‘If The Moon Were Only 1 Pixel’ – A Real Deal Solar System Simulator

Click to enjoy a journey across our spacious solar system courtesy of Josh Worth.

How do you picture the solar system? Most of us imagine the eight planets as colorful balls of varying sizes moving in orbits that comfortably fit within the confines of our computer screens. But is that how it really is? Maybe as a handy reference, but the real place is far different. A new simulator that shrinks the moon to one pixel goes a long to help us appreciate its true vastness.

Is this how you picture the solar system? You’re not alone. The true scale of the real version may surprise you. Credit: ESO

In my astronomy classes, I try to convey a sense of how small the planets are compared to the abyss of space by playing the “Honey, I shrunk the planets” game. If the sun’s the size of a softball, Earth’s a sphere the size of a grain of salt (~1 mm) 38 feet away. Jupiter’s a little larger than a penny and 200 feet away, and Alpha Centauri, the nearest star beyond the sun, flickers 2,000 miles from home.

OK, that’s not bad, but maybe not visceral enough. Somehow we’d like to feel the distance, sense the emptiness. That’s where the new simulator If the Moon Were Only 1 Pixel excels.

Planets and the sun are shown to scale in “If the Moon …” with the moon represented by a single pixel. Credit: Josh Worth

Created by Josh Worth, a graphic artist and writer from Los Angeles, the simulator uses a horizontal slider to scroll you from one end of the sun’s neighborhood to the other. You can use the scroll bar at the bottom of the page, your keyboards’ arrow or, if your mouse allows or you’re using a touch pad, move along with repeated flicks of a finger. Planets sizes are based on the moon, which Worth has shrunk down to one pixel.

I found that scrolling from Mercury to Venus to Earth took some time but was hardly taxing. It was traveling to Jupiter that blew me away. Worth entertains along the way with funny tidbits and facts, but I swear the next time I look up at Jupiter I’ll have a better appreciation of how much space separates our two worlds.

Not that you have to scroll, scroll, scroll. Just click on a planet’s icon at the top of the screen and you’ll be whisked there in a jiffy. I suggest you pour a cup and savor the journey.

19 Responses

    1. astrobob

      Interesting. The link you have is based on the exact same idea but not as entertaining or informative as Worth’s version.

      1. Giorgio Rizzarelli

        I quote, those comments are funny. They elonged my patience to scroll at one planet more, Uranus – after that, I had fingers burned from scrolling. Another additional feature are the planet-shortcut buttons at top.

        At last weather is good here. We had an unusual January and February with higher temperatures than average (few days requiring winter jacket..), just about 8 clear days, and rain more frequent than usual (at least it seemed so). Still in mid February an important weather Italian site reported a thermography showing clearly the hot spot at pole above Europe (between the cold spots of Siberia and Canada) – extending down to all Europe ad Africa. I don’t know it it’s related, but one day we even had dirty rain with sand coming from Sahara. Now weather seems back to ordinary, and finally we’ll have at least a week of clear days. A few days ago the skies opened at surprise during the night, with a quite shiny Mars dominating the night.

      1. Bob Crozier

        Bob: you’re a photographer. Can you tell me why, if he is taking a picture of the aurora (which I assume would mean at least a slightly longer exposure time) why there is no apparent movement (blurring, streaking) in the image of the asteroid? Was it essentially coming straight at them?


          1. Bob Crozier

            Hi Bob,
            I was referencing the photo of the exploding fireball (Yellowknife NWT) in the article referenced by BC stargazer above (Mar 7, 2:56PM). Sorry I didn’t provide any context. You probably don’t get to see the thread when you see these messages being posted, eh?

          2. astrobob

            Hi Bob,
            While the aurora was taken with a time exposure, the fireball flared and faded from view quickly, “etching” itself into the longer exposure. I’ve caught a few meteors myself this way when shooting time exposures of other night scenes.

  1. Timothy Fleming

    Do you think anything happened in the asteroid belt (big collision?) – resulting in the 3 recent asteroids fly-byes? Seems to be too coincidental.


