Most solar system diagrams get the scale wrong just because a sheet of paper or screen is small. Shrink the Sun and Neptune down to fit on one page, and you have to shrink the distance between them by a completely different amount. Students end up picturing a solar system that's far more crowded than the real one.
This tool never fakes those numbers. Every planet size and every distance is rendered at its real, checkable scale. There are two views. One keeps distance true to life so students feel how empty space actually is. The other removes distance entirely so planets can be lined up at their true relative sizes. It runs in any browser, it's free, no ads, no tracking, and there's nothing to sign up for.
We should be direct about this. This tool doesn't do the standard's work for your students, and it shouldn't be used that way. MS-ESS1-3 and HS-ESS1-4 are both built around students doing the calculating themselves, either working out a scale factor from real diameters and distances, or applying Kepler's third law to predict a position. If they just watch a finished, correct model, they haven't done that part. This tool actually helps before or after that work, as a hook, as a way to check their own numbers, or as a way to reach past what a hallway model or a hand calculation can manage on its own.
| Grade band | Standard | What to use | Where it actually helps |
|---|---|---|---|
| 5th grade | 5-ESS1-1 | Distances view, Sol system, the Proxima Centauri marker | The standard asks students to construct their own argument for why the Sun looks brighter than other stars despite many being physically bigger. This gives them the distance evidence to build that argument from. The tool supplies the numbers; the argument is still their own writing. |
| Middle school | MS-ESS1-3 | Distances mode and Sizes mode, side by side | Best used after the math, not instead of it. Have students calculate their own scale model by hand first, using real diameters and distances and a chosen scale factor, then use this to check their numbers against an accurate rendering (Sizes mode has a Planets-only filter if you want moons and dwarf planets out of the way for a cleaner comparison). It's also good for going further than a hallway model can, like comparing dwarf planets or scaling out to a whole other system such as TRAPPIST-1. |
| High school | HS-ESS1-4 | Live, Kepler-solved planet positions | Have students predict a position or period by hand first, using Kepler's third law, then compare it against this tool, which solves Kepler's equation against real JPL orbital data for today's date. It's worth saying out loud in class that this is solving for position along an already-known orbit, not deriving the orbit from scratch. That distinction is a good five minutes of discussion on its own. |
If you only have one class period, start here. Open the Basketball Solar System. It rescales the whole solar system so the Sun is the size of a basketball. Before you reveal anything, ask students to guess how far away Earth would have to be at that scale. Most guesses land somewhere across the room. The real answer is about 85 feet. Then ask about Neptune. It's nearly half a mile out. That gap between the guess and the real distance is the entire lesson, and it takes about five minutes.
Want a different kind of hook, history instead of scale? Try the Ptolemaic System, the old Earth-centered model of the universe, built out accurately to its own internal logic. It was the accepted model of the cosmos for more than 1,400 years. That's a good way into a conversation about how scientific models change when better evidence shows up.
Click any of these to open that exact view. Project it, or copy the address bar link and send it to students directly.
Scroll from the Sun past Neptune and feel just how much empty space sits between the planets.
No scrolling, no distance. Just every planet lined up at true relative size.
The Sun shrunk down to a basketball. Good for the five-minute warm-up above.
A smaller, closer-in view of cislunar space. Good for younger students or a shorter period.
Seven real planets, all orbiting closer to their star than Mercury orbits the Sun.
Set to the exact same scale as that well-known single-scroll map. If your class already has a worksheet built around it, this drops straight into the same checkpoints, with each object's real numbers a click away instead of a scroll away.
This one flips the site's whole premise around. Instead of showing the real solar system to scale, it takes an atom and renders it using the same visual language as a solar system, a nucleus in the middle standing in for the Sun, with electrons arranged the way planets would be. Type "element" followed by an atomic number (or just "atom" on its own for a default carbon atom) to build one. Protons and neutrons are there too, and inside them, the up and down quarks that make them up.
The lesson is that atoms don't actually work the same way as a solar system. Electrons show up here as probability clouds, fuzzy regions rather than a small body tracing a fixed path. Students who picture electrons as tiny planets circling a nucleus, the classic Bohr model image most of them already have in their heads, get to see directly where that picture stops working. It's a good five-minute detour if you're already teaching atomic structure and want a more dynamic contrast than a textbook diagram gives you.
See a gold atom, built this wayNo login. No account. No ads. Nothing about your students is tracked or sent anywhere, ever. It runs in any modern browser, including school Chromebooks and iPads, and there is nothing to install. Everything here is likely to appease any district's device policy.
Yes. It's a normal web page built to work full screen. Open it, hide your browser toolbar if you like, and scroll or zoom from the front of the room.
Yes. Send students one of the ready-made links above, or build your own (see below) and post it wherever you already share assignments.
Yes. It's a browser page, not an app. There's nothing to install and nothing that needs administrator approval.
Inside the app, click the printer icon near the top of the screen. It generates a plain, printable report of whatever system is currently loaded, with the real facts and figures, so you can hand out paper copies.
Yes, and there's an easy way to do it without typing anything by hand. Get the view set up the way you want it (right seed, right zoom, right object centered), then click the share icon near the top of the app. A panel opens with checkboxes for what to include, your current location, your zoom level, your view settings, and a button that copies a ready-made link. Paste that anywhere you already share assignments.
If you'd rather build one yourself, or want to understand what's in a link a colleague sent you, the address bar is the whole story. Type anything into the System Seed box and it updates to match, for example ?seed=sol. A few more pieces you can add by hand.
&mode=distances or &mode=sizes picks the view.
&scale=10000 sets the zoom level in kilometers per pixel. Smaller numbers zoom in further.
&target=Earth (or any object's name, no spaces) opens the page already centered on that object.
Put them together and you get something like https://solarsystem.dunakin.com/?seed=sol&mode=sizes&target=Jupiter, which opens straight to every planet lined up with Jupiter already in view.
That page is a great, simple way to feel the distance, and there's no reason to stop using it. This tool can be set to the exact same scale (see the matched link above), so any worksheet or WebQuest already built around it still works here. What this adds is the ability to jump straight to an object instead of scrolling the whole way there, a second view that eliminates distance and lines the planets up by true size, live positions solved from real orbital data instead of a fixed snapshot, and a printable handout of distances and diameters for students. A good pairing is to run the pixel scroll first for the "wow" moment, then switch here for the follow-up questions.