Most solar system diagrams get the scale wrong simply 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.
Solar system scale and orbital motion are part of several standards, including NGSS, IB, AP, IGCSE, TEKS, FL SC and others. Whatever your framework, the underlying ask should prompt students to calculate their own answers through observing extreme distances, theorizing, working out a scale factor from real measurements, applying Kepler's third law to predict a distance from the Sun, or other equations. This tool is built to support that work, serving as a hook before students start, a way to check their numbers once they're done, or a way to go further than a hallway model or a hand calculation can reach on its own.
| Grade band | Standards | What to use | Where it actually helps |
|---|---|---|---|
| Grades Kâ2 | NGSS 1-ESS1-1 NGSS 1-ESS1-2 K–2 DCI ESS1.B |
The Earth-Moon view (seed earth), projected, plus the printable handout |
These standards ask students to observe and describe patterns in the sun, moon, and stars. Project the Earth-Moon view as a simple, labeled picture of what's actually up there, then take the real noticing back outside: watch where the Sun comes up and goes down, and track how many hours of daylight there are as the seasons change. The app can preview what the objects are and look like; it can't substitute for the day-to-day sky-watching these standards are built around. |
| Grades 3â5 | NGSS 5-ESS1-1 NGSS 5-ESS1-2 3–5 DCI ESS1.B |
Distances view, Sol system, the Proxima Centauri marker | For 5-ESS1-1, 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. 5-ESS1-2 asks students to graph their own shadow, day/night, and seasonal star observations. This tool doesn't collect that data for them, but the view is a good way to show why those patterns exist: Earth's real position relative to the Sun changes throughout the year, rather than being aligned with other objects. |
| Middle school | NGSS MS-ESS1-3 TEKS 7.9A (TX) SC.8.E.5.7 (FL) |
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 a whole other system such as TRAPPIST-1. |
| High school | NGSS HS-ESS1-4 IB Physics HL/SL (Kepler's laws) |
Live, Kepler-solved distances from the Sun | Have students predict a distance from the Sun or an orbital 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 stating a limitation directly here: this site shows each object's distance from the Sun, not the distance between two objects. Earth and Mars can each have an accurate distance from the Sun on this page while sitting on opposite sides of it, so the distance between them isn't something this tool can answer. That gap is worth a few minutes on its own, since it's the reason Mars launch windows only open once every 26 months. |
| Middle & High school | NGSS MS-ESS1-2 (disk-formation DCI) NGSS HS-ESS1-6 |
The Proto-Solar System (seed proto-sol) |
HS-ESS1-6 specifically asks students to use evidence from meteorites and planetary surfaces to construct an account of Earth's formation and early history. This preset gives them something concrete to reason about: a fainter young Sun, Theia sharing Earth's orbit just before the collision that made the Moon, Jupiter's Grand Tack migration, and a Saturn without rings yet. It's built and labeled as a composite, illustrative reconstruction rather than one verified snapshot in time, which makes it a natural way into a discussion of how scientific models get revised as new evidence comes in, one of the Nature of Science ideas HS-ESS1-6 is built around. |
If you have limited time for a lesson, 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 (26 meters). Then ask about Neptune. It's nearly half a mile out (776 meters). 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.
A composite, illustrative reconstruction of the early solar system: Theia sharing Earth's orbit, Jupiter's Grand Tack migration, a fainter young Sun. Pairs well with HS-ESS1-6.
This one flips the site's whole premise around. It takes an atom and attempts to render it using the same visual language as a solar system, a nucleus in the middle standing in for the Sun, with electrons where one might imagine 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 pictured electrons as tiny planets circling a nucleus (the classic Bohr model), 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 materials on paper.
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 distances solved from real orbital data instead of a fixed snapshot, and a printable handout ( icon) 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.