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Mercury -- Not Venus -- is the Closest Planet To Earth on Average, New Research Finds (gizmodo.com)

Posted by msmash on from the how-about-that dept.

That's the finding presented by a team of scientists who have published their results this week in an article in the magazine Physics Today. From a report: They explain that our methods of calculating which planet is "the closest" oversimplifies the matter. But that's not all. "Further, Mercury is the closest neighbor, on average, to each of the other seven planets in the solar system," they write. Wait -- what?

Our misconceptions about how close the planets are to one another comes from the way we usually estimate the distances to other planets. Normally, we calculate the average distance from the planet to the Sun. The Earth's average distance is 1 astronomical unit (AU), while Venus' is around 0.72 AU. If you subtract one from the other, you calculate the average distance from Earth to Venus as 0.28 AU, the smallest distance for any pair of planets. But a trio of researchers realized that this isn't an accurate way to calculate the distances to planets. After all, Earth spends just as much time on the opposite side of its orbit from Venus, placing it 1.72 AU away.

One must instead average the distance between every point along one planet's orbit and every point along the other planet's orbit. The researchers ran a simulation based on two assumptions: that the planets' orbits were approximately circular, and that their orbits weren't at an angle relative to one another.

177 comments

  1. Link to the Physics Today Article by mykepredko · · Score: 4, Interesting

    https://physicstoday.scitation...

    Interesting work with the best message to get out of this; don't rely on what's obvious, test what you think is true.

    --
    Mimetics Inc. Twitter
    1. Re:Link to the Physics Today Article by Hillie · · Score: 1

      This is pretty much how everything works nowadays.

      You see articles all the time that are talking about studies that were undertaken that prove all this stuff that is common sense. And they spent countless millions or what not on the studies..

      It's ridiculous. And most of it is all political.

      Instead of having studies to find out what's true, they have studies to confirm their desired outcome. And when it doesn't they sweep it under the rug.

      But the thing about this I find most interesting is.. There's errors being just discovered in how we calculate the distance of the planets... but we are so absolutely sure that Global Warming, err.. I mean Global cooling.. err. I mean Climate Change is going to kill us all in a few decades.

      --
      - Alex
    2. Re:Link to the Physics Today Article by Anonymous Coward · · Score: 0

      Yes, science is a liberal conspiracy.

    3. Re:Link to the Physics Today Article by Anonymous Coward · · Score: 0

      Same with education, law, economics, history... goddam Liberals have taken them all over like it's their jobs or something, like they even went to school and studied that. It's crazy! How can we trust that and not my gut instead?

      /fox news traitor

    4. Re:Link to the Physics Today Article by Hillie · · Score: 2

      Let me repeat myself for the retarded folks:

      Science: You have studies to figure out how something works or what outcome you get from a hypothesis

      Liberal pseudo-science: You rig studies in favor of coming out with your chosen outcome. If it doesn't you simply do not publish that study.

      Liberalism isn't a conspiracy, it's just fucking stupidity incarnate.

      So next time don't try to apply conspiracy theories to where there are none you hack.

      --
      - Alex
    5. Re:Link to the Physics Today Article by Anonymous Coward · · Score: 0

      Could you repeat yourself again for the even more retarded folks like me? You have two messages and they don't seem to be saying the same thing at all.

      To address a particular point in the original post: "studies that were undertaken that prove all this stuff that is common sense". There are all kinds of common sense things that turn out not to be true. Hot water can freeze faster than cold water. It's easier to send probes "up" to Jupiter than to "down" to Mercury. Light can travel in a vacuum (which was not a all common sense in the 19th century when all known waves were oscillations in a medium). It is a good idea to check common sense stuff out rigorously - we will learn things.

    6. Re:Link to the Physics Today Article by MachineShedFred · · Score: 4, Interesting

      Anybody that understands that all the planets aren't always in a single synchronized line could have inferred this - all the planets do not have the same orbital period, so there will always be a distribution around the Sun. This means that some of them may be on the opposite side of the Sun from us, and even though their average distance from the Sun is close to Earth's average distance from the Sun, they are not close to each other at that point in time.

      I didn't know there was opportunity for publishing papers that spell out common sense and grade school two-dimensional geometry, though.

      --
      Slashdot still doesnâ(TM)t support Unicode after it was added to the HTML standard in 1997.
    7. Re:Link to the Physics Today Article by Anonymous Coward · · Score: 0

      Liberalism isn't a conspiracy, it's just fucking stupidity incarnate.

      Progressivism, not liberalism. One of the currently popular mass deceptions is equating the two.

      Progressivism is absurd. Progressivism is based on the Theory of Progress whereby there is a necessary progression from any starting position to another with human well-being increasing every step of the way. The Theory of Progress entails that any change from the status quo to something not done in the past is inherently good because the progression is necessary. No other option could physically exist but change == good.

      It was made and became popular in the 1920's by extension of Marx's then already disproven theories on necessary advancement of socioeconomic forms. As if every form of government necessarily can only come from a specific type and will evolve to be another specific type.

      It's so bad and so obviously wrong that progressives have repeatedly removed references to it on wikipedia and whitewashed progress as a concept, but the original publications are still available on Jstor and many highly-regarded academic journals have plenty of contemporary articles rebuffing the whole damn framework. Pick whatever journal you find to be authoritative in the field and read works on the Theory of Progress and it's political manifestation.

    8. Re:Link to the Physics Today Article by careysub · · Score: 1

      Interesting work with the best message to get out of this; don't rely on what's obvious, test what you think is true.

      Yes, testing common sense systematically is a valuable undertaking that will always get blow-hards here opining that "so what, it is obvious/unimportant/blah-blah".

      But my intuition for this question would have been Mercury since it is so close to the Sun, on the far side of its orbit it would never get as far away as Venus would, even if it never gets as close on its closest approach.

      --
      Starships were meant to fly, Hands up and touch the sky - Nicky Minaj
    9. Re:Link to the Physics Today Article by nickersonm · · Score: 1

      Apparently there's an opportunity for publishing 2D geometrical trivial-proof-by-simulation, even!

    10. Re: Link to the Physics Today Article by Anonymous Coward · · Score: 0

      You forgot religion, the other side of the liberal pseudoscience, but for Republicans: you say what you want to be true, then you find "scriptural evidence" to prove it, and of it's not there just make something up.

      For example, global warming is not part of God's plan, therefore it won't happen no matter what you do. You have free will but only enough to follow the plan.

    11. Re:Link to the Physics Today Article by Anonymous Coward · · Score: 0

      Seriously.

      Semantic games are not a great starting point for a scientific paper. Super weak.

    12. Re:Link to the Physics Today Article by tehcyder · · Score: 1

      Liberal pseudo-science: You rig studies in favor of coming out with your chosen outcome. If it doesn't you simply do not publish that study.

      No, sorry, you need to explain again why this isn't a paranoid conspiracy theory.

      --
      To have a right to do a thing is not at all the same as to be right in doing it
  2. gassy atmosphere by Anonymous Coward · · Score: 0

    Which planet is closest to ur anus?

    1. Re:gassy atmosphere by Anonymous Coward · · Score: 0

      I think Mons Veneris is on Mars?

    2. Re:gassy atmosphere by Anonymous Coward · · Score: 0

      My penis, most of the year. The summer is quite unpleasant for my taint as it is stretched across the solar system.

  3. You are technically correct. by Anonymous Coward · · Score: 0

    The best kind of Correct.

    1. Re: You are technically correct. by Anonymous Coward · · Score: 0

      You are correct math is hard!

      Avg closest âoeseenâ in the sky...
      Moon
      Sun
      Mercury
      Venus
      Etc

      Closest by short distance possible
      Moon
      Venus
      Mercury
      Mars
      Etc

      Now short out only planets (Pluto is a planet!!)

