Scale the solar system

By Phil Plait | November 24, 2009 12:28 pm

Speaking of web pages showing scale (OK, it was almost two weeks ago, but still cool), BABloggee Mike Sperry reminded me of this site which shows the solar system to scale… all on one web page! The Sun is displayed when you go to the page, and you can scroll to the right to see the planets, drawn in scale both in size and distance.

The Sun is about 560 pixels wide, putting Pluto something like 2 million pixels to the right. And some people wonder why it’ll take the New Horizons mission 9 years to get to Pluto…

CATEGORIZED UNDER: Astronomy, Cool stuff

Comments (56)

  1. DrFlimmer

    Reminds me of the city Hagen (Germany). The sun is sitting right on top of the town hall. Then you can find all the orbits on the ground in the right distance. I think, Pluto is about 2km out.

    Of course, there are many places on this earth, where such a nice model has been placed 😉

  2. Donnie B.

    That’s a great page. (I’d seen it before.)

    It’s pretty impressive how far even Mercury is from the Sun — it takes a lot of page-scrolls to get to it. The outer planets… forget it.

    One addition would be nice: the major moons in scale and at proper distances from their primaries. I sorta missed old Luna, not to mention the Jovian and Saturnian systems.

  3. If the solar system is that empty, think how empty the universe is.

    Take all the visible universe (think of the Hubble Deep Field and those Tyson pictures where the sky is essentially covered by faint blue galaxies) and compress it to the density of something we understand well: nuclear matter. (Ignore any effects of strong gravity.) How big will the ball be? It will comfortably fit within the asteroid belt of our solar system.

  4. Keith (the first one)

    That’s really good. Is the text also to scale, because I always wondered how big the paragraphs at the beginning of Star Wars are. lol

  5. FC

    Phillip are you talking about a ginormous atom? Or perhaps a ginormous ball of neutrons?

  6. Cory Meyer

    I’m scrolling, and scrolling, and scrolling, have passed by Mars. Does anyone know what approximate distance is represented with one pixel? Okay, now back to scrolling… :)

  7. “Phillip are you talking about a ginormous atom? Or perhaps a ginormous ball of neutrons?”

    Yes. Of course, if this really happened, one could not ignore the gravitational effects. The illustration is just to give an idea how thinly spread matter is.

  8. Eric

    I find it wonderous that New Horizons will reach Pluto in as little as nine years.

  9. Alaskana

    That was cool. Now I’d like to see the same scale model, but with Alpha Centauri included. It would put the term ‘the next nearest star to Earth’ in proper perspective.

  10. Eric H.

    If you are having trouble finding the planets just by scrolling (I know I was). You can take a shortcut to each planet just to see how far along the scrollbar it is by appending #planet-name to the end of the url.

    Example: will show Earth and will show Saturn.

  11. In the text next to the Sun there is a link to jump to Pluto. You can edit that link in your browser’s address bar to jump directly to any planet. For example, change the name after the “#”:

    6. Cory Meyer: Chrome’s Inspect Element tells me that the page is 2,382,625 pixels wide. With an average distance from the sun of about 6.08919 x 10^9 km, that means about 2555.67 km/pixel.

  12. Kees

    Thank God for middlemouse-press-scrolling… I went past Earth before I knew it at Warp 4 or something.

  13. Cool site. Some asteroids would have been nice, too.

  14. Chas, PE SE

    Many years ago, I build a scale model of the solar System for my daughter’s Girl Scout troop. The Sun was (conviently) the size of a 200 watt light bulb — about 4 inches in diameter. The Earth was 0.02″ and a bit less than 100 feet away, Jupiter was 3/8″ and 400 feet. Pluto would’ve been something like 4,000 feet (as I fautily recall). I used an Excel spreadsheet with the diameters and orbits loaded, and divided it by a proportion. I could key that up or down until I got something I could build — orbits close enough to space out, but with planets big enough to see.
    The thing that impresses me is all the hoo-raa about the planets being in conjunction, throwing the Sun off or knocking the Earth out of its orbit. When one can see how big the Solar System is, and how small the planets are, it is immediately clear how silly this concept is.

  15. jf

    The model mentioned by #1 DrFlimmer is at (in German).

    I think I went past Jupiter on my way to the dentist’s clinic in Bahnhofstr. 😉

  16. Mapnut

    Tom Hill: The asteroids are there, they’re just smaller than a pixel. 😉

  17. JeffS

    Nice model. They should have an automatic javascript scroller that moves you from the sun at c (or some multiple of).

  18. Try the software “Celestia” ( to get a sense of distance / size. I could fly around in it for hours. :-)

    I downloaded a “warp drive” simulator for it. The 8-minute flight from the sun to the Earth at the speed of light is a good perspective on things, and flying by the Earth at that speed actually seems slow.

