Earth, sky and time — for the classroom
Free simulators, projector-ready, no sign-up. Open a lesson. Or send us one.
Astronomy in the classroom
Planets, the moon, the solar system — and a rocket that has to aim at where Mars will be.
Earth science in the classroom
Why the day/night line leans, why summer is tilt and not distance, and what the moon does to the sea.
Time in the classroom
Time zones, 12- and 24-hour clocks, the line where the date jumps — time as geography, not as a countdown.
Send us the lesson you already run
This site is one person building simulators, and the best thing that could happen to it is a teacher saying here is what I actually teach, and here is where it falls apart on a whiteboard. Send that. We rewrite it into a page on this site, built on these tools, with your name on it — free for every classroom that comes after yours.
You do not need a polished plan, an original one, or one you wrote without help. You need the right to share it. That is the entire bar.
This is a new program. Your submission would be the first. We rewrite it for the site, credit you the way you ask, and email you when it is live.
Submit a lesson plan Or just send the questions your class asked →
Or start from a lesson that already exists
Eighteen timed plans across five grade bands, each built around one question and each with every step wired to a live view. The whole grid is on lesson plans by topic and grade; a few to start from:
Every step carries its own minutes, which means any single step can be handed to a student as their own five-minute lesson. The student-taught section is built on exactly that.
Ask us to build something new
The third door, and the biggest ask: a simulator, not a countdown. What would make a concept land for your class if they could see it move? If it comes out of orbits, formulas or real measurements — an alignment, a cycle, a comparison, a scale you could walk out on a field, a body we have not drawn — it is probably within reach, and we will take it as a challenge.
Make the ask part of the lesson: let them argue about what would actually help, then send one email from the class rather than thirty. If we build it, the credit goes on the page it inspired — “inspired by an idea from Mr Smith's 5th grade class at Paradise Elementary School in Paradise, California” — which is a rare thing for a school task to end with: evidence, on the open internet, that the work changed something outside the room.
Need a countdown on the wall?
The timer and the stopwatch are still here, still free and still full-screen. They are not what this page is about — the projector timer, the keyboard shortcuts, the lap export and what a browser timer cannot be trusted to do all live on Time in the classroom.
Common questions
Do I need an account? No. There is no sign-up, nothing to install and nothing to pay. Everything runs in the browser on whatever machine the school gives you, and anything a tool saves stays on that device.
Will these work on a locked-down school computer? They are ordinary web pages, so if the browser can reach the site they work. There is no plugin, no Flash, no app and no login wall. The one thing worth testing before a lesson is sound, because some browsers need one tap on the page before they will play audio.
Are the simulators real, or are they animations? The positions are computed from the real orbits when the page loads, using the same standard methods observatories teach from — not a video and not a loop. Every page also states what its drawing exaggerates, which is usually the most useful thing on it. The one honest exception: where a moon sits along its orbit is illustrative, and the page says so.
Can I print, adapt or remix the lesson plans? Yes — free to use, adapt and share for teaching. You do not need to ask, and there is nothing to attribute unless you want to.
What actually happens if I send you a lesson? A person reads it. If we can use it, we rewrite it in the site's voice, wire every step to a live view, check the science, credit you the way you asked, and email you when it is live. If we cannot use it, we tell you rather than leaving you waiting. Nothing is ever published automatically.
Do you collect anything from students? No. There are no student accounts, no student forms, no uploads and no public comments anywhere on this site. The only address it ever holds is a teacher's, given on one of the teacher forms, and it is used to reply to that teacher. Class questions are published as “a 5th-grade class asked…”, never with a name.