      Set theory next!

    2. Re:You are technically correct. by jellomizer · · Score: 1

      The issue is one of scale.
      We are often shown our Solar System, with an inaccurate scale. Mostly so we can see the order from the sun.
      This article, is kinda of an Oh-Yea that makes sense to me, but I never really though about the average closest planet, I always think in terms of closest possible.

      --
      If something is so important that you feel the need to post it on the internet... It probably isn't that important.
    3. Re:You are technically correct. by fahrbot-bot · · Score: 3, Funny

      The best kind of Correct.

      You're obviously not married.

      --
      It must have been something you assimilated. . . .
  4. Hitting the burners a bit hard by SuperKendall · · Score: 0

    Scientist: Hey guess what, turns out Mercury is really closer to the Earth, even though it orbits closer to the sun than Venus *snickers a bit*.

    Me: Well, Ok, I guess maybe if you consider speed of rotation around the sun it technically is closer more often but...

    Scientist: *leans way over beaker and takes a bit whiff* In fact... Mercury is closer to all the planets!! *eyes glaze over scientist slumps on floor*

    Me: Pours contents of beaker over prone scientist, storms out of room.

    --
    "There is more worth loving than we have strength to love." - Brian Jay Stanley
  5. Don't be a smartass by Anonymous Coward · · Score: 0

    You're being a smartass.

  6. I call bullsht by mestar · · Score: 0

    If perfectly circular, average distance from any planet to any planet should be equal to the center of their path circle, which is, drum roll please, the center of the sun.

    So, Earth-Mercury average distance shares the first place with any other of 45 planet pair combinations.

    1. Re:I call bullsht by Anonymous Coward · · Score: 0

      Pro tip: orbits arent circular, or Kepler would have had a much easier time of it.

    2. Re:I call bullsht by Anonymous Coward · · Score: 0

      While I think your subject is correct, your reasoning is not. They are computing the average actual distance between the planets over time. Not the average distance between their orbits, which is what you are doing. Since the planets have different years, they will be all over the place. I think if all the planets have the same years, then you would be correct.

      But I would think that you could just set up an integral equation to calculate this, and then if you couldn't do it precisely, you should be able to bound it as accurately as you would like. No need for any simulation. You would however, need to specify a time interval. Since by carefully selecting a start and end time for your calculation, I would think you can get almost any answer you would like.

      So this just sounds like some grad students playing with a computer and then publishing the results. Why would you even start with the circular assumption. It's known to not be true, and using ellipses wouldn't be much harder. I'm guessing the magazine isn't really an academic journal. Otherwise, publishing this article makes no sense what so ever.

    3. Re:I call bullsht by abies · · Score: 3, Interesting

      If perfectly circular, average distance from any planet to any planet should be equal to the center of their path circle, which is, drum roll please, the center of the sun.

      No? Planet A at 1AU orbit and Planet B at 2AU orbit have distance between 1AU and 3AU. Planet C at 1000AU has distance to planet A between 999AU and 1001AU. Whatever are their periods, some average of 1-3 won't get anywhere close to average of 999-1001.

      So, Earth-Mercury average distance shares the first place with any other of 45 planet pair combinations.

      Not sure how you came up with number 45. 8 planets give 28 combinations, so it should be 'any other of 27 combinations'. Even if you didn't get memo from 2006 about Pluto, it would be 36-1=35 combinations.

    4. Re:I call bullsht by aardvarkjoe · · Score: 1

      If perfectly circular, average distance from any planet to any planet should be equal to the center of their path circle, which is, drum roll please, the center of the sun.

      So, Earth-Mercury average distance shares the first place with any other of 45 planet pair combinations.

      Reading through the article, they're doing something where they are considering the position of a planet to be "a uniform probabilistic distribution around a circle defined by the average orbital radius". It's not clear exactly how that distribution is defined, but depending on how that was done, it seems possible that the distance calculated could be different than the distance from the Earth to the sun.

      There's no explanation that I can see on why they would believe that assumption of distribution to be a good one in the first place, though; if they did some research that led them to that assumption, that is probably more interesting than their "closest planet" result.

      --

      How can we continue to believe in a just universe and freedom to eat crackers if we have no ale?
    5. Re:I call bullsht by jschultz410 · · Score: 1

      Are you trying to say that the average distance between two planets should be whatever the distance is of the further planet to the center of Sun? That the circular orbit of the inner planet effectively cancels itself out in terms of varying distance and can be modeled as sitting at the center of Sun with no passage of time?

      That might be true, but then the average distance between Jupiter and Earth versus Saturn and Earth would still be quite different, with Saturn being further.

      Beyond that, the planets orbit Sun at different rates and I'm not sure the inner planets varying distance will perfectly cancel itself out. They actually simulated this and did a time average.

    6. Re:I call bullsht by Anonymous Coward · · Score: 1

      Pro tip: that doesn't significantly change the conclusion that mestar arrived at.

    7. Re:I call bullsht by jschultz410 · · Score: 1

      Right. You might be able to argue that the inner planet's orbit cancels itself out and can be modeled as sitting at center of Sun. I'm not sure that's true, but the OP's argument that all planets are on average right on top of each other is obviously wrong.

    8. Re:I call bullsht by Rolgar · · Score: 1

      But we can also compare to the average distances of all of Earth's which is also the center of the Sun and find the distance is 0.

      Or you can realize that given one point of Earth's orbit, compared to all of Venu's v Mercury's locations will usually results in Mercury for two reasons. Consider when both Mercury and Venus are both perpenducilar to the line between the Earth and Sun. The distance between Earth and Mercury is approximately 160,465,000 and Earth and Venus is 184,835,000. (Using the pathagorian theorum and the average distances between the Sun and each planet). Considering at the two points in the middle of the orbit relative to Earth's position, Mercury is close, you're likely to find that Venus spends more time farther away from the Earth than Mercury.

      Of course, what most people consider most interesting is what is the closest approach between any two bodies, and Venus is by far the closest by this measure.

    9. Re:I call bullsht by Solandri · · Score: 4, Insightful

      perfectly circular, average distance from any planet to any planet should be equal to the center of their path circle, which is, drum roll please, the center of the sun.

      No. Distance is a scalar, not a vector. So the average distance doesn't work out to the center of the sun. It works out to the the sum of all points along the circular orbit. For Venus' case, since its orbit is bigger, the scalar distance to each equivalent point in Mercury's orbit is on average bigger because it's at a greater angle from the Earth (with Earth-to-sun line being the shortest distance).

      e.g. Pretend Mercury is located in the sun, and Venus has the same orbit as Earth. Consider four points on each orbit spaced 90 degrees apart.

      • When Earth, Venus, and Mercury are in line with the sun all on the same side, Mercury is as far as the sun from the Earth (call it R), Venus is on top of the Earth, so its distance is zero.
      • When Venus and Mercury are on opposite sides of the sun from Earth, Again, Mercury is distance R, Venus is 2R.
      • When Venus and Mercury are at 90 degrees to the right of the sun from Earth, this creates a 45 degree right triangle. Mercury is still at R, Venus is at 2sin(45)R, or 1.414R.
      • Likewise when Venus and Mercury are at 90 degrees to the left of the sun, you have the same 45 degree right triangle flipped. And Mercury is at R, Venus is at 1.414R.

      Average these four points. The first two cancel out (both average a distance R). The second two result in Mercury being at distance R, Venus at 1.414R. And hence Mercury is on average closer than Venus, even though we're pretending Venus has the same orbit as the Earth.

    10. Re:I call bullsht by jschultz410 · · Score: 1

      Thank you for that insight! I was wondering if the average distance between, say, Neptune and all the inner planets would all be the same / similar (i.e. - if an inner planet's orbit effectively cancelled out it's varying distance and could be modeled as sitting at center of Sun). Your point is, no -- it wouldn't, even without bringing time varying orbit distortions into the picture.