  19. toasterhead

    11. Dennis Says:
    November 24th, 2009 at 1:53 pm

    6. Cory Meyer: Chrome’s Inspect Element tells me that the page is 2,382,625 pixels wide. With an average distance from the sun of about 6.08919 x 10^9 km, that means about 2555.67 km/pixel.

    So if I’m doing the math right, one light year will be 3,701,859,188 pixels. If Proxima Centauri were on this page, it’d be 16,177,124,654 pixels away. That’s 3,546 miles away, at 72 dpi – the distance from Atlanta to Leeds.

    That’s a big monitor.

  20. 17. JeffS: Even the newest versions of JavaScript can’t go faster than the speed of light. And everybody knows that even C goes at, well, the speed of C. 😉

  21. Here’s another site to give you all a sense of how empty space is:

    Scroll down a little and you can enter the diameter of the Sun in your model and the system will output all the relevant numbers. I carry a little orange superball in my pocket that I use as an outreach tool. The nearest star (with this ball as the Sun) from Charlottesville, Va. is in Chicago.

    I make a point of asking all the groups to which I give talks to make a guess how far that Alpha Centauri (OK, ok, proxima) is at that scale. Only 1 person in 3 years has come close (with a guess of Saint Louis).

  22. twilightened

    Don’t bother with the web site. Just download Mitaka, and really see the scale of not just the solar system, but all the universe as we know it today. I was stunned. Here:

  23. What about rebuilding this page with a CSS design instead of a table?

    /Just saying…

  24. Kurt Erlenbach

    I helped my daughter years ago build a scale model of the solar system for her elementary school science fair. We live in Titusville FL, directly west of the space shuttle launch pads. The road the school is on runs due east, and drawing a straight line east ends at pad 39A and the Atlantic ocean, about 17 miles east of the school. We calculated the distance from the school to the launch pad, and then figured out the sizes and distances based on the sun at the school and Pluto (this was back when Pluto was still a planet) at pad 39A. She built the planets, and then we put them at the appropriate places along the road through town and out toward the pad. The sun was yellow paper on the wall of the cafeteria about 17 feet in diameter (if I remember correctly). Mercury was a BB at the gas station across the street, Venus was a small wooden ball under the I-95 overpass, Earth and the moon were about 3 feet apart from each other at another gas station on the other side of the overpass, as so forth. NASA wouldn’t let us put the Pluto display at the pad, but we got a nice picture of her holding the BB-sized Pluto right in front of the the pad, courtesy of the NASA PR folks, looking sort of like the photo of Phil at the top of the blog. It was a darn cool project. It really teaches you something about the size and scale of space to see it laid out that way.

  25. Sorry for the off-topic, but I wanted to point out to Phil that Google Adsense is placing ads of an ID course below this same post on Google Reader.

    Just thought you should know.

  26. Darth Dog

    There is another really cool (and very large) scale model of the solar system near Coonabarabran, NSW, Australia. The sun is represented by the dome of the Siding Springs Observatory and is 37 meters in diameter. Scale models of the planets are placed alongside highways. Pluto is about 200 kilometers away! It really gives you a sense of the scale of the solar system when you leave the observatory and don’t pass Pluto until you have driven for several hours.

  27. Wayne on the plains

    I’m glad to see this page (and so many commenters) building actual scale models. I was always annoyed with the astronomy labs that had students calculate the sizes and distances of the solar system at different scales, it really doesn’t give you the same appreciation of things. On my campus, we use a globe streetlight as the sun, small beads for the inner planets etc. The only down side is that I can only get to Saturn before I run out of campus, and Pluto is halfway across town, but it still gets the point across. Another nice thing about it is you can point out when you get to the Earth position that the model Sun is the same apparent size as the real Sun, which helps when you’re trying to explain why the Sun and the Moon appear to be the same size in the sky.

  28. @Kurt Erlenbach: Pluto is still a planet. Please do not blindly accept the controversial IAU demotion, done by only four percent of its members, most of whom are not planetary scientists. That decision was opposed by hundreds of professional astronomers in a formal petition led by Dr. Alan Stern, Principal Investigator of New Horizons.

  29. Robert

    I think they tried to build a scale model in Utrecht, the Netherlands (where I studied astronomy) at some point. The sun is a 1m diameter copper sphere sitting in front of the academy building (where all diploma’s are handed out). After that, the city cancelled the funding…

    Earth’s orbit would have been at the canal marking the historic city border. The gas planets would have been in the center of various nearby towns. Alpha Centauri would have been in Moscow.

    Of course, I’m not sure how much of the story is real, it sure was a great story for my lecturers to tell though!