    1. astrobob

      Hi Tim,
      There are so many small Earth-crossing asteroids (~150 million 30-foot objects, 300,000 300-footers) that the chance of these 3 being related to the breakup of one particular asteroid is remote though possible. Lots of these small ones zip relatively near the planet every single month. Also, all three of these have different orbits.

  2. Norman Sanker

    Hey Bob, what blew my mind the most was the emptiness of a hydrogen atom making this neighborhood look positively crowded. If the one proton nucleus were the size of the sun pictured here, it would take 12 times the length of this scroll to reach the electron. Whoa.

    1. astrobob

      I agree Norman. I’ve seen that on the web as well, and it might not have been a bad idea to have included it to show how spacious everything is at a micro-level as well.

    2. Bob Crozier

      That is astounding, isn’t it?! It got me to wondering… if a single proton were the size of the Sun, what would its mass be on that same kind of scale? Would that make it something equivalent to a super-massive black hole? Would that explain how a proton can hang on to the electron at kind distance and at the incredible speed that it orbits?

      1. astrobob

        Electrons are only about .054% as massive as a proton. Electromagnetic force keeps the electron “spinning” around the nucleus. Of course they’re not really little balls whirling around the central protons and neutrons. According to quantum mechanics, they’re “clouds” of negative charge located at discrete levels from the nucleus. One proton = 1.6725 x 10 to the negative 24 grams and the sun is made of mostly protons and electrons. If you pushed them extremely close together, they’d combine to form neutrons and if you pushed those even closer, you’d get a black hole.

        1. Bob Crozier

          Hi Bob,

          What I was trying to ask was if a single proton could be scaled up to the size of the Sun (as suggested by Josh’s comment and referenced in Norman’s post above), would that proton then be as massive as a black hole? So I did a little digging and tried to play with some numbers to figure this out. But it has been nearly forever (ok, that’s a slight exaggeration) since I tried doing things with numbers like this. Tell me if I’m close.

          A single proton is about 1.6 x 10^-15 meters in diameter. The Sun is about 1.392 x 10^9 meters in diameter. So does that mean the diameter of the Sun is about 0.82 x 10^24 times bigger than the diameter of a single proton? Then I went hmmm… you mentioned that a proton has a mass of 1.6725 x 10^-24. Does this actually mean if a single proton could be ‘zoomed up’ to something the size of the Sun and if it’s mass were adjusted at the same scale or rate, that it’s entire mass – even though it were the size of the Sun – would still only be 1.3735 grams??!! And that little tiny bit of mass can ‘hang on to’ an electron with a mass of about (at this scale) 0.00074169 grams in an orbit with a radius of about 70,980,974,880 km??!! That’s a distance of about 65.77 light hours or 2.74 light days. That is not as far as the Oort Cloud objects are speculated to be from the Sun, which, according to Wikipedia, might be up to 1 light year from the Sun. But that is still an astounding distance, especially if you consider the equivalent mass at that scale! And – maybe most astounding of all! – there would be absolutely nothing else at all in between that proton and that single solitary electron ‘cloud’… just empty space.

          1. astrobob

            Well, let’s see. If you zoomed up a proton to be as big as the sun, first it wouldn’t be a proton anymore. Protons are what they are: very tiny creatures made of two “up” quarks and one “down” quark. Since the sun’s mass is about 90% protons, it’s already sort of a big proton but of course composed of billions of them. But if you’re talking scale only, yes, if you inflated a proton to the size of the sun, the corresponding distance of the electron from it would be phenomenally large, on the order you calculated. The analogy you make vividly demonstrates how utterly empty atoms truly are. As for the mass of a proton the size of the sun, since it’s impossible to create such a beast, the closest we can come is the current sun, composed of 90% protons with the remaining mass as neutrons, electrons, neutrinos and other subatomic particles. It’s heavy alright, containing far more mass than all the planets combined, but far from black hole-dom. For that to happen, all that material would have to be squeezed down to a ball about 3 miles across.

  3. Bob Crozier

    Josh Worth wrote, “It seems like we are both pathetically insignificant, and miraculously important at the same time.” (4216243702 km)

    Now that’s saying a mouthful! There may be more truth to that than most of us realize.

    1. astrobob

      Or as Neil deGrasse Tyson said: We’re insignificant on the scale of the cosmos but think big thoughts.

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