    11. Re:I call bullsht by jgtg32a · · Score: 1

      If the orbits were circular we would be talking about Tycho Brahe instead.

    12. Re:I call bullsht by K.+S.+Van+Horn · · Score: 1

      You're wrong, because we're looking at average distance between Earth and another planet, NOT the distance between the average positions of Earth and another planet. You need to learn about Jensen's Inequality:

      http://bayesium.com/its-all-ab...

    13. Re:I call bullsht by Anonymous Coward · · Score: 0

      If perfectly circular, average distance from any planet to any planet should be equal to the center of their path circle, which is, drum roll please, the center of the sun.

      No. Simple trigonometry will show you that the average distance to points on a circle from a point outside the circle is longer than the distance from that point to the centre of the circle. The only points that will average out to the centre are those on a direct line from the point outside the circle through the center of the circle. Any other pair of diametrically opposed points on the circle will average out to a longer distance.

    14. Re:I call bullsht by habig · · Score: 2

      There's no explanation that I can see on why they would believe that assumption of distribution to be a good one in the first place, though; if they did some research that led them to that assumption, that is probably more interesting than their "closest planet" result.

      They did. To quote:

      The PCM treats the orbits of two objects as circular, concentric, and coplanar. For our solar system, that’s a pretty reasonable assumption: The eight planets have an average orbital inclination of 2.6 ± 2.2, and the average eccentricity is 0.06 ± 0.06. An object in a circular orbit maintains constant velocity, which means that over a sufficiently long period, it is equally likely to be in any position in that orbit.

      Then, they pull out an ephemeris and actually integrate the distances from time point to time point, and that answer is within 1% of their "circles" estimate.

    15. Re: I call bullsht by Anonymous Coward · · Score: 0

      This article is blatantly flawed. As already pointed out, planetary orbits aren't circular, so the simulation is trash. Instead of making false statements like this article has done, a two dimensional graph should be made showing direct 3D distances between any two planets over the course of the longest orbit. One graph should be made between Earth and all the other planets. A second graph should be made between Mercury and all the other planets.

    16. Re:I call bullsht by WorBlux · · Score: 2

      Not true, as trigonometric functions aren't linear. Do the math. Take venus at a right angle orbit to earth. sqrt(1+0.728^2)= 1.234 AU. Then Take Mercury at the same right angle, sqrt(1+0.39^2) = 1.073 AU. Mecury is closer for at least half of it's orbit.

      But a weird thing is that by average closest planet, they don't mean average distance is the least, they mean if you pick a random time, it's most likely that at that moment, mercury will be closer than mars or Venus. The result was about 45% Mercury, 35% Venus, and 20% mars.

    17. Re:I call bullsht by WorBlux · · Score: 2

      Actually they did calculate average distance as well. 1.05 for mecury, 1.15 venus, 1.65 mars

    18. Re:I call bullsht by ceoyoyo · · Score: 1

      You quoted the sentence that tells you precisely how the distribution is defined: it's a uniform distribution (same value everywhere) over the perfect circle that is their approximation of the planet's orbit.

      The distribution of a planet's location is not uniform for elliptical orbits. Copernicus's second law is more or less a statement of the actual relation: an orbit sweeps out equal areas in equal time. You can convert that into a speed at each point in the orbit, and the actual probability distribution is the normalized inverse of the speed (you're more likely to find the planet at parts of the orbit where it's moving more slowly).

      For a perfect circle, which they assume, equal areas in equal time means uniform speed, so uniform distribution.

    19. Re:I call bullsht by rtb61 · · Score: 1

      As human social development proceeds and we slowly but surely leave the mud monkey (earth primate) transitional stage, a lot of this persnickety astronomical stuff takes greater precedence. So the definition between the closest planet at any one time and the closest planet on average and the closest orbiting planet and as such the fastest planetary trip at any specific time and whether you travel in the direction of orbit or the opposite direction, to arrive there, taking into account acceleration and deceleration capabilities, all has much greater meaning and importance.

      For most of us planetary travel times all a little arbitrary but in one hundred years, that travel time and arrivals and departures will all become a lot more interesting for everyone.

      --
      Chaos - everything, everywhere, everywhen
  7. Distance doesn't matter by jeti · · Score: 2

    It's all about the delta-v.

    1. Re:Distance doesn't matter by jschultz410 · · Score: 1

      Time doesn't matter?

    2. Re:Distance doesn't matter by green1 · · Score: 1

      And this is the truth. In reality, a space mission is unlikely to ever be planned to coincide with when a planet is hardest to reach, so AVERAGE distance is irrelevant. The only 2 things you care about are the thrust required, and the time it will take to get there, so closest distance is relevant, average not as much.

    3. Re:Distance doesn't matter by WorBlux · · Score: 1

      What planet is easiest to send a spacecraft to? Is not exactly the same question as "What planet is at this moment closest to us?"

    4. Re:Distance doesn't matter by Anonymous Coward · · Score: 0

      Not really. Explain how time matters to two missions to two different destinations that have the same delta-v.

    5. Re:Distance doesn't matter by dougTheRug · · Score: 1

      and "distance" from an orbital perspective, not a line-of-sight

    6. Re:Distance doesn't matter by jschultz410 · · Score: 1

      Say one mission takes 5 years while the other takes 1000 years.

      That might matter to the astronauts on board, the people funding the trip, etc.

      You've minimized the energy involved, but that's not the only consideration.

    7. Re:Distance doesn't matter by Anonymous Coward · · Score: 0

      Not even close - is it easier to chase down someone who's 20 meters away from you now, but running almost directly away from you; or moving to intercept a guy that is 100 meters away from you now but will pass within 30 meters from you?

      Easiest to get to equates to easiest to intercept. Planets actually move darn fast and I'd rather not be chasing one even if it's the closest *now*.

  8. Depends on your definition of closest by Anonymous Coward · · Score: 0

    April Fools day is still a few weeks away.

    As I see it, the closest planet to a reference planet is the planet whose semi-major axis length is nearest to that of the reference planet. The definition that these 'physicists' use is just plain silly, even sillier than the current definition of 'planet'.

  9. Seriously? by Dahlgil · · Score: 1

    I've had people ask me which planet is the closest one to Earth. I now stand corrected. I will now tell them that the order of the is Venus, Mercury, Earth, Mars, etc. and be properly geocentric about it.

    1. Re:Seriously? by jellomizer · · Score: 1

      No you can be far more annoying, and ask them?
      On Average? Or when the orbits reach their closest points? Or When orbits reach the furthest points?

      For some reason I have hard time making friends.

      --
      If something is so important that you feel the need to post it on the internet... It probably isn't that important.
    2. Re:Seriously? by Gavagai80 · · Score: 1

      When you ask whether object x is closer than object y, you obviously want to know which is closer right now, not on average. If you haven't memorized the current orbital positions of the planets, just be honest and tell them you don't know.

      --
      This space intentionally left blank
  10. I thought we knew this? by Anonymous Coward · · Score: 0

    I thought we already knew Mercury was the closest?

  11. On average THIS YEAR by the_skywise · · Score: 0

    Eventually Venus' orbit will "sync" with Earth's for awhile and Venus will be closer "on average".
    Really though - does this minutiae (which is easily statistically available) count as research? This is more like internet trolling about who's the better captain on Star Trek.
    Worst research, evah!

    1. Re:On average THIS YEAR by Anonymous Coward · · Score: 0

      This is more like internet trolling about who's the better captain on Star Trek.

      As long as we all acknowledge that Sisko is empirically the best. He is the only one to punch Q in his smug face.