  30. And I thought it was a long way down the road to the chemist’s.

  31. I found the Solar System to Scale site with StumbleUpon on Monday morning. I decided to see how long it would take me to scroll over to some of the planets. After about 20 minutes I’d gotten as far as Jupiter. I figured the scrolling was occurring at about twice the speed of light. Since I was only about 1/7th of the way across the image at that point, I decided not to keep scrolling.

    By the way, it says on the site that one pixel equals one thousand kilometers.

  32. Space Cadet

    I helped my daughter build a solar system model many years ago. We were constrained by the distance from the teacher’s desk to the nearest busy road, and by the stipulation, imposed by my middle-infielder daughter, that the sun be a softball, but we taped various objects, decorated if size allowed, on a couple of kids’ desks and a bookshelf, some posts in the buildings and light poles in the parking lot until Pluto, the point snipped off a pin, was taped to the traffic signal at the afore mentioned busy road. It wasn’t exactly scale, but for a bunch of second graders, I think it worked pretty well. And it was fun.

  33. EmaNymton

    Hey. A cameo by Pluto-troll Laurel Kornfeld! Everyone who wants to know anything about the Pluto thing needs to read what she has to say. That’s what took me from being not sure about the whole thing to being quite sure that the decision was correct.

  34. James B

    A little point of confusion, Phillip in #7 answers an “Either/Or” question with “Yes”, would he mind clarifying the point? the difference between a big ball of atoms and a big ball of neutrons is so huge, I’m not sure which is the correct interpretation of the analogy. I’m only a lay person to science, but I understand enough to know the massive difference between these two scenarios and would like to be furnished with the correct interpretation, since its an interesting analogy.

    Also, for the scrolling site, holding down scroll while the screen seems to stay a static black doesn’t really give you any idea of the distance you’re scrolling. Some kind of scale or reference point for the scrolling I think would really enhance the appreciation of distance. Maybe a scale along the bottom giving distance in kilometres, or light seconds/minutes?

    I really like the idea, scales on a solar system/galactic level as well as an atomic level are so removed from human experience, aides like this are extremely useful, not to mention downright fascinating!

  35. Vern

    With all that nothing out there I’m just happy we have something to perch on at all.

  36. Tervuren

    I am a Special Education teacher. One of my favorite activities for teaching the Solar System is called “Earth as a Peppercorn” . We glue common objects that simulate the relative sizes of planets to popsicle sticks, using a volleyball for the sun; and then pace out the distances and stab the sticks in the ground. We usually run out of playground before we place Saturn (a hazelnut). It is a fun craft and whole body activity for students.

  37. James B

    rereading through all these comments, its quite heart-warming for someone concerned with science education to see so many stories of recreations readers have done. Power to the people!

  38. Autumn

    Mike Marsh says “And I thought it was a long way down the road to the chemist’s”

    Yes, I have to say it, “That’s just peanuts to space.”
    Thank you Douglas Adams

  39. The Hitchhiker

    If anyone is a Pluto troll it’s Mike Brown who obsessively refers to himself as Plutokiller and rants on and on about how his fantasies of bombing Pluto. This guy is nothing but a troublemaker in the astronomy community. Then he tries to soften his image by shamelessly using his kid as a pawn, always talking about Lilah this and Lilah that. I was undecided too until I started reading about this nut.

  40. 21. Richard Drumm The Astronomy Bum Says: “Here’s another site to give you all a sense of how empty space is:

    Thank you for that! We have a local city park, located on the rural edge of Livermore, that has roughly linear main trail that’s just over 3.5 miles long. I’ve always thought that it would be the perfect place for a 1:1,000,000,000 scale model of the solar system. The sun would be about 52″ (1.3m) in diameter, an impressive enough size for when you get to the planets (Earth is just over 1/2 inch (1.3 cm)). With the sun at one trail head, Pluto would be at the other end, an hour or more walk away.

    – Jack

  41. Kristin C

    Fabulous! The physics institute here did that scale model every year on our campus as a centre attraction for the Astrofestival at the University of Oslo Campus. The Sun was the size of an orange and the planets were strewn out as little led lights on sticks, and then we guided groups of schoolchildren around (as well as adults).

    (Unfortunately, the Astrofestival didn’t get enough money support to continue beyond 2008, a giant shame for the International Year of Astronomy. It will however ressurect as a one-time festival in 2011 when the University celebrates its 200 year anniversary.)

  42. StuartB

    @DrFlimmer: there’s a similar scaled solar system on a mile of cycle path between York and Selby, which comes complete with signposts at each planet giving the distances to the next and previous:

  43. 31. MobyD Says:
    By the way, it says on the site that one pixel equals one thousand kilometers.

    Where did you see that? Because I don’t.

