of Alan Gribben, who's been in the news for expurgating Huck Finn). Being a good scientist, he refudiated his work not long after (I can't recall whether it was before the "alignment" or after! ).

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    Being actively involved with the once a week public viewing at the local Observatory.
    This question of alignments has come up often... It should be noted that a optical alignment is not an alignment at all.
    The gas giants could be on the far side of the solar disk and appear to line up with Venus and Earth. You will note that in that image supplied of the 2040 chart. Mars and Venus appear together. Both must be on the far side of the disk from Earth. Earth is between them in a real alignment.

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    That's a good point, and since Mars is on the other side of the sun, it's not that bright at that time--at magnitude 2 it will be less bright than even Spica, a magnitude 1 star. Saturn will also only be a 1.

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    With billions of years left on the game clock, the planetary team hauls out an I-Formation? Not likely!

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    Yes, John Gribbin (not Gribben). He may have repented of bad science, but not before first publishing a follow-up book and then claiming Mt St Helens eruption being caused by the alignment that was yet 2 years from occurring. I suppose it isn't fair but I consider his writing in the same category as that of Whitley Streiber.

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    You do not believe us... fine. Download the programs and run the dates forward... I will wait for your apology.
    It just never actually happens. The Nine planets of Sol do never actually line up single file, ever.
    It's all pinned to the orbital period of each planet. Every few years Saturn and Jupiter pass one another.
    The trick being to get Uranus, Neptune and Mars to be in the same part of your sky. Venus and mercury would be in the daytime sky. Behind you.
    I have looked at several astronomy programs and factored in a few billion years... Not at any time do all the planets get to be within a 15 deg location line up.

    Unless of course you mean the 21st December 2012.. When the alignment is so tight the Earth will be ejected from the solar system and we all freeze to death... "Please ignore that evil comment... Lol"

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    Quote Originally Posted by Usher View Post
    Yes, John Gribbin (not Gribben). He may have repented of bad science, but not before first publishing a follow-up book and then claiming Mt St Helens eruption being caused by the alignment that was yet 2 years from occurring. I suppose it isn't fair but I consider his writing in the same category as that of Whitley Streiber.
    I have read a lot of Gribbin's books since, and they've been helpful. Perhaps he learned his lesson?

    Looking up the Jupiter Effect on wikipedia, it says that they published the follow up book in 1982, after the effect was to have taken place, backdating the theory to account for the 1980 eruption. Sheesh.

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    The planets sort of line up most every century. Are errors less than 30 million kilometers ok? Line up plus or minus one kilometer occurs about once per google years = essentially never. Neil

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    Quote Originally Posted by neilzero View Post
    The planets sort of line up most every century. Are errors less than 30 million kilometers ok? Line up plus or minus one kilometer occurs about once per google years = essentially never.
    googol

    Gaaah, I just discovered that (googling googolplex) that the Google corporate headquarters complex is called the Googleplex. Naturally.

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    First time that I tried to access Google (Good Grief, how long ago was that?) I innocently and correctly typed "googol.com" into the primitive software.

    I got to some math site, and the intro said something like "You probably want google.com. But if you're really interested in ... "

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    What are you all talking about? The planets are all in a line right now.

    *Pause*

    Oh, you meant a straight line! Oops, my bad.

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    This diagram of the solar system on 11 February 1524 is about as good as it gets. Only Earth and Uranus are out of orb.

    Jupiter, Saturn and Neptune align every 178.9 years in families of conjunctions that drift in and out of exact alignment. Checking all dates in multiples of 179 years before and after this diagram is an easy way to find alignments. Another family of alignments is centred on 769 AD.

    Software is http://dd.dynamicdiagrams.com/wp-con...rrery_2006.swf

    Planets 11 February 1524.gif

    ETA: And here is the solar system on 7 July 2020 when the visible planets are fairly well lined up on one side of the sun - 7 July 2020 planets.gif
    Last edited by Robert Tulip; 2011-Jan-30 at 04:01 AM. Reason: Add 2020

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