    2. Re:On average THIS YEAR by mark-t · · Score: 1

      No... Venus might be closer than Mercury at their respective closest, but Venus is also further away from Earth than Mercury at their respective furthest because Venus' orbital radius is more than double that of Mercury. On average, it ends up that Mercury is the closest planet to Earth. It is also, not coincidentally, the closest planet to all the other planets as well... at least on average, over the entire lifetime of their respective orbits.

      --
      File under 'M' for 'Manic ranting'
    3. Re:On average THIS YEAR by jschultz410 · · Score: 1

      I think the point the OP was trying to make is that Venus "lingers" at its closest distance to Earth longer than it does at its furthest distance due to their relative motion around the Sun. That is, from the perspective of Earth, Venus moves relatively fastest when it is at its furthest distance, while it moves relatively slowest at its closest distance.

  12. Seems overly simplified again by majorwoo · · Score: 1

    So, they pointed out that the current way of calculating is oversimplified and then made some (potentially rather large) assumptions of their own?

  13. That's no moon by Mr_Blank · · Score: 1

    Eventually Earth's moon will be a dwarf planet. Then the closest planet will be The Moon.

    https://www.universetoday.com/...

  14. Obvious to anyone who observes them by jfdavis668 · · Score: 4, Interesting

    Amatuer astronomers love to observe Mars. The problem is Mars is on a close, but outside orbit. Unlike Jupiter and Saturn, which the Earth passes every year in thier orbits, it is a different story with Mars. It is only really close for two months every 2 years. It spends most of its time on the far side of its orbit until the Earth can chase it down again, and then quickly races away. Even though you can view it through most of its orbit, it is small and normally far away. Venus, even when near the far side of its orbit, it is fairly easy to observe. At least once it rises far enough out of the Sun's glare. Mercury would be even better, but due to the small orbit it doesn't get far from the Sun from our point of view before it dives back down into the glare.

    1. Re:Obvious to anyone who observes them by Anonymous Coward · · Score: 0

      Amatuer astronomers love to observe Mars.
       
      Seriously? I do volunteer work with amateur astronomers. Scores, if not hundreds of different ones each year. Aside from the brightening of Mars during opposition this past year I rarely even hear it mentioned as a target of interest. Even during opposition it was a dud because of the dust storm that arose.
       
      If you have access to a serious refractor you might have something to look at but even viewing it through an 11" f/10 that I have access to leaves a lot to be desired.

    2. Re:Obvious to anyone who observes them by dissy · · Score: 2

      It is only really close for two months every 2 years. It spends most of its time on the far side of its orbit until the Earth can chase it down again, and then quickly races away.

      It's because of this that make some interesting "artifacts" show up when plotting the path of Mars from the point of view on Earth when doing so on a 2d "map" of the night sky.

      On such a map, one sees Mars following a line as one would expect, then that path curves back around and it looks as if Mars is orbiting in the opposite direction for a time (roughly those two months), before it loops back around to continue in the original direction but along a path slightly offset from the original "tail" for the rest of those two years.

      If instead your 2d map is from the point of view of a hypothetical camera view above the plane of the solar system but with Earth at the center of that map, the orbit of Mars would plot out with these loops such that it looks like the line was drawn with a Spirograph.

      Every two years you get one of these misaligned circles containing a two month backwards loop in it.
      Just like with Spirograph if you keep going around, that is multiple orbits around Earth, you get the famous Spirograph "flower", or loopy loop (technical term) pattern.

      Amatuer astronomers love to observe Mars.

      The above does cause unfortunate timing issues for amateur astronomy too.
      Not only do you want to catch it during those two months while it is closest to Earth, but each two year period brings Mars close to a different vantage point on the Earth.

      Presuming as an armature you are not going around Earth to chase this ideal view and instead are waiting for it to happen overhead where you are at, you have to not only wait for the right two month period it is close, but also the right two year period it is closest to where you are looking from.

      Fortunately this pattern repeats on a scale that is just under 20 years or so, but assuming you live most of your life in the same place on Earth, this does limit the number of opportunities is a single lifetime to catch the ideal position of Mars to observe.

      Unfortunately for my experience the "ideal" view was different only in that I could see there were different shades of color compared with the usual smudged spec of blur.
      That was back in the late 80s and I haven't personally had another opportunity since, so I'm very thankful for all the amazing professional imagery from far superior sources that are so easily available to see today.

    3. Re:Obvious to anyone who observes them by jrumney · · Score: 1

      Presuming as an armature you are not going around Earth to chase this ideal view and instead are waiting for it to happen overhead where you are at, you have to not only wait for the right two month period it is close, but also the right two year period it is closest to where you are looking from.

      You'd think if we had armatures for the Earth we would have figured out how to rotate it so everyone can get a look during those two months by now...

  15. My prediction by necro81 · · Score: 3, Funny

    Well, shit, I need to recalculate my horoscope again.

    1. Re:My prediction by Anonymous Coward · · Score: 0

      This is the dawning of the age of asparagus.

    2. Re:My prediction by thegarbz · · Score: 1

      Mars is closer to the earth than you thought, and you will still die alone surrounded by cats.

    3. Re:My prediction by igny · · Score: 1

      Yeah, next thing we find out is that Proxima Centauri is not the closed star to us at all...

      --
      In theory there is no difference between theory and practice. In practice there is. - Yogi Berra
  16. The sun is even closer on average by Anonymous Coward · · Score: 0

    Take your useless metric and shove it were the daystar don't shine.

  17. By the same argument ... by jschultz410 · · Score: 1

    I'd bet that all of the solar system's planets are closer to Sun than they are to any other planet.

    1. Re:By the same argument ... by jythie · · Score: 1

      That is kinda the idea yeah.

    2. Re:By the same argument ... by Anonymous Coward · · Score: 0

      The distance from Venus to the sun is shorter than the distance from Venus to Earth, but the distance from Earth to the sun is identical to the distance from Earth to Venus. On average that is.

    3. Re: By the same argument ... by Anonymous Coward · · Score: 0

      No, Earth is closer to Sun than Venus on average. The near-far component of Venusâ(TM)s distance to Earth averages out to the center of Sun. But itâ(TM)s left-right component does not.

  18. Order of Orbits vs Distance by KalvinB · · Score: 1

    The order of the planets people think of is based on their orbiting distance from the sun.

    We resolved the whole geocentric vs heliocentric model of the solar system long ago.

    Figuring out the actual distance between the planets is useful information if you want to figure out the shortest distance to get from one planet to another.

    If Mercury is close to the other planets, it may be beneficial to get to there rather than to Mars.

    --
    Work Safe Porn
    1. Re: Order of Orbits vs Distance by Wycliffe · · Score: 1

      If Mercury is close to the other planets, it may be beneficial to get to there rather than to Mars.

      Not really. The only reason that the average distance between Mercury and the other planets is shortest is because the distance is shorter when Mercury is on the far side of the sun so you would need to travel thru the center of the sun to traverse this path. It would still technically be the shortest also by going around the sun but I canâ(TM)t think of a scenerio where stopping at Mercury first on the way to a planet on the far side really makes sense unless it was to take advantage of a free ride on their faster orbit around the sun to reach the backside.

    2. Re:Order of Orbits vs Distance by danbert8 · · Score: 1

      If Mercury is close to the other planets, it may be beneficial to get to there rather than to Mars.

      If you could travel to planets as the light flies, perhaps. What matters when traveling is not the straight line distance, it's the delta-v. Mars is much closer in delta-v to earth, thus is it easier to get to. Venus is the closest planet in delta-v, so it's the easiest to travel to.

      https://external-preview.redd....

      --
      Yes it's an anecdote! Were you expecting original research in a Slashdot comment?
  19. comment subject: by Anonymous Coward · · Score: 0

    Yes, and Sol revolves around the Earth.

    Unless you're part of the human collective that has accepted a heliocentric model for centuries.