  44. dd

    That’s cool. It’s very hard to find, say, Saturn scrolling on the screen in this super-resized down model. So, think about the ability of scientists that send spacecrafts that go from Earth to Saturn and beyond in the real Solar System. And they get to the right place with an approximation of few kilometers… That’s amazing… :-)

  45. @ Jack Hagerty:
    You’re welcome! I’ve had that site bookmarked for a few years now. Very useful! That link will give you the hard data you need for your design. Easy peasy!

    @ Laurel & The Hitchhiker:
    It’s time you moved on from this topic. Pluto is a snowball in a weird orbit. It cares not what we call it. Like I tell the kids at the Observatory, we could call it a chicken if we wanted.
    4th graders everywhere will be glad they don’t have to memorize 100 planets for some test.

    Even so, it would be fun for us BAblogees to come up with the mnemonic to supplant the “My Very Earnest Mother Just Served Us Nachos” that we now have. I have a list of some of the KBOs but not their distances… Anybody out there have a link?

    Quaoar could be quail, Varuna could be vegetables, and so on…
    Oh, Makemake just MUST be mahi-mahi! Yum!

    @ #5 FC:
    It would be a ball of neutrons. Neutron star stuff. Very dense. Very cool, too!

    As I used the scroll bar’s arrow “key” to scroll through the graphic I used the timer in my iPod and found that it took 13 seconds to scroll from the Sun to the Earth. Since this would take 8 minutes at lightspeed, this means that scrollspeed is 37 times lightspeed! (8 X 60/13)Even then, it takes approximately FOREVER to get to ol’ Pluto! I tried dragging the scroll thingie to find the other planets and failed to find Neptune. It must zip by so fast it’s not even displayed. Wow.

  46. if i print this out how many black ink cartrages am i going to need?

  47. mike burkhart

    this site was interesting but some think the solor system ends at the orat cloud were comets form and its 2 light years away form the sun

  48. There’s a science teacher in Loudon county, Virginia, who’s looking to do a countywide “to scale” layout of the solar system. The article is from last spring, and I’m not sure whatever became of the idea. Pretty cool, though, if he manages to pull it off.

  49. KC

    >If anyone is a Pluto troll it’s Mike Brown

    Surely you jest – Laurel is the A Number 1 Pluto troll. She comments on every single article even remotely related to Pluto!

  50. gopher65

    @EmaNymton #33:

    The reason why the IAU’s decision was stupid has nothing to do with Pluto itself. I don’t care what it is called. They could classify it as a comet for all I care.

    The problem with their definition of planet is that if we find a gas giant the size of Jupiter way out in the Oort cloud, it would *not be considered a planet* ((even if it is shown that it formed close in around Sol like the other plants and got booted out to that distant orbit (not sure how you could show that, but let’s just say)).

    Whether or not an object can “clear its neighbourhood” depends on two things: how big the object is, and the size of the region covered by its orbit. If the orbit is too large, not even Jupiter (or the super-gas giants discovered in other systems) can clear it out in a reasonable amount of time (ie, the lifetime of the universe:P). Thus, under this *ridiculous* new definition, Jupiter wouldn’t be a plant if it had a larger orbit. And Mercury could have a positively tiny orbit (tiny in the grand scheme of things anyway) and not be considered a plant.

    In short, this definition is fraking lame. It was voted up not based on the merits of the definition (it has no merits whatsoever), but based on ideology. And that’s just sickening.

  51. Inverse,

    I love Celestia. It’s one of my great Time consumers. I fire that program up and half a day can go by before I find the wherewithal to shut it down. It really gives a fantastic perspective on the enormity of what surrounds us. I even used it to look at some of the orbital issues that may have been in play in the Doctor Who episode The Waters of Mars.

    The only problem I have with it is that whilst it shows the motions of objects within the solar system, it does not show stellar or galactic motion.

  52. lcdlover

    Does anyone know Boston? It is said that if one stands on the top of the hi-rise MIT building in Cambridge (the one with the big sphere on top) and hold up a grapefruit, that grapefruit would represent the earth, and at the exact proportional size and distance, the sun would be the gold dome of the Massachusetts State House on beacon hill. This image is especially striking because both are clearly visible as one transits the Longfellow or Mass Av bridges.

  53. @Richard Drumm No one should “move on” from a bad decision, and I certainly never will. How about the IAU “move on” by admitting they goofed on this one? Pluto is not an iceball; it is estimated to be 75 percent rock. An eccentric orbit does not preclude it from being considered a planet, as many giant exoplanets we have discovered have orbits far more eccentric than Pluto. And you don’t need to tell your fourth graders to memorize the planets. Memorization is not important; understanding the different types of planets and their characteristics is. We don’t shorten the Periodic Table of the Elements to make it easier to memorize. We don’t say Jupiter can have only four moons because no one can memorize 63.

    And KC, I am an astronomer working to get the ridiculous IAU demotion overturned. I may soon qualify to join the IAU. I have just as much right to a voice on this as Mike Brown.


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