    LOL I DON'T MOVE THE SPACE STATION MOVES AROUND ME

  20. So, pre-Kepler? by Actually,+I+do+RTFA · · Score: 1, Interesting

    It's not "research". They ran a simulation and reported the results. Which isn't interesting because the simulation was stupid.

    p>They assumed a fucking circular orbit (because the extra 1 parameter for an ellipse was too damn much). Which is something that Kepler disproved in the 1600s (and became an immortal name because of it.)

    Also, this assumes planets are co-planar (they aren't)

    Also, it's meaningless. When people talk about "our closest neighbor", they mean the one easiest to get to. So we want to know the closest point of approach, not "average". Making up a useless measure and publishing it isn't science.

    --
    Your ad here. Ask me how!
    1. Re:So, pre-Kepler? by Anonymous Coward · · Score: 1

      Kepler was also wrong. The orbits aren't ellipses.

      Close, but not technically correct. And, as it turns out, that error is becoming more and more important.

    2. Re:So, pre-Kepler? by Surak_Prime · · Score: 1

      It's not meaningless. Look, in absolute terms, yes, Venus gets closest to us. But, if you're planning a permanent settlement that is going to need to be resupplied several times a year, it might be more useful to put that settlement someplace that gets close *several times a year*, even if that isn't as close as Venus gets once in a while.

      --
      :::The Spear in the heart of the Other is the Spear in the heart of You; You are He - Surak of Vulcan:::
    3. Re:So, pre-Kepler? by Arnold+Reinhold · · Score: 1

      The study is meaningless. Any advantage of Mercury being closer to Earth several time a year is completely overwhelmed by how deep Mercury is in the Sun's gravity well. In fact spacecraft that have gone to Mercury have had to perform one or more flybys of Venus to lower their potential energy. It takes a long time and much clever astrogation to get to Mercury with the rockets we have.

    4. Re:So, pre-Kepler? by CastrTroy · · Score: 1

      Yes, but in terms of being a settlement, only Mars makes sense as Venus and Mercury are both way too hot to be anywhere close to hospitable. Mars, despite being further away has many qualities that make a good candidate for a permanent settlement.

      --

      Anthropic principle: We see the universe the way it is because if it were different we would not be here to see it.
    5. Re:So, pre-Kepler? by Anonymous Coward · · Score: 0

      "Easiest [planet] to get to" would have to be based on the energy you have to expend to get there. Most of that would, I assume, go to changing delta-vee. We could perhaps leave out getting into Earth orbit from the calculation because that's the same for every destination planet.

      Feel free to correct me, IANAA.

    6. Re:So, pre-Kepler? by SEE · · Score: 5, Informative

      Actually, they did pure math with those simplifying assumptions first. Then they ran a simulation using the actual orbital characteristics (PyEphem uses the real orbits) to check.

      That simulation then demonstrated that the assumptions in the pure math produced an error of under 1% for relations among the major planets.

    7. Re:So, pre-Kepler? by Surak_Prime · · Score: 1

      Possibly. My point wasn't that it would be a *decisive* factor to consider, only that is IS a factor to consider, and that's why it isn't "meaningless" as was asserted. And there may be other mission profiles aside from colonization where it *would* be decisive.

      As an aside, personally, I'd prefer to see us colonize a station or stations at Lagrange points, and then the Asteroid Belt, if at all possible - why put yourself back into another gravity well when you've already paid the heavy (literally) cost to get your people and your resources out of one? At least to begin with...

      --
      :::The Spear in the heart of the Other is the Spear in the heart of You; You are He - Surak of Vulcan:::
    8. Re:So, pre-Kepler? by Anonymous Coward · · Score: 0

      It's common to make simplifying assumptions, especially when the tossed variables don't have a significant impact. I'm unsure why you mention ellipses as if that's the only consideration. Have you calculated the eccentricity of those ellipses? The planetary orbits are nearly perfect circles, with the deviation only being a small fraction due to large scale we're talking about. Therefore it's common to just go with the assumption the orbits are perfectly circular because it doesn't make a significant impact with this type of experiment. We aren't calculating the path needed to land a probe or the exact date and time the planets will be viewable from Earth for the next 1000 years.

      Also, what is meaningful depends on the context. Not every goal will require the same data set. Just because it's meaningless to you doesn't mean it's meaningless for everyone else. Every piece of knowledge provides a building block for better understanding our Solar System and for advancing science. Stop talking in absolutes. Opinions and facts aren't the same thing.

    9. Re:So, pre-Kepler? by Tablizer · · Score: 1

      When people talk about "our closest neighbor", they mean the one easiest to get to.

      But Travelocity charges more for Venus.

      --
      Table-ized A.I.
    10. Re:So, pre-Kepler? by dougTheRug · · Score: 1

      you mean, because it's an n-body problem and not just the sun with the mass? Or... wut

    11. Re:So, pre-Kepler? by Anonymous Coward · · Score: 0

      Given the accuracy NASA/etc like or even need, I'll suppose the akshually is n-body - I imagine Jupiter being "in alignment" or whatever can drag out a skew that affects a no-thrust drift you want to do for months, yet arrive on point.

    12. Re:So, pre-Kepler? by Impy+the+Impiuos+Imp · · Score: 1

      That and relativistic precession.

      --
      (-1: Post disagrees with my already-settled worldview) is not a valid mod option.
    13. Re:So, pre-Kepler? by Impy+the+Impiuos+Imp · · Score: 1

      And running a sim would just asymptotically approach the actual average distance. But doing the math to calculate that value is much cooler.

      --
      (-1: Post disagrees with my already-settled worldview) is not a valid mod option.
    14. Re:So, pre-Kepler? by jschultz410 · · Score: 1

      Mars is a dustball that looks to have little to no natural resources making it attractive. It's only advantage is that it has an appreciable gravity, which is actually a double edged sword. I'd think colonies on Moon, in the belt, and other moons would make more sense. Also, the shaded zone of Mercury could be quite nice. You'd have a huge amount of solar power easily available.

      The vast, vast, vast majority of humanity will remain on Earth until if/when we can leave the solar system and seed the galaxy.

  21. The sun is the center of all planetary orbits by gurps_npc · · Score: 1

    The average location should always be the center of the orbit.
    The planets orbit the sun, so that should be their average location.

    QED, shouldn't all planets be be equally close?

    --
    excitingthingstodo.blogspot.com
    1. Re:The sun is the center of all planetary orbits by Anonymous Coward · · Score: 0

      On the scale of the Milky Way galaxy (let alone the entire universe) the planets are practically right on top of each other!

    2. Re:The sun is the center of all planetary orbits by jschultz410 · · Score: 1

      Think about two planets on the same solar orbit but opposite one another. They will always be the diameter of their orbit apart from one another. Not whatever distance you are referencing here (zero?).

      I think there is something to the idea that the orbit of the inner planet's varying distance might "cancel itself out" and could be modeled as sitting at the center of Sun. Even then though, the distance between Jupiter and Earth will be smaller than the distance between Neptune and Earth.

      But I'm not even sure if the orbit of the inner planet will nearly cancel itself out or do something else strange as all the planets orbit at different rates.

    3. Re:The sun is the center of all planetary orbits by Dunbal · · Score: 1

      Except orbits are elliptical. There's nothing in the center of the orbit, and the sun is at one of the foci...

      --
      Seven puppies were harmed during the making of this post.
    4. Re:The sun is the center of all planetary orbits by Dunbal · · Score: 1

      And on average the spiral arm next to us is closer to us than the entire rest of our spiral arm. Send grant money please.

      --
      Seven puppies were harmed during the making of this post.
    5. Re:The sun is the center of all planetary orbits by Headw1nd · · Score: 1

      No. Consider the problem from a single point on the orbit of the outer planet. For our coordinates we can set the x-axis running from the sun to the outer planet, and the y-axis perpendicular in the plane. From this position, we can consider every point along the inner planet's orbit equally likely. If we were only looking at the x component of the average distance from the outer planet to the inner planet, you would be right, as it equals the distance from the outer planet to the sun, but there is a y component as well. Together they mean the average distance between the planets is always more than the distance to the sun.

    6. Re:The sun is the center of all planetary orbits by Anonymous Coward · · Score: 0

      Orbits aren't elliptical.

    7. Re:The sun is the center of all planetary orbits by WorBlux · · Score: 1

      No if parallax shift between the bodies is significant, than you can't base average distance off of average location, as trig functions aren't linear.

    8. Re:The sun is the center of all planetary orbits by iggymanz · · Score: 1

      You're disagreeing with Kepler's first law? Do tell...

    9. Re:The sun is the center of all planetary orbits by Anonymous Coward · · Score: 0

      > You're disagreeing with Kepler's first law? Do tell...

      https://s3.amazonaws.com/thm-monocle-interactive/gpyRY5W1Xj/Figure_07_05_04a.jpg

    10. Re:The sun is the center of all planetary orbits by Dunbal · · Score: 1

      Average out the "wiggles" and what do you get?

      --
      Seven puppies were harmed during the making of this post.
    11. Re:The sun is the center of all planetary orbits by iggymanz · · Score: 1

      You are very confused, the center of mass of the earth-moon system moves in an elliptical orbit, because orbits are elliptical. to the stool in the corner with the pointy hat, dunce.

    12. Re:The sun is the center of all planetary orbits by Anonymous Coward · · Score: 0

      > You are very confused, the center of mass of the earth-moon system moves in an elliptical orbit

      Maybe you are confused? The center of mass of the "earth-moon system" is empty space. It can't orbit anything.

      In actual fact, the Earth and moon are both orbiting the sun whilst simultaneously orbiting each other. And neither Earth nor moon follows an elliptical orbit.

    13. Re:The sun is the center of all planetary orbits by Anonymous Coward · · Score: 0

      > Average out the "wiggles" and what do you get?

      You get a path that Earth does not follow.

    14. Re:The sun is the center of all planetary orbits by Anonymous Coward · · Score: 0

      Oops, I spoke too soon. The Earth-moon barycenter is actually below the Earth's surface. The very diagram I linked shows as much!

      Still, with perturbations from other planetary bodies and the orbits' precession (think Spirograph), the most you can say is orbits are roughly elliptical.

  22. Of course it's pedantic by Headw1nd · · Score: 4, Insightful

    I saw some comments on the Physics Today article about this being pedantic, but astronomy is and always has been about pedantry. It's taking into account tiny details and vanishingly small deviations that allows us to do things like observe the composition of faraway stars or compute the age of the universe.

    1. Re:Of course it's pedantic by jythie · · Score: 1

      Plus.. why is that a bad thing? Some researchers posted a piece that played with language a bit and demonstrated a different way of viewing a linguistically ambiguous statement that produces an interesting alternative result. It doesn't actually change anything, but it still kinda cool and I think that is all it really was.

    2. Re:Of course it's pedantic by Anonymous Coward · · Score: 0

      Pedantry is exactly what this "research" is not. They assume a lot of stuff which isn't true to make the maths easier, and reach a conclusion that is totally self-evident without having done any calculations at all.

      Of course "which planet is closer to the earth" is going to be mercury; it spends it's time almost at the centre of our orbit, whilst the other planets spent half their time further away! It's a trivial and pointless finding by some PhD students who got high whilst watching Rick and Morty.

      In any case, physical proximity is only really relevant for communication lag; the important measure of how close something is is how long it takes to get there. By that standard you need three times the delta-v to get into orbit of mercury than either Mars or Venus, and IIRC it'd be easier to get to almost any of the moons of Saturn or Jupiter than Mercury (except maybe Io?).

      All told this research is so worthless that it's not even wrong, as Pauli would say.

    3. Re:Of course it's pedantic by Anonymous Coward · · Score: 0

      Who the hell are Rick and Morty? And while you're at it, who the hell is Pauli?

    4. Re:Of course it's pedantic by Headw1nd · · Score: 2

      the important measure of how close something is is how long it takes to get there.

      In astronomy? In astronomy the answer how far away something is might depend on how long it takes light to get there, but for most things astronomy the answer to how long it will take you (or any physical object we could launch) to get there is "you won't."

    5. Re:Of course it's pedantic by Trogre · · Score: 1

      It's not pedantry, it's changing the understood definition of "closest".

      This is taking the average distance between the celestial bodies themselves over a long period of time, instead of the common definition, the distance between the rings describing their orbits.

      --
      "Nine times out of ten, starting a fire is not the best way to solve the problem." - my wife
    6. Re:Of course it's pedantic by Anonymous Coward · · Score: 0

      Except according to the summary, they threw out the deviations both small and large and replaced them with circular planar orbits.

    7. Re:Of course it's pedantic by Anonymous Coward · · Score: 0

      I saw some comments on the Physics Today article about this being pedantic, but astronomy is and always has been about pedantry.

      It's not pedantic enough to me. Why circular orbits and 2D? 20 minutes with SPICE someone could write up and measure the actual distances. It would take less than 24 hours to run a few years worth of averaging. I don't see why they cheated.

    8. Re:Of course it's pedantic by Headw1nd · · Score: 1

      From the article it looks like they did. They apparently did the circular thing for proof of concept, then checked their results against 10,000 years of computed orbital data from a database. The circular approximation was off by about 1%.

  23. He hangs the earth upon nothing by Anonymous Coward · · Score: 0

    For this reason, God sends them a powerful delusion(operation of wandering)(planet) so that they will believe the lie.

    Mystery Red of the Great American Eclipse
    It has blood on it!
    ABCNews: Eclipse makes pendulum wander
    Church versus Galileo
    Sun researchers find strange eclipse reading

    1. Re:He hangs the earth upon nothing by Anonymous Coward · · Score: 0

      Ok, you're stupid. Next!

  24. Jensen's Inequality Strikes Again by K.+S.+Van+Horn · · Score: 1

    It's the same phenomenon as the fact that GPS overestimates the distance you've traveled:

    It's All About Jensen's Inequality

    1. Re:Jensen's Inequality Strikes Again by Anonymous Coward · · Score: 0

      Except that GPS receivers re-calibrate constantly. So, the error from the inequality is always at a minimum. Present, sure, but minimized.

    2. Re:Jensen's Inequality Strikes Again by K.+S.+Van+Horn · · Score: 1

      That is completely and entirely irrelevant. All that matters is that there is unbiased measurement error.

  25. Kepler says they're wrong by Anonymous Coward · · Score: 0

    Orbits are not all on the same plane. Orbits are elliptical.

  26. Enh. Ok. A curiosity. by roc97007 · · Score: 1

    ...but how is this useful?

    --
    Oliver's law of assumed responsibility: If you're seen fixing it, you will be blamed for breaking it.
  27. To the moon Alice! by Comboman · · Score: 1

    If we are counting things that aren't planets, the moon is much closer than the sun.

    --
    Support Right To Repair Legislation.
  28. Re:Enh. Ok. A curiosity. by Anonymous Coward · · Score: 0

    It's not.

  29. Re:Potato, Potaato by lgw · · Score: 3, Funny

    Seriously, there are more important problems to solve. How about something that's actually useful?

    Hey, now, this research evelated pedantry to a whole new level! If ever there was a story that belonged on Slashdot...

    But I don't get why they "simulated" this. Isn't this just an integral?

    --
    Socialism: a lie told by totalitarians and believed by fools.
  30. useless solution too by goombah99 · · Score: 1

    What does distance matter? If you are traveling to the planet you care about paths that don't clip the sun. Likewise if you are communicating with the planet you care about the average time it has line of sight to earth. And if you are launching a probe you care about closest approach to earth and relative velocity.

    --
    Some drink at the fountain of knowledge. Others just gargle.
    1. Re:useless solution too by danbert8 · · Score: 1

      Actually, the closest approach doesn't necessarily matter, especially for the inner planets as the traveled path usually uses gravity assists. Here is an example of Parker's path to get close to the sun:
      https://directory.eoportal.org...

      And one for Messenger going to Mercury:
      http://messenger.jhuapl.edu/Ab...

      It's not like you can take a direct route without using a shitload of fuel.

      --
      Yes it's an anecdote! Were you expecting original research in a Slashdot comment?
    2. Re: useless solution too by Anonymous Coward · · Score: 0

      A couple points: first, and very tangential is that traveling to an inner planet is more difficult because you have to go around the sun which has a massive gravity drag. But in average, it is not intuitive an likely wrong to say that we are closer on average to something that is closer to something else on average than something which is further from something else on average. Got it?

    3. Re:useless solution too by dryeo · · Score: 1

      Relative velocity is the big one for probes. It's actually easier to fly by Pluto then Mercury.

      --
      https://en.wikipedia.org/wiki/Inverted_totalitarianism
    4. Re:useless solution too by ceoyoyo · · Score: 1

      You're on the right track, but you didn't go far enough.

      If you're travelling to a planet, launching a probe, whatever, you don't give a crap about distance, paths that don't clip the sun, or closest approaches. You can about delta-v. And delta-v, particularly with their simplifying assumptions, is proportional to the difference between the two planets' orbital radii.

    5. Re: useless solution too by Anonymous Coward · · Score: 0

      And clipping the sun requires a buttload of dV, so it's a non-issue.

  31. Kendall, world's most boring faggot, matters not by Anonymous Coward · · Score: 0

    BORING FAGGOT KENDALL YOU WILL NEVER MATTER KILL YOURSELF

    Filter error: Don't use so many caps. It's like YELLING. Filter error: Don't use so many caps. It's like YELLING.

  32. Shit thinking by Tailhook · · Score: 1

    There is no 'misconception.' By 'closest' people have the orbits in mind, not the average vector distance. There is a clear rank of orbits from inner to outer and that's all that's meant be 'closest,' this stupid pedantry aside.

    One must instead average the distance between every point

    No one must not. One must stop publishing click-bait tripe like this.

    --
    Maw! Fire up the karma burner!
  33. Uhm.... on average, mercury is the closest.... by mark-t · · Score: 1

    ... to *EVERY* planet, isn't it?

    Why is this news?

    --
    File under 'M' for 'Manic ranting'
  34. Not research by ebcdic · · Score: 1

    This has always been obvious to anyone who thought about it for a while.

  35. Re:Potato, Potaato by Anonymous Coward · · Score: 0

    What more important problems are you working on? Oh right, you're reading slashdot, which is of course "actually useful."

    lol

  36. Re:Potato, Potaato by Immerman · · Score: 1

    Not really - the equation to reasonably accurately describe a planet's position in space is actually a pretty ugly kludge of approximations of the various perturbations it's subjected to, even in polar coordinates. Combine that with the math for finding the vector difference between two points as expressed in polar coordinates... the math is going to get ugly.

    A skilled mathematician would probably have no great trouble performing the integration, but very few scientists are skilled mathematicians.

    --
    --- Most topics have many sides worth arguing, allow me to take one opposite you.
  37. And the Sun by Tomahawk · · Score: 1

    Is even closer than Mercury, on average...

    "On average" can sometimes be a terrible way to measure anything, though. Many times it tells you absolutely nothing.

    A man can drown swimming in a lake with an average depth of 1"...!

    1. Re:And the Sun by angel'o'sphere · · Score: 1

      True. That is why so many don't grasp global warming ... average temperature increase of 1C or 2C has complete different meanings for every location.

      --
      Cost free eBook I read (by iBook/Kobo/Amazon/ObookO/Gutenberg etc.): "The Green Odyssey" by Philip Jose Farmer.
  38. Re:Potato, Potaato by Anonymous Coward · · Score: 0

    Now, here truly is a candidate to be sent at night to land on the Sun!

  39. Re:Potato, Potaato by Anonymous Coward · · Score: 0

    >> The researchers ran a simulation based on two assumptions: that the planets' orbits were approximately circular, and that their orbits weren't at an angle relative to one another.

    Original article

    So no, it's not the complicated proper math. They really should have been able to find the closed form solution. However, the lead author is a grad student who is apparently Python happy, so...

  40. Re:Potato, Potaato by Anonymous Coward · · Score: 0

    Seriously, there are more important problems to solve. How about something that's actually useful?

    This IS useful. We want to send M'Smash off-planet, for obvious reasons, but we really don't want to spend all that much to do it. Knowing that Mercury is generally the closest planet helps us plan.

  41. Re:Potato, Potaato by lgw · · Score: 1

    So no, it's not the complicated proper math. They really should have been able to find the closed form solution. However, the lead author is a grad student who is apparently Python happy, so...

    That explains it then. Heck, you don't even have to be able to solve the integral, that's what Wolfram Alpha is for.

    --
    Socialism: a lie told by totalitarians and believed by fools.
  42. Research is a joke by DarthVain · · Score: 1

    Literally:
    https://en.wikipedia.org/wiki/...

    So for the sake of this research lets assume that all planets are on the same plane (they are not). Lets also assume perfectly circular orbits (they are not).

    Any other assumptions they want to make? They pretty much took all the realism out of it already.

    What would be a really interesting question (and likely take a lot of computational power), is to look at the criteria for launching spacecraft using gravitational techniques, and calculate all of the optimized deployment windows for like the next 100 years, which are the shortest, shortest by planet, when, etc... Now that would be something. Also something useful (which the other is not), where if you see the next best window for a particular planet is coming up, and it won't be that good for another 75 years, you might you know, do something about it and plan ahead or something.

    1. Re:Research is a joke by PPH · · Score: 1

      Any other assumptions they want to make?

      Spherical cow in a vacuum.

      --
      Have gnu, will travel.
  43. The Sun is closer on average to any planet by Anonymous Coward · · Score: 0

    than any planet is to any other planet.

  44. Isn't this just an integral? by Anonymous Coward · · Score: 0

    Not in the "shuffling symbols around" sense, no.

  45. To paraphrase The Blues Brothers by Anonymous Coward · · Score: 0

    I hate Illinois pedants.

    Common understanding of "closest planet" refers to the orbits, not actual proximity.

  46. Re:Potato, Potaato by jschultz410 · · Score: 1

    If we are really going to get picky and bring gravity into this, then there is no known closed form solution for any of this.

    https://en.wikipedia.org/wiki/...

  47. not another one by Tablizer · · Score: 1

    Blasphemy! Lockem up with that Galileo bloke.

    --
    Table-ized A.I.
  48. The sun by John+Allsup · · Score: 1

    Likely a similar approach will show that, on average, each planet is closer to the sun than to any other planet.

    --
    John_Chalisque
  49. I'm pro-science and pro-learning BUT by Hallux-F-Sinister · · Score: 1

    Squandering taxpayer money on manned missions to uninhabitable waste planets is kinda pointless. You can't terraform MERCURY, VENUS, OR MARS ; on account of fundamental, unchangeable things about their natures. Mercury and Venus are too close to the sun AND too hot, Mars is too far away and insufficiently massive and too small to have enough gravity to hold an atmosphere of the kind that would be necessary for us to be able to BREATHE. Without it, we'd die. If you're going to fly away from Earth and build a colony of humans who have to live cooped up inside and only let out only once in a while in spacesuits, there's no real need to go so far as Mars. The MOON would be close enough. Anyway, just a thought.

    --
    Our reign has gone on long enough. Indeed. Summon the meteors.
    1. Re:I'm pro-science and pro-learning BUT by Anonymous Coward · · Score: 0

      As far as I know, Venus is not too close, and Mars is not too far away. Venus does have too much atmosphere and Mars too little, and Mars may be too small.

    2. Re:I'm pro-science and pro-learning BUT by Anonymous Coward · · Score: 0

      > Mars may be too small

      We can make it bigger (and warmer) by smacking a few thousand asteroids into it!

    3. Re:I'm pro-science and pro-learning BUT by SEE · · Score: 1

      Mars is too small to maintain a breathable atmosphere on a scale of millions of years, but it is large enough to hold a breathable atmosphere for tens of thousands of years, which is "good enough" for most human purposes. Nor is it "too far away"; it is very much close enough to the Sun that an atmosphere with sufficient greenhouse gasses could make the temperature comfortable, and the light intensity is sufficient to power photosynthesis.

      Now, whether terraforming an appropriate atmosphere is practical is another question.

      But even if you rule out terraforming, it's got distinct advantages over the Moon for indoor colonies. Substantially more gravity may well mean fewer negative health effects, for example. The appreciable atmosphere delivers usable volatiles for processing right to the colony's hatch, so you can be less perfect about avoiding losses. And the day-night cycle is appropriate for growing Earth crops in pressurized surface greenhouses rather than requiring massive amounts of artificially-generated light.

  50. Swimming in a lake with average depth of 1 inch by laie_techie · · Score: 1

    A man can drown swimming in a lake with an average depth of 1"...!

    Let me simplify that to a man can drown in 1 inch of water - no swimming required. Average (is that mean or median?) is almost always useless without standard deviation or chi squared.

    1. Re:Swimming in a lake with average depth of 1 inch by ceoyoyo · · Score: 1

      True for two-parameter distributions. Shocking, you need to know both parameters.

      It's not true for one parameter distributions.

  51. Re:Potato, Potaato by Immerman · · Score: 2

    True, but we don't need one - we're not trying to solve for the motion of an N-body system, we're trying to find the average distance between two bodies whose motion has already been well-characterized by observation.

    Our current approximations aren't perfect, but I believe they're generally accepted as accurate enough to project planetary positions for several centuries in either direction of the epoch.

    --
    --- Most topics have many sides worth arguing, allow me to take one opposite you.
  52. trivial mathematical facts by mapkinase · · Score: 1

    why

    --
    I do not believe in karma. "Funny"=-6. Do good and forbid evil. Yours, Oft-Offtopic Flamebaiting Troll.
  53. Sadly it is Right by Roger+W+Moore · · Score: 1

    If perfectly circular, average distance from any planet to any planet should be equal to the center of their path circle

    Sorry but that is wrong. If we assume that the Earth is fixed and we then look at the path of a purely circular orbit around the Sun we can draw a circle centred on the Earth with a radius equal to the Earth-Sun distance. Now if you look at the length of the orbit that is inside the circular you will see that this is less than half the orbit and slightly more than half the orbit is outside. Hence the average distance to the planet from Earth is going to be slightly more than the distance to the centre of the planet's orbit i.e. the sun.

    The reason for this difference is that there are two dimensions and the x and y displacements add in quadrature, not linearly. It's a subtle point but, as pedantically stupid as the article is, sadly it is not wrong.

  54. Pedantically Stupid, destined for QI by Roger+W+Moore · · Score: 1

    It's pedantically stupid, not interesting. What most people mean by the closest planet is the planet which comes closest to Earth during its orbit not which is closest on average. Indeed the example of Neptune which they give is particularly stupid since its orbit is 165 years long so even if you averaged over an entire human lifespan you would not get that result. What this really boils down to a silly wordplay but I am sure it will be amusing when it turns up on QI!

  55. Nobody gives a fuck...on average by Anonymous Coward · · Score: 0

    People care which one has the minimum distance to earth at any time during their orbits, not which one is usually closer to earth. Who the fuck cares?

  56. Re:Potato, Potaato by ceoyoyo · · Score: 1

    Not when you make their simplifying assumptions: perfectly circular orbits with zero inclination. As stated in the summary. It's not even an integral. It's the circumference of a circle.

  57. Re:Potato, Potaato by ravenshrike · · Score: 1

    More importantly it's still a shit way to measure distance since if you wanted to travel to the planets in question you would have to match orbit and velocity of the celestial body in question.

  58. Pedantic averages by Anonymous Coward · · Score: 0

    Users should always beware of using averages for non homogenius situations!

    For example
    The Average person has:
    1 head
    2 arms
    2 legs
    10 finger
    10 toes
    1 testicle
    1 breast

    what does the average person look like?

  59. Clockwise Revolution by Anonymous Coward · · Score: 0

    Anybody else bothered by the fact that "a team of scientists" have the planets revolving in the wrong direction?

  60. Re:Potato, Potaato by az-saguaro · · Score: 1

    If you want to track the planet to cm precision and account for every N-body chaotic perturbation, sure, what you said. But dude, it's an ellipse for all practical purposes. That's why we can have a calendar or farmer's almanac. Hell, you don't even need an integral. It's algebra. The position of Mercury or Earth can be plotted parametrically as x(t) and y(t), and then for any t you can solve sqrt (delta x^2 + delta y^2), (and indeed, you can integrate and divide by t to get the average). Next, for any so ambitious, calculate the mean distance from Mercury to YourAnus.

  61. You expect me to believe... by Anonymous Coward · · Score: 0

    Verily! My Excellent Mother Just Served Us Nine Pizzas?

    Oh right.... pluto...

    Verily! My Exibitionlist Mother Just Sent U Nudes!

  62. 100 years of science misdirection by Anonymous Coward · · Score: 0

    Hmm... we've had measurements of the inner planet orbits for 100 years and scientists just now figured out that they were wrong on the Earth's closet planet.

    Makes me wonder if the crisis in 5 years headlines drumbeat of science articles are credible.

    And to think scientists just recently discovered they were wrong about dinosaurs and birds after hundreds of years of it's proven that birds did not evolve from dinosaurs and dinosaurs didn't have feathers.

  63. Physicists discover geometry? by shess · · Score: 1

    I mean, yes? But doesn't this fall out of the geometry of Kepler's laws of planetary motion? I guess I'm confused how this isn't an April 1st article.

  64. when Mercury is furthest away from us by Anonymous Coward · · Score: 0

    it's still not that fat because it has a tight orbit with the sun... who knew. We don't need research for that. It's pedantic and impractical. What's not impractical is that it's orbit is faster so comms blackouts are more frequent but shorter.

  65. One can't ignore velocity by mce · · Score: 1

    The authors completely ignore the velocities at which the planets move. Their results may be kinda accurate for our solar system as it happens to be (but this should be checked properly), but they will still be "wrong" and surely are not as universal as their mathematical derivation/description suggests.

    By omitting the velocities, the authors ignore the fact that the distribution of the various distance values over time is not uniform. In the most extreme case, two planets might have the same angular velocity. Combined with the paper's assumption/approximation that the ellipses are de facto concentric circles, such planets would always maintain a constant distance between them, which can be anywhere between the minimum and the maximum described in this paper and very different from the average of all possible values.

    --
    Linux user since early January 1992.
    1. Re:One can't ignore velocity by jschultz410 · · Score: 1

      They didn't ignore the different orbital periods. That's why they used a uniform random distribution of all the planets on their orbits. The idea being that if you sample the planets all being randomly placed on their orbits enough times, then you approach looking at the planets over all time.

      Yes, this assumption and randomized analysis doesn't work if two or more planets are on the same orbit or have "locked" periodic orbits